WO2025004101A1

WO2025004101A1 - Electrocatalyst for conversion of biomass component(s) into value-added chemicals and concurrent green hydrogen production

Info

Publication number: WO2025004101A1
Application number: PCT/IN2024/050924
Authority: WO
Inventors: Chinnakonda Subramanian GOPINATH; Kshirodra Kumar Patra; Inderjeet Chauhan
Original assignee: Council of Scientific and Industrial Research CSIR
Current assignee: Council of Scientific and Industrial Research CSIR
Priority date: 2023-06-26
Filing date: 2024-06-26
Publication date: 2025-01-02
Anticipated expiration: 2025-12-26

Abstract

The present invention generally relates to electrochemical reactions and catalysts thereof. Particularly, the present invention relates to palladium-based electrocatalyst and its process of preparation thereof for electrochemical oxidation of biomass component(s) into value-added products and green hydrogen production, and without the generation of CO2 gas. More particularly, the present invention relates to a process of production of value-added product(s) by reacting said biomass component(s) with said palladium-based electrocatalysts under the electrochemical setup comprising of a voltage applied for oxidation in the range of 0.4 to 1.2 V; and wherein the process simultaneously produces hydrogen.

Description

ELECTROCATALYST FOR CONVERSION OF BIOMASS COMPONENT(S) INTO VALUE-ADDED CHEMICALS AND CONCURRENT GREEN HYDROGEN PRODUCTION FIELD OF THE INVENTION The present invention relates to a palladium-based electrocatalyst for the electrochemical oxidation of biomass component(s) into value-added products and green hydrogen production in a sustainable manner with long-term activity and that too without the generation of CO₂ gas. Particularly, the present invention also relates to a process for preparing said palladium-based electrocatalyst for the conversion of biomass components into value-added products. More particularly, the present invention relates to a process of production of the value-added product(s) (specifically all types of simple, branched, or cyclic C2-C3 acids or lactone acids) by reacting said biomass component(s) with said palladium-based electrocatalyst. BACKGROUND OF THE INVENTION Hydrogen is a vital feedstock for next-generation clean fuel and carbon-neutral economy. At present, 95% of H2 is produced from fossil fuels by steam reforming of methane/naphtha and coal gasification process. Energy and/or fuel derived from fossil fuels are neither sustainable nor eco-friendly, due to large emissions of CO₂. Water electrolysis provides an alternative pathway for the production of high- purity hydrogen, with minimum CO2. However, large electricity consumption remains a key challenge in conventional water electrolysis due to the high thermodynamic potential of 1.23 V for oxygen evolution reaction (OER). For example, the cost of hydrogen produced from electrolysis per kilogram ranges between US$5 and 12, depending on the production method. There is an urgent need to reduce the cost to around US$1-2/Kg for actual commercial production and utilization. Although various technological efforts are underway, it appears to be a significantly long way to reach the green hydrogen price target of US$ 2/kg through any electrolysis route, since the challenges are too many. The replacement of OER by a suitable organic oxidation, such as biomass derivative, is an effective strategy to reduce the cost of hydrogen. Furthermore, the oxidation of biomass derivatives, such as glucose, to produce value-added chemicals, can increase the efficiency and attractiveness of the whole process. In other words, instead of water oxidation to oxygen, biomass components get oxidized on the anode and water splitting to hydrogen occurs on the cathode; indeed, this becomes a carbon- negative way to produce hydrogen, which is indeed very attractive commercially. Therefore, glucose electrooxidation reaction (GLUOR) and glycerol electrooxidation reaction (GLYOR) can be coupled with hydrogen evolution reaction (HER) to accelerate hydrogen production at low over-potential (than water splitting) in the alkaline electrolyser. Although conventional organic electrolyser uses organic feeds, such as furfural, and 5-hydroxymethyl furfural (HMF), these are very useful platform chemicals or value-added chemicals used in many organic transformations. Moreover, the conversion of starch and/or cellulose to HMF and furfural with high selectivity and yield is itself an economically challenging process. Therefore, the decoupling of OER with GLUOR is particularly appealing for sustainable hydrogen production due to its availability and cost-effectiveness. The conversion is the most important descriptor to evaluate hydrogen formation in GLUOR and GLYOR or related processes. The higher the conversion, the more oxidation products will form with simultaneous acceleration in hydrogen generation at the cathode. However, the amount of hydrogen production in GLUOR and GLYOR or other related processes was quite low because of the less conversion at low overpotential. Therefore, rational catalyst design should consider possibly 100 % conversion of biomass components e.g. glycerol/glucose at lower potential and high current density (100 mA/cm² and above) is necessary to improve the hydrogen production and the simultaneous reduction in cost. In other words, compared to the potential required for OER, GLUOR/GLYOR- related processes should occur at a significantly lower potential to completely avoid OER. Reference may be made to the Journal “ACS Catal. 2021, 11, 14926-14931” which reports the GLYOR reaction with nanostructured gold fabricated on silicon and evaluates the overall effect of parameters such as reaction time and applied potential. However, the article shows the GLYOR performance of electrochemically reduced anodic treated gold coated on Ni-foam catalyst and reports 68.7% conversion at 1 V (vs RHE) in 2 hours; 41.2 % glycolic acid selectivity was observed, along with other five products, namely formic acid, lactic acid, tartronic acid, glyceric acid, and oxalic acid. Till date, this appears to be the best performance reported in the literature. Nonetheless, higher glycerol conversion at a relatively lower potential should be achieved with a current density higher than 100 mA/cm², which is also a great challenge, and the same is addressed in the current findings. Reference may be made to the Journal “ J. Am. Chem. Soc.2022, 144, 7224-7235” which discloses the development of CoNiCuMnMo alloy material for GLYOR and concurrent hydrogen production in electrolytic cell setup. This system delivered a current density of 10 mA/cm² at 1.25 V with high Faradaic efficiency for formate. Nonetheless, it needs to be highlighted that acidic condition (0.5 M H₂SO₄) was used for hydrogen production and therefore very difficult to scale up for industrial applications. Reference may be made to the journal “NatureCommun.2019, 10, 5335” which discloses the development of a nickel-molybdenum nitride catalyst for GLYOR and concurrent hydrogen production from alkaline glycerol. However, the electrolyser requires a minimum of 1.36 V to achieve 10 mA/cm²current density, which is significantly less for any industrial application. Although a high current density of 90 mA/cm² was reported, but at high potential of nearly 1.80 V. Reference may be made to the journal “NatureCommun.2020, 11, 265” which discloses the development of nickel-iron nitride catalyst for GLUOR and concurrent hydrogen production. A minimum cell potential of 1.39 V was required to achieve a current density of 100 mA/cm², which is a significantly higher potential to be useful in practical applications. Reference may be made to the journal “Chem. Eur. J. 2018, 24, 18258-18270” which discloses the oxidation of furfural, 5-Hydroxy methyl furfural (HMF), levulinic acid, glycerol, sorbitol (C6) etc. As glycerol oxidation, the catalyst Au, Pt, AuPt alloy and CO₃O₄-based catalysts were employed. There is no research on the shape and size of nanoparticles with glycerol or any other organic molecule oxidation has been reported. Reference may be made to the journal “ChemElectroChem2019, 6,13,3214-3226” which discloses the oxidation of alcohol, aldehyde, amines, hydrazine, glycerol, urea, etc. based system where the overpotential was decreasing with respect to water oxidation reaction with all the organic molecules. Another molecule 5- Hydroxymethyl furfural (HMF) which is produced by the degradation of C6- carbohydrate, performed similarly to other molecules; however, the high cost of raw materials, like HMF, makes it less economical to use them in any work. Indeed, the real challenge is in converting glucose, glycerol, cellulose, etc which are available at very cheap prices. Moreover, the reaction temperature reported in this article is between 50 and 80°C, and the same is not preferable at all as there are definite advantages in carrying out the reactions at ambient conditions (around 25 °C). Reference may be made to the journal “Adv. Energy. Mater.2021, 11, 2102292” which discloses co- electrolysis system associated with hydrogen evolution reaction (HER) paired with thermodynamically favorable oxidation reaction on the catalysis surface like urea, hydrazine, ammonia, alcohols, biomass-derived compounds (glycerol, glucose), organic compounds, and polyethylene terephthalate plastic etc. Here, Pd, PdCu alloy, Bi modified Pd and Pd/C-CeO₂ catalyst was used as mono-diol, glycerol oxidation. However, the current density reported is lower and the onset potential is significantly higher, which makes it less attractive. Present invention also includes nickel-molybdenum-nitride nanoplates loaded on carbon fiber cloth used as anode and cathode side for glycerol oxidation and reduction. For the combination of glycerol selective oxidation and HER, the overall cell potential 1.36 V was employed, which is 260 mV lower than that of overall water splitting. For glucose oxidation Ni, Fe and Co based system were discussed here, but with high oxidation onset potential for glucose oxidation. Reference may be made to the patent document US 2018/0023199 A1 which discloses Ni2P deposited over nickel foam and introduced HMF oxidation and the onset was 1.3 V vs RHE. However, the high cost of raw materials, like HMF, makes it less economical to use them in any work, especially at high applied potential. Indeed, the real challenge is in converting glucose, glycerol, cellulose etc. which are available at very cheap price at low applied potential with high current density. This stringent requirement needs the inherent property of the catalyst to be developed to operate at low potential with high current density, which is yet to be reported. Further, making a single type of catalyst site available all over the surface of the catalyst could make the same to produce highly selective products. Therefore, to overcome drawbacks in the prior arts, there is an urgent need for new rational catalysts and process development that will effectively improve the oxidation of biomass components at the anode and hydrogen activity at low applied potential with high current density. OBJECTIVES OF THE INVENTION Main objective of the present invention is to provide a palladium-based electrocatalyst for the electrochemical oxidation of biomass component(s) into value-added products and green hydrogen production in a sustainable manner, and that too without the generation of CO₂ gas. Another objective of the present invention relates to shape-dependent nano palladium electrocatalysts for biomass component(s) electro-oxidation in alkaline solution at very low applied potential to generate value-added chemicals and hydrogen. Yet another objective of the present invention is to provide a process of preparation of said palladium- based electrocatalysts for the conversion of biomass components into value-added products and H2. Still another objective of the present invention is to provide a process of production of value-added product(s) by reacting biomass component(s) (e.g. waste/biomass material containing monosaccharides, such as glucose or glycerol, etc.) with said palladium-based electrocatalysts. Still another objective of the present invention is to provide a process of production of the value- added product(s) by reacting biomass component(s) with said palladium-based electrocatalysts by achieving 100 % or near 100 % conversion of biomass component(s) with high current density (more than 100 mA/cm²) at low applied potential [less than 0.9 ^0.1 V (vs. RHE)]. Still another objective of the present invention is to provide a process of production of value-added chemicals from glucose and/or glycerol electro-oxidation with rationally designed Pd electrocatalysts. Yet another objective of the present invention is to provide a process of production of value-added chemicals by achieving 100 % or near 100 % conversion of glucose/glycerol with high current density (more than 100 mA/cm²) at low applied potential [less than 0.9 ^0.1 V (vs. RHE)]. Still another objective of the present invention is to provide a process of production of value-added chemicals along with green hydrogen production concurrently from the water reduction on the noble metal or non-noble cathode material with long-term performance. Still another objective of the present invention is to provide a process of production of value-added chemicals by preserving the atom economy aspect to near 100 % mass balance by preventing any runaway reaction to CO2. SUMMARY OF THE INVENTION Accordingly, present invention provides an electrocatalyst comprises palladium nanoparticles deposited onto a support; wherein said palladium nanoparticles is in the form selected from the group consisting of palladium nanocubes (Pd-NC), palladium truncated octahedron (Pd-TO) and polycrystalline palladium (Pd-PC) or mixtures thereof; the support used is selected from Ni foam or carbon paper. In an embodiment of the present invention, the particle size of palladium nanoparticle is in range of 4 to 8 nm. In another embodiment, the present invention provides a process of preparation of the electrocatalyst comprising the steps of: a) adding a surfactant, an ascorbic acid and a reagent in water under ultrasonication for a period in the range of 8 to 15 minutes followed by heating at temperature in the range of 75 to 85 °C with stirring to prepare the aqueous mixture; b) adding a palladium halide and KCl in a 1:2 mole ratio in the aqueous mixture as obtained in step a) at temperature in the range of 75 to 85 °C for time period in the range of 2 to 4 hrs to obtain the palladium nanoparticle form; and c) washing and drying the palladium nanoparticle forms as obtained in step b) to obtain pure palladium nanoparticle; provided that the reagent of step a) is either present or absent. In yet another embodiment of the present invention, the surfactant is selected from the group consisting of polyvinylpyrrolidone (PVP), cetyltrimethylammonium bromide, sodium dodecyl sulphate or combination thereof. In yet another embodiment of the present invention, the reagent in step a) is selected from potassium chloride (KCl) or citric acid. In yet another embodiment of the present invention, in case of preparation of Pd-NC form, the reagent of step a) is KCl; in case of Pd-TO, the reagent of step a) is citric acid; and in case of Pd-PC, the reagent of step a) is absent. In yet another embodiment of the present invention, the palladium halide is selected from palladium chloride, palladium bromide or combination thereof. In another embodiment, the present invention provides a process of preparation of an electrode using the electrocatalyst comprising steps of: i. uniformly dissolving the electrocatalyst in ethanol to obtain a catalyst ink; ii. drop casting the catalyst ink as obtained in step (i) onto a support over hot plate at temperature in the range of 55 to 75°C for a period in the range of 10 to 12 hr to obtain the electrode. In another embodiment, the present invention provides an electrochemical oxidation process of biomass component(s) into value added products and green hydrogen using the electrocatalyst comprising the steps of: a) mixing and dissolving biomass derived component(s) in potassium hydroxide or sodium hydroxide solution to obtain biomass derived component(s) solution; b) reacting the biomass derived component(s) solution with the electrocatalyst under electrochemical setup for time period ranging from 30 minutes to 5 hr to obtain value- added products and hydrogen; wherein the electrocatalyst is in the form of an electrode as prepared above. In yet another embodiment of the present invention, the value-added products are selected from simple, branched or cyclic C2-C4 acids or lactone acids or mixture thereof preferably gluconic acid, glucaric acid, along with some minor products, such as, glyceric acid, gluconolactone, glycolic acid, lactic acid, oxalic acid, acetic acid, formic acid or mixture thereof. In yet another embodiment of the present invention, the electrochemical setup comprises a graphite rod or Pt/C electrode as cathode material, and saturated calomel electrode (SCE) as reference electrode and a voltage applied is in range of 0.4 to 1.2 V. In yet another embodiment of the present invention, Ag/AgCl and Hg/HgO reference electrodes also provide comparable results. In yet another embodiment of the present invention, the electrocatalyst is in the form of electrode, preferably, in the form of anode. BRIEF DESCRIPTION OF THE DRAWINGS Fig 1 illustrates (a) Linear sweep voltammetry (LSV) results obtained for various shape-controlled Pd nanoparticles in 1 M KOH solution, without and with 0.1 M glycerol. Scan rate applied is at 20 mV/s. Chrono-amperometry studies carried out at different applied potentials for 4 hours with 0.1 M glycerol solution for (b) Pd-NC, (c) Pd-TO and (d) Pd-PC. Fig 2 illustrates Product selectivity observed as a function of applied potential for 0.1 M glycerol oxidation (GLYOR) with (a) Pd-NC (b) Pd-TO (c) Pd-PC anode catalyst, after 4 hours of reaction. No carbonate formation along with near 100 % selectivity of the products observed indicating the glycerol conversion only to value-added products. Fig 3 illustrates glycerol (0.1 M) conversion as a function of applied potential over different morphologies of Pd catalyst. While all the catalysts show near 100 % glycerol conversion at 1.2 V, Pd-TO and Pd-NC show near 100 % glycerol conversion even at 1.0 and 0.8 V (vs. RHE), respectively. Fig 4 illustrates (a) LSV profile of Pd-NC in the presence and absence of 0.1 M glucose in 1M KOH solution. A very similar LSV trend observed for Pd-TO and Pd-PC nanoparticles too. Although Pd- TO is somewhat better at low potential, 100 mA/cm² is observed at the same potential as Pd-TO and Pd-NC. (b) Chrono-amperometry data recorded at different applied potentials for 2 hours with glucose solution and Pd-NC. Fig 5 illustrates Glucose conversion (0.1 M) and selectivity of different value-added products obtained from GLUOR after a 2-hour reaction with a Pd-NC catalyst. Similar selectivity pattern was observed for Pd-TO and Pd-PC as well. Fig 6 illustrates ¹H NMR data of glycerol oxidation product at 0.9 V vs RHE. Fig 7 illustrates ¹H NMR data of glucose oxidation product at 0.6 V vs RHE. Fig 8 illustrates ¹H NMR data of glucose conversion and oxidation products at 0.6 V vs RHE for 4h of reaction. Fig 9 illustrates ¹H NMR data of gluconic acid, glucaric acid and glucose oxidation product distribution at 0.6 V vs RHE for 4h of reaction. Fig 10 illustrates the Electrochemical reaction setup employed for the glycerol and glucose oxidation (batch mode). Fig 11 illustrates LSV of GLYOR in 2 electrodes alkaline electrolyser with Pd-NC as anode and Pt/C as a cathode. Fig 12 illustrates Sustainable operation of the GLYOR process at 10 mA cm^-2 for 50 h. Fig 13 illustrates Sustainable operation of the GLYOR process at 50 mA cm^-2 for 10 h. Fig 14 illustrates the electricity/power consumed for hydrogen production in GLYOR and conventional alkaline electrolyzers. Fig 15 illustrates the LSV of GLUOR in 22-electrode alkaline electrolyser with Pd-NC as an anode, Pt/C and/or NiP as a cathode. Fig 16 illustrates Sustainable operation of the GLUOR process at 100 mA cm^-2 for 50 h in pure DI water. Fig 17 illustrates the Sustainable operation of the GLUOR process at 100 mA cm^-2 for 20 h in simulated seawater. Fig 18 illustrates the Electricity consumed for hydrogen production in GLUOR when Pt/C and NiP are used as cathode and Pd-NC as an anode in the electrolyzer. Fig 19 illustrates the HRTEM study of Pd-nanoparticles synthesized with different morphologies. Figures (a, d and g) TEM images of homogenously dispersed as-prepared Pd-NC, Pd-TO and Pd- PC, and corresponding high-resolution TEM images of Pd nanoparticles are given in b, e and h. Figures (c, f and i) display selected-area-electron diffraction (SAED) patterns of an individual Pd- NC, Pd-TO and Pd-PC. Fig 20 illustrates AFM topography and line profile analysis of (a-b) Pd-NC, (c-d) Pd-TO, and (e-f) Pd-PC. (g)KPM surface potential at different applied biases shows that Pd-NC has higher surface potential than Pd-TO and Pd-PC. DETAILED DESCRIPTION OF THE INVENTION The term “Monosaccharides” used herein refers to simple sugars with the most basic units (monomers) from which all carbohydrates are built. Examples of monosaccharides include but are not limited to glucose (dextrose), fructose (levulose), and galactose. Monosaccharides are the building blocks of disaccharides (such as sucrose and lactose) and polysaccharides (such as cellulose and starch). The present invention relates to an electrocatalyst for electrochemical oxidation of biomass component(s) into value-added products and green hydrogen production. The electrocatalyst comprises palladium nanoparticles deposited onto a support, wherein said palladium nanoparticles is in the form selected from palladium nanocubes (Pd-NC), palladium truncated octahedron (Pd-TO) and polycrystalline palladium (Pd-PC) or mixtures thereof. The particle size of palladium nanoparticle forms in the electrocatalyst is in range of 4 to 8 nm. The support used in the electrocatalyst is Ni foam or carbon paper. The electrocatalyst is in the form of electrode, preferably in the form of anode. The present invention further relates to a process of preparation of said electrocatalyst by a solvothermal method, the process comprising the following steps: a) adding a predetermined amount of a surfactant, ascorbic acid, and a reagent in water under ultrasonication for 8 to 15 minutes followed by heating at temperature in the range of 75 to 85 °C to prepare the aqueous mixture; b) adding a palladium halide in aqueous mixture of step a) at temperature in the range of 75 to 85 °C for time period of 2 to 4 hrs to obtain the palladium nanoparticle form; and c) optionally washing and purifying the palladium nanoparticle forms of step b) to obtain pure palladium nanoparticle form (Pd-NC, Pd-TO or Pd-PC); provided that the reagent of step a) is either present or absent. The surfactant is selected from polyvinylpyrrolidone, cetyltrimethylammonium bromide, sodium dodecyl sulphate and combinations thereof. The reagent in step a) is selected from potassium chloride (KCl) or citric acid. In case of preparation of Pd-NC form, the reagent is KCl; in case of Pd-TO, the reagent of step a) is citric acid; and in case of Pd-PC, the reagent is absent. The palladium halide is selected from palladium chloride, palladium bromide and combination thereof. The amount of surfactant used in step a) is in range of 25 to 150 mg; the amount of ascorbic acid is in range of 40 to 100 mg and the amount of reagent is in range of 100 to 300 mg. The amount of palladium halide is in range of 50 to 150 mg. The mole ratio of palladium halide and reagent is 1:2. The present invention further relates to a process of preparation of an electrode using the electrocatalyst, the process comprising the steps of: i. preparing a catalyst ink by uniformly dissolving said electrocatalyst in ethanol; ii. drop casting the catalyst ink onto a support over hot plate at temperature of 55 to 75 °C to obtain the electrode. The present invention relates to a process of production of value-added products, wherein the process comprises of: 1) reacting the solution of biomass derived component(s) with said electrocatalyst under electrochemical setup for time period ranging from 30 minutes to 5 hrs. The value-added products are selected from simple, branched or cyclic C2-C4 acids or lactone acids, or mixture thereof. Specifically, the value-added products are selected predominantly from gluconic acid, glucaric acid, along with some minor products, such as, glyceric acid, gluconolactone, glycolic acid, lactic acid, oxalic acid, acetic acid, formic acid, or mixture thereof. The biomass derived component(s) solution is prepared by mixing and dissolving biomass derived component(s) in potassium hydroxide or sodium hydroxide solution. The amount or concentration of biomass component(s) is in range of 0.05 to 1.5 M. Specifically, the concentration of biomass component(s) is 0.1 M. The biomass component(s) is/are selected from monosaccharaides, or mixture thereof. Preferably, the biomass component(s) is/are selected from glucose, glycerol, fructose, galactose, and so on. The concentration of KOH solution is in the range of 0.5 to 1.5 M. Specifically, the concentration of KOH solution is 1 M. The electrocatalyst is in the form of an electrode as prepared by the aforesaid process. The electrochemical setup comprises a voltage applied for oxidation is in range of 0.4 to 1.2 V; and the voltage applied for oxidation of biomass derived component(s) is preferably in range of 0.4 to 1 V or 0.6 to 1.2 V. The electrochemical setup further comprises a graphite rod or Pt/C electrode as cathode material, and saturated calomel electrode (SCE) as reference electrode. Ag/AgCl and Hg/HgO reference electrodes also provide comparable results. The process simultaneously produces hydrogen. The conversion of biomass component(s) into value added products is in range of 70-100 % for any of the three Pd catalysts. Specifically, the conversion of biomass component(s) into value added products is about 85 to 100% in case of Pd-NC, about 75-100% conversion in case of Pd-TO, and about 70-98% conversion in case of Pd-PC. The Pd-NC electrocatalyst deposited on a Ni foam achieved a highly impressive glycerol conversion of 85% at an exceptionally low applied potential of 0.6 V (vs RHE) in 0.5 M glycerol in 1M KOH solution. In contrast, Pd-TO and Pd-PC exhibited 70-75% conversion at similar conditions demonstrating the high intrinsic activity of (100) facets present on Pd-NC for GLYOR compared to the other two morphologies of Pd catalysts. The selectivity of production of said value-added products from biomass component(s) is in the range of 70-100 % for any of the three Pd-based catalysts. the total yield of said value-added products is in the range of 70-100 % The oxidation process of biomass component(s) provides a mixture of value-added products i.e., at least two or more value-added products in one go reaction. The process may be done in batch as well as continuous mode to obtain value-added products and H2. The present invention relates to the evaluation of the various-shaped Pd NPs (Pd-NC, Pd-TO, Pd-PC) for the glucose electrooxidation reaction (GLUOR) and glycerol electrooxidation reaction (GLYOR) activity. It is to be noted that the arrangements of Pd-atoms are different on the different facets of the catalyst surface. Pd-NC exhibits only (100) facets, while Pd-TO exhibits (100) and (111) facets together. Pd- PC is spherical in nature and shows a mixture of several facets (as explained above), which is typical for polycrystalline materials. Pd-PC contains many different facets, including (100) and (111). Availability of only one or two type of facet induces activity and selectivity very efficiently, while more than two facets reduce the selectivity significantly. Arrangement of Pd-atoms in said palladium nanoparticle form (Pd-NC, Pd-TO and Pd-PC) is same or variable depending on presence of one or more facet(s); wherein the one or more facets are selected from Pd (100), Pd(111) or mixtures thereof. The surface potential of said palladium nanoparticle form in said electrocatalyst is in range of 49-70 mV. Only the intrinsically high electrocatalytic activity surface exhibits high potential. High surface potential can be directly correlated to high surface charges, indicating the readiness to react with reactants. Pd-TO and Pd-PC exhibits surface potential values of 20-25 mV and 10-16 mV, respectively. Synthetic methodology adopted in the present findings leads to high surface potential values, which is no observed or reported earlier in any work. This is also the first work to correlate surface potential with electrochemical activity. Figure 1 shows the linear sweep voltammetry (LSV) results of various Pd nanostructures with different geometric current densities. In the absence of glycerol, the Pd-NC anode drives the OER (from water splitting) and exhibits a significantly high overpotential of 1.5 V at a current density of 50 mA/cm². In the presence of glycerol, the onset of GLYOR decreases very significantly to the low potential for all three morphologies of the Pd catalyst anode evaluated (Fig 1a). Importantly, Pd-NC shows the highest current density even at the low applied range. The catalytic current density of 100 mA/cm² was observed at a low applied potential of 0.8 V; to the best of the inventor’s knowledge, this is the best GLYOR geometric current density reported for any Pd-based catalyst. In contrast, Pd- PC exhibits lower GLYOR current density among all the three morphologies of Pd evaluated. Moreover, Pd-NC shows the lowest onset potential of 0.4 V and Pd-TO and Pd-PC exhibit an onset of 0.5 V. The chronoamperometry results revealed that the current density of the GLYOR continuously declined as the reaction proceeded and came to as low as 2-3 mA/cm². The rate of decrease of current density is significantly higher in the case of Pd-NC again suggesting a faster kinetics at low overpotential. The decrease in catalytic current in all three shapes is mainly due to the depletion of the glycerol concentration. Nevertheless, various products formed, such as formic acid, glyceric acid, and glycolic acid, exist in the form of acetate by consuming OH- ion. It is observed that a pH of 12.5, after 4 hours of GLYOR reaction, as compared to 13.5 at the beginning of the reaction; is also a reason for a small decrease in the current density. However, the slight change in solution pH did not decrease the catalytic current significantly as seen in Figure 1. The GLYOR activity on different morphology of Pd NPs was evaluated by chronoamperometry measurement as a function of applied potential in 1 M KOH and 0.1 M glycerol. Figure 2a shows the GLYOR selectivity at potential ranging from 0.6 to 1.2 V vs RHE with the three morphologies of Pd nanoparticles. All the chronoamperometry measurements were carried out for 4 h. At the lowest potential of 0.6 V vs RHE, glyceric acid was observed as the major product along with glycolic acid, lactic acid, oxalic acid and formic acid as the minor products. Notably, no appreciable change in product distribution was observed from GLYOR with different morphologies of Pd nanoparticles. At 0.6 V a maximum selectivity of ~ 61% was observed for combined C3 products (glyceric acid + lactic acid) formation with Pd-NC. When the potential increased to 1.2 V, the C2 products combined selectivity (glycolic acid + oxalic acid + acetic acid) was observed to be 48%; this indicates that high over-potential is required for the oxidative cleavage of the C–C bond. The selectivity towards glycolic acid started to enhance at 1.0 V vs RHE with all of the Pd nanoparticle morphologies. The formation of glycolic acid originated from the oxidative C–C bond cleavage of glyceric acid with simultaneous production of formic acid. Therefore, at potential ≥ 1 V formic acid production enhanced with increases in the total amount of C2 product formed. Similarly, lactic acid undergoes oxidative C-C cleavage from 0.8 V and above to glyceric and formic acids. The concurrent changes observed in the decrease in selectivity of C3 product molecules (glyceric acid + lactic acid) to the increase in selectivity of glycolic and formic acids reiterate the controlled C-C cleavage progressively. Nonetheless, critically, no carbonate peak in thr ¹³C NMR spectrum was observed even at the highest applied potential of 1.2 V vs RHE. This indicates that no runaway reaction of any value- added product to carbon dioxide was taking place during the GLYOR process in the potential range between 0.6 to 1.2 V vs RHE. In the GLYOR process, it is likely that some of the glycolic acid could get further oxidized to oxalic acid. Therefore, less than 5% of oxalic acid was observed throughout the potential range with any of the morphologies of Pd. The electron-withdrawing effect of the – COOH group in glycolic acid restricts the further oxidation of carbon atom containing a hydroxyl group. Lactic acid could form directly from either glycerol or the reduction of glyceric acid, which occurs at a low applied potential (0.6 V) without the cleavage of any C–C bond. The selectivity of lactic acid decreases with increased applied potential due to its oxidation to formic acid and acetic acid. Observation of a small and constant amount of acetic acid in the entire applied potential window supports this. Finally, the GLYOR process could eventually stop at the stage of formic acid and oxalic acid, as a higher potential is required to oxidize formic acid and convert it to CO2. Although the selectivity of different products is nearly independent of the shape of Pd, but the 0.1 M glycerol conversion is significantly different with different morphologies of Pd at a given applied potential (Fig 3). For instance, Pd-NC exhibited 85% conversion of glycerol after 4 h of reaction time at a significantly low applied potential of 0. 6V compared to 72% and 74% in Pd-PC and Pd-TO, respectively, under similar experimental conditions. The GLYOR process catalyzed by Pd-NC shows 100% conversion at 0.8 V and above. However, Pd-TO and Pd-PC exhibited near 100% glycerol conversion at a potential of 1 V and 1.2 V, respectively. This indicates that the rate of partial oxidation of glycerol is high on (100) facets of Pd-NC, compared to a mixture of (100) and (111) facets present on Pd-TO and Pd-PC. A comparison of the GLYOR conversion activity of different Pd-catalysts in an alkaline solution is shown in Fig 3. Pd-NC shows the highest glycerol conversion at the lowest overpotential among all the reported catalysts and directly demonstrates the inventive aspect of the current findings. Further, Pd-NC was extensively employed to investigate the electrochemical performance of anodic glucose oxidation reaction (GLUOR) and cathodic HER. Pd-NC shows high selectivity toward gluconolactone and near 100% conversion to value-added products was observed at a potential of 0.4 V RHE. This is probably the best active catalyst reported, so far, for electrocatalytic GLUOR at the lowest overpotential. The LSV profile of GLUOR and OER with Pd-NC electrocatalyst in 1 M KOH solution is shown in Fig 4a. With 0.1 M glucose, a mere 650 mV is required to reach a catalytic current density of 100 mA/cm². In fact, the current density observed above is significantly higher than that with the 0.1 M glycerol solution, shown in Fig 1a with Pd-NC. It is also to be underscored that glucose is a C6 molecule, while glycerol is C3 molecule. In contrast, OER required 1.77 V to reach the same 100 mA/cm²current density on Pd-NC catalyst due to the sluggish kinetic of the four-electron process. Such significant reduction in anodic potential is highly beneficial for hydrogen production with low electricity utilization. Feature observed at 1.5 V during OER is because of oxidation of metallic Ni. Fig 4b shows chronoamperometry for GLUOR at different applied potential. Interestingly, glucose oxidation with Pd-TO and Pd-PC also shows very similar LSV results, as that of Pd-NC, with 0.1 M glucose in 1 M KOH solution. The product analysis was carried out after each chronoamperometry experiment and the results are shown in Fig 5. Even at the lowest potential of 0.4 V a ~90 % selectivity for gluconolactone was observed with 100 % glucose conversion in two hours of reaction. When the applied potential was 0.6 and 0.7 V, it is observed that around ~10-15 % selectivity for lactic acid and around 5% of formic acid was produced in the entire potential range. Another important contrast was observed with glucose and glycerol conversion activity onset at 0.4 and 0.6 V, with 100 % glucose or 85 % glycerol conversion, respectively. The different products obtained in glycerol and glucose oxidation are shown in the ¹H NMR spectra (Fig 6 and 7) at 0.9 V and 0.6 V vs RHE respectively (the inset figure shows ¹H NMR spectra of pure glycerol and glucose). Fig 8 demonstrates a systematic decrease in glucose signal intensity as the reaction proceeds (1h, 2h) and completely disappears at 4h; this confirms 100% conversion of glucose to value-added products. Products generated from glucose oxidation are characterized by ¹H &2D NMR (Total correlation spectroscopy -TOCSY) and the results are shown in Fig 9. Selective excitation and TOCSY transfer with a sample generated after a 4 h reaction confirms the formation of gluconic and glucaric acid products. It is observed that around ~60-70 % selectivity for gluconic acid and around 30-40 % of glucaric acid was produced in the entire potential range. A schematic of the batch reactor is shown in Fig 10 and consists of a working electrode (WE), a reference electrode (RE) and a counter electrode (CE). The GLYOR and GLUOR activity of Pd-NC and the concurrent HER performance were further evaluated in a two-electrode electrolyser. An anion exchange membrane was placed between the anode and the cathode to stop the crossover of the products to other sides. In the case of GLYOR, the electrolyser was fitted with Pt/C as the cathode and Pd-NC remained the anode (or working electrode). Fig 11 presents the LSV curve for GLYOR in the alkaline electrolyser. It requires a voltage of 1.5 V to achieve 100 mA/cm². However, no OER (oxygen evolution reaction) current was observed at 1.5 V when the experiment was carried out without glycerol. Even with 0.34 M NaCl solution (equal to sea-water NaCl content), the chlorine oxidation reaction is fully avoided and a marginal decrease in GLYOR current was observed. To investigate the stability of the Pd-NC catalyst in two electrodes alkaline electrolyser, a chronopotentiometry experiment for 50 h was conducted at 10 mA/cm² current density (Fig 12). The voltage remains constant at ~0.8 V throughout the 50 h operation and it shows high stability of the catalyst. The sustainable operation of the catalyst in the electrolyser with 0.34 M NaCl solution at 10 mA/cm²current density was also carried out and observed a marginal increase in operating potential to ~0.1 V. The electrolyser continuously produced hydrogen at a rate of 0.71 mmol/h over 50 h. Moreover, we have also carried out a stability test of the Pd-NC catalyst at 50 mA/cm² current density for 10 h (Fig 13). It can steadily work at 1.1 V and produce hydrogen at a rate of 1.1 mmol/h over 10 h. Accordingly, a GLYOR based hydrogen production system requires electricity input of only ~3.7 kWh/Nm³ of H₂ at a current density of 100 mA/cm²(Fig 14). However, conventional electrolysers (alkaline or PEM) require ~5 kWh/Nm³ of H2 with relevant current density. Furthermore, to achieve a current density of 50 mA/cm², it requires input electricity of only 1.13 kWh/Nm³ of H₂ which is even less than the theoretical value of 2.94 for water splitting reaction at 1.23 V. For GLUOR, the electrolyser was assembled with Pt/C and/or nickel phosphide (NiP) as the cathode and Pd-NC remained as the anode. Fig 15 presents the LSV curve for GLUOR in the alkaline electrolyser. It shows that 100 mA/cm² current density was achieved at an applied voltage of 1.4 and 1 V volts when NiP and Pt/C were used as cathode, respectively. Like GLYOR, no OER current was observed at 1.4 and 1 V when the experiment was carried out without glucose with NiP and Pt/C, respectively. A chronopotentiometry experiment for 50 h was conducted at 100 mA/cm² current density to study the long-term operation of the electrolyser with both NiP and Pt/C used as the cathode (Fig 16). Even with 0.34 M NaCl chlorine oxidation reaction is fully avoided and a marginal decrease in GLUOR current was observed. The voltage remains constant throughout the 50 h operation as shown in Figure 16 with both NiP and Pt/C being used as cathode. The electrolyser continuously produced hydrogen at a rate of 200 mL/h over 50 h. Moreover, we have also carried out the stability test of the Pd-NC catalyst at 100 mA/cm² current density with NaCl solution for 20h (Fig 17). No change in cell voltage was observed and chlorine oxidation was fully avoided during GLUOR. This further suggests a wider opportunity for chlorine-free sea water splitting coupled with GLUOR. An electricity input of only ~3.35 kWh per m³ of H₂ was required at a current density of 100 mA/cm² (Fig 18) when NiP was used as a cathode. In contrast, the Pt/C cathode exhibited an electricity input of only ~2.39 kWh per m³ of H₂ to achieve a current density of 100 mA/cm². These results underscore the use of earth-abundant catalysts for the long-term operation of electrolysers with improved techno-economical performances. Fig 19 shows the HRTEM study of Pd-nanoparticles synthesized with different morphologies. Fig 19a shows the Pd-NC nanoparticles synthesized using KCl as a capping agent and are in the size range of 8-10 nm. The measured d-spacing is found to be 0.19 nm and it corresponds to the interplanar spacing of (200) facet of the face-centered cubic (fcc) lattice (Fig 19b). The corresponding SAED patterns of Figure 19b is shown in Fig 19c representing that the Pd-NC was a single nanocrystal with (200) facets. Fig 19d shows the TEM image of Pd-TO nanoparticles with a uniform TO morphology with a 7-10 nm particle size range. The lattice d-spacing of Pd-TO is 0.22 nm and it corresponds to the (111) facets of Pd (Fig 19e). The corresponding SAED pattern was recorded and shown in Fig 19f, which represents that the Pd-TO was a single nanocrystal. Pd-TO exhibits (111) as the dominant facet along with (200) facet too. Fig 19g shows the TEM image of Pd-PC nanoparticles with uniform spherical particles of 3-5 nm size. HRTEM image of Pd-PC is shown in Fig 19h and the corresponding SAED pattern (Fig 19i) represents the polycrystalline nature of the NPs due to the presence of various facets including (110), (111), and (100). All the Pd nanostructures were drop cast on a Ni-foam and used for electrochemical measurements. Fig 20 shows AFM topography and line profile analysis of (a-b) Pd-NC, (c-d) Pd-TO, and (e-f) Pd- PC. (g) KPM surface potential at different applied biases shows that Pd-NC has higher surface potential than Pd-TO and Pd-PC.Pd-NC and Pd-TO NPs show typical AFM topography images and corresponding surface potential (Fig 20a-d). However, Pd-PC NPs show a triangular shape with a non-uniform surface structure (Fig 20e-f). Significant agglomeration was likely due to the polycrystalline nature of the particles. Compared to Pd-TO and Pd-PC, the surface potential is higher with Pd-NC (Fig 20g). (100) facet is known to be unsaturated and exhibit open structure, then (111) or (110), and the same is attributed to high surface charge on Pd-NC. It is also ruled out for any artifacts that might arise due to line-by-line fitting by repeating the set of experiments for several cycles as well as on different batch materials, and reproducible surface potential values were observed. It is evident from the line profile analysis that the edges of the NPs exhibited higher surface potential. Moreover, the diffusion of subsurface oxygen in (100) facets is relatively higher compared to (111) and (110) facets, as (100) facets are lower in Pd atomic density. EXAMPLES The following examples are given as a way of illustration only and should not be construed to limit the scope of the present invention. Materials Potassium tetrachloride palladate (K2PdCl4), Palladium (II) chloride (PdCl2), polyvinylpyrolidine (PVP) with average molecular weight of 40 000, and ascorbic acid were procured from Sigma- Aldrich. Potassium bromide (KBr), Potassium chloride (KCl), citric acid, acetone, ethanol, methanol and n-hexane were purchased from Merck. All the precursors, solvents, and other compounds were used as received. Example 1: General Synthetic process of Pd Nanocubes nanoparticles The solution phase method was adopted for the synthesis of 4-8 nm size of Pd nanoparticles. In 8 mL water, 25-150 mg PVP, 40-100 mg ascorbic acid, and 100-300 mg of KCl were added in a 25 mL capacity 3-neck round-bottom flask (RBF). The flask was sonicated for 10 minutes to ensure that all the ingredients were completely dissolved and then heated to 75-85 °C under constant stirring in an inert atmosphere. A total of 50–150 mg containing PdCl2 and KCl in a 1:2 mole ratio, in aqueous solution (in 2-6 ml) was added to the aforementioned solution. Subsequently, 5–10 min was allowed to maintain at the same temperature (75–85 °C), and subsequently for three hours under constant stirring. After 3 h, the Pd-nanoparticle solution obtained was cooled to room temperature and collected in centrifuge bottles. Washing or cleaning of the nanoparticles was carried out by centrifuging the solution with the excess amount of acetone 1 time and ethanol: hexane mixture (1:5 ratio) at 10000 rpm 5 times. The final precipitate was dried in the oven at 60 °C and then used for catalytic reaction. The synthesized Pd nanocubes were characterized by HRETM and AFM Figure 19 and 20 AFM studies show that the average surface potential for Pd-NC is 49 mV which is higher than the other two morphologies, Pd-TO and Pd-PC. Example 2: Synthesis of Pd truncated octahedra nanoparticles The synthesis of the Pd truncated octahedron (Pd-TO) with dominant (111) facet along with (100) facet is synthesized by following the same preparation procedure given in Example 1, except for the use of 100-300 mg citric acid, instead of KCl. Example 3: Synthesis of Pd polycrystalline nanoparticles Synthesis of Pd polycrystalline followed the same procedure as that of example 1 or 2, but without employing any KCl or citric acid. Example 4: Fabrication of working electrode All the electrodes were prepared by the drop-casting coating method. Pd nanoparticle anode Initially Ni foam was cleaned with 1 M HCl for 30 min ultrasonication bath, and washed with DI water and ethanol consecutively for 10 min in sonication bath, followed by vacuum drying at 70 °C for 10 h.3 mg Pd nanocatalyst was dispersed in 3 ml IPA and drop casting slowly over the (1*1 cm²) Ni foam substrate and dried in a vacuum oven for 12 h. In the electrolyser, the Pd-NC electrode was prepared by a spray coating method and the catalyst loading amount was approximately 1 mg cm^-2. Pt/C cathode: 20% Pt/C standard catalyst was used as cathode part for HER reaction, by spray coating method; the amount of catalyst was approximately 0.8 mg.cm^-2. Example 5: Geometrical area of the substrate for the electrocatalytic reaction For the 1cm² area electrode, a 1*3cm² Ni foam substrate area is employed/ used. Aside from the 1 cm² region, the remaining area was covered with PTFE tape for the non-conducting side. This Ni foam substrate was fixed by low resistance copper wire.For Ni-substrate cleaning, 3M HCl was employed for 30 minutes under sonication; this is followed by multiple rinsing with deionized water and final wash with ethanol or isopropyl alcohol. After that it was dried for 12 h at 60-70 °C under vacuum. Example 6: Optimization of catalyst amount The glycerol and glucose oxidation reaction are feasible with any morphology of Pd. On a pre-cleaned Ni foam substrate, a known amount (2-4 mg Pd) of aqueous homogeneously dispersed Pd nanoparticles was drop-casted and dried for 12 hours. The thin films were examined in a three- electrode electrochemical setup with a graphite rod (or Pt/C) functioning as the counter electrode and a saturated calomel electrode (SCE) functioning as the reference electrode in the presence of an aqueous solution of KOH with glycerol or glucose. Example 7: Electrocatalytic reaction condition for glycerol oxidation to value added products Three-electrode system within one container is used for glycerol oxidation reaction, with any one morphology of Pd nanoparticles coated over Ni foam functioning as working electrode; Saturated calomel electrode (SCE) and graphite rod (or Pt/C) was functioning as reference and counter electrodes respectively. The reaction was carried out in 10-15ml of solution (1M KOH+0.1M glycerol). The reactions were conducted from 0.6V (vs. RHE) and above. Example 8: Electrocatalytic reaction condition for glucose oxidation to value added products A three-electrode system within one container is used for glycerol oxidation reaction, with any one morphology of Pd nanoparticles coated over Ni foam functioning as the working electrode; Saturated calomel electrode (SCE) and graphite rod was functioning as the reference and counter electrodes, respectively. The reaction was carried out in 7 ml of solution (1 M KOH + 0.1 M glucose). The reactions were conducted from 0.4 V (vs. RHE) and above. Example 9: Identification of liquids product After the reaction, the liquid product was collected and examined by proton nuclear magnetic resonance (¹H NMR) (AV-NEO 400 & 500, BrukerBioSpin AG; Magnet system 400-500 MHz), available at NCL, Pune, MH, India. Glyceric acid, glycolic acid, lactic acid, acetic acid, and formic acid are the products of glycerol oxidation were observed (refer, figure 6, NMR data confirming these products) and confirmed. A minute amount oxalic acid was observed and estimated from the high- performance liquid chromatography (HPLC). The products formation was further confirmed by comparing with the experimental data to standard sample data of pure components. In the case of glucose oxidation, gluconolactone, lactic acid, and formic acid were observed as products (see, figure 7, NMR data confirming the products), with gluconolactone as the major product observed at the lowest potential. The NMR comparison of the standard sample confirmed all products. Example 10: Confirmation of no run away reaction and/or no carbonate in the reaction product mixture Any runaway reaction, such as formic acid oxidation, is expected to produce CO₂, which can be identified as a carbonate species in the basic electrolyte solution. For carbonate confirmation, ¹³C NMR methodology was accomplished; no carbonate peak was observed at 160 ppm for any oxidation reactions carried out in the present case. Example 11: Preparation of NMR sample 600 µl of total standard volume was poured in an NMR tube for the ¹H NMR anlaysis; whereas 450 µl of reaction mixture, 130 µl of D₂O, and 20 µl of internal standard (1 mM) was used to quantify all the products. Example 12: Identification of gaseous product on graphite electrode In an electrochemical reaction system, cathode part electrode executes reduction reaction, while another side anode part executes oxidation process. H₂ bubbles were seen emerging from the cathode, which is identified and confirmed by Agilent Gas Chromatograph. Quantification of the amount of H2by inverted burette method is also done. At 1.2 V vs RHE, Pd-TO produced 60 mL of hydrogen at the graphite electrode during 4 hours of glycerol electrooxidation. Similarly, Pd-TO produced 30 mL of hydrogen at 0.7 V vs RHE during 2 hours of glucose electrooxidation. Example 13: Quantification of liquid product For quantification of the liquid product, ¹H NMR technique was used and KHP (Potassium Hydrogen Phthalate) was employed as an internal standard for quantification of all the products observed in NMR results. The concentration of liquid products formed after the electrocatalytic reaction was calculated by using the following formula:

Here, n_x represents the molar concentration of KHP, I_x represents the integral area in ¹H NMR spectra for KHP, and N_x is the number of nuclei (4 equivalent protons for KHP appearing at 7.25 ppm). Similarly, ny is calculated from the above formula for the liquid product, Iy integral area of the product formed, and N_y is the number of nuclei associated with the peak. Example 14: Oxygen evolution reaction The reaction measurements, as mentioned in examples 7 or 8 was conducted, but without the addition of glucose or glycerol. This is to measure the water splitting and to measure the OER characteristics. Example 15: Pt/C HER catalyst and quantification of evolved gas Modification of HER catalyst is done since rate of hydrogen evolution in the graphite rod was slow. In the place of graphite rod, commercially available Pt/C catalyst is employed and measured amount of hydrogen during GLYOR and GLUOR. GC analysis of gaseous product shows that only H₂ was evolved from the cathodic side and therefore amount of H₂is quantified by inverted burette method. Example 16: Electrolyzer setup for GLYOR and GLUOR Due to the low efficiency of the graphite electrode, both reactions in the electrolyzer were carried out using continuous flow method with Pt/C or Nickel phosphide (NiP) acting as cathode. Spray coating method with N2 gas pressure at 10 psi was used to prepare Pd-NC catalyst on Ni foam for glycerol oxidation, and Pt/C (20 wt% Pt, and remaining is C) catalyst on Ni foam for HER. A sustainion membrane functioned as separator was employed between two compartments of electrolyzer and as an anion exchange medium for the electrolyte. Pure DI (de-ionized) water and simulated sea water were tested for 50 hours each of continuous stability (a total of 100 h) at 10 mA cm^-2for glycerol oxidation to demonstrate sustainable performance with long-term activity.10-hour stability test was conducted in DI water and simulated sea water to evaluate performance at higher current density, 50 mA cm^-2. The collected H₂ was quantified using inverted burette method, and electrolyte flow rate was maintained at 4-5 ml/min. Identical Pd-NC/NF catalyst was employed in all trials without affecting electrolyzer, and there was no oxygen evolution reaction (OER) observed. Pd-NC/NF was employed for glucose oxidation; while NiP, an earth abundant catalyst was used for HER. The electrodeposition method was used to prepare NiP electrode. NiP is electrodeposited in a controlled manner over the Ni foam; nickel chloride and sodium hypophosphite were used as precursors in an aqueous solution to prepare NiP. The best-performing electrode was then employed as an alternative HER catalyst in place of 20 wt % Pt/C, and the optimization carried out at -0.75 V to -1.0 V vs. SCE for 10 to 30 min using a various electrode. Since glucose oxidation is more efficient than glycerol oxidation, GLUOR was evaluated at higher current density, 100 mA/cm², for stability, and there is no oxygen evolution reaction (OER) was observed. The catalysts NiP/NF and Pd-NC/NF were assembled in a (2*2) cm² area of electrolyzer setup, and the anion exchange from the electrolyte was facilitated by a sustainion membrane. It is also critical to note that the anodic catalyst Pd-NC/NF was stable during the entire 140-h reaction with no OER occurring. The electrolyte flow rate was kept at 15-20 ml/min by using a peristatic pump. ADVANTAGES OF THE INVENTION The present invention provides a cost-effective way to produces clean and green hydrogen. Simple drop casting method employed for electrode fabrication. Shape controlled Pd electrocatalyst oxidised glycerol and glucose at lower potential. The present invention provides a cost-effective way to produce valuable chemical like formic acid, glycolic acid, glyceric acid, lactic acid, gluconolactone, gluconic acid, glucaric acid, etc. The Pd catalyst is highly stable for several days. This invention provides energy saving (due to requirement of lower voltage E than known ones – 0.4 to 1.2 vs 1.4 or more), Higher scalability (32-60% less E requirement), no CO₂ production with sustainable activity, and complete conversion of reactants into products or mixture of products i.e., conversion rate of 100%along with selectivity and yield upto 98%.

Claims

We Claim 1. An electrocatalyst comprising palladium nanoparticles deposited onto a support; wherein said palladium nanoparticles are selected from the group consisting of palladium nanocubes (Pd-NC), palladium truncated octahedron (Pd-TO) and polycrystalline palladium (Pd-PC) or mixtures thereof; wherein the support used is selected from Ni foam or carbon paper. 2. The electrocatalyst as claimed in claim 1, wherein the palladium nanoparticle is having the particle size in the range of 4 to 8 nm. 3. A process of preparation of the electrocatalyst as claimed in claim 1 comprising the steps of: a) adding a surfactant, an ascorbic acid and a reagent in water under ultrasonication for a period in the range of 8 to 15 minutes followed by heating at temperature in the range of 75 to 85 °C with stirring to obtain an aqueous mixture; b) adding palladium halide and KCl in a 1:2 mole ratio in the aqueous mixture as obtained in step a) at temperature in the range of 75 to 85 °C for time period in the range of 2 to 4 hrs to obtain the palladium nanoparticle form; and c) washing and drying the palladium nanoparticle forms as obtained in step b) to obtain pure palladium nanoparticle; provided that the reagent of step a) is either present or absent. 4. The process as claimed in claim 3, wherein the surfactant is selected from the group consisting of polyvinylpyrrolidone (PVP), cetyltrimethylammonium bromide, sodium dodecyl sulphate or combination thereof. 5. The process as claimed in claim 3, wherein the reagent in step a) is selected from potassium chloride (KCl) or citric acid. 6. The process as claimed in claim 3, wherein the palladium halide is selected from palladium chloride, palladium bromide or combination thereof. 7. A process of preparation of an electrode using the electrocatalyst as claimed in claim 1 comprising steps of: i. uniformly dissolving the electrocatalyst as claimed in claim 1 in ethanol to obtain a catalyst ink; ii. drop casting the catalyst ink as obtained in step (i) onto a support over hot plate at temperature in the range of 55 to 75°C for a period in the range of 10 to 12 hr to obtain the electrode. 8. An electrochemical oxidation process of biomass component(s) into value added products and green hydrogen using the electrocatalyst as claimed in claim 1 comprising the steps of: a) mixing and dissolving biomass derived component(s) in potassium hydroxide or sodium hydroxide solution to obtain biomass derived component(s) solution; b) reacting the biomass derived component(s) solution as obtained in step a) with the electrocatalyst of claim 1 under electrochemical setup for time period ranging from 30 minutes to 5 hr to obtain value-added products and hydrogen; wherein the electrocatalyst is in the form of an electrode as prepared in claim 7. 9. The electrochemical oxidation process as claimed in claim 1, wherein the value-added products are selected from simple, branched or cyclic C2-C4 acids or lactone acids or mixture thereof preferably gluconic acid, glucaric acid, along with some minor products, such as, glyceric acid, gluconolactone, glycolic acid, lactic acid, oxalic acid, acetic acid, formic acid or mixture thereof. 10. The electrochemical oxidation process as claimed in claim 8, wherein the electrochemical setup comprises a graphite rod or Pt/C electrode as cathode material, and saturated calomel electrode (SCE) as reference electrode and a voltage applied is in range of 0.4 to 1.2 V.