CN116555809A - HER electrocatalyst and preparation method thereof - Google Patents

HER electrocatalyst and preparation method thereof Download PDF

Info

Publication number
CN116555809A
CN116555809A CN202310839719.3A CN202310839719A CN116555809A CN 116555809 A CN116555809 A CN 116555809A CN 202310839719 A CN202310839719 A CN 202310839719A CN 116555809 A CN116555809 A CN 116555809A
Authority
CN
China
Prior art keywords
electrocatalyst
nitrogen
containing substance
catalyst
preparation
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
CN202310839719.3A
Other languages
Chinese (zh)
Inventor
李爽
郑懿娟
张奔
马田
颜睿
汪茂
尹波
赵长生
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sichuan University
Original Assignee
Sichuan University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sichuan University filed Critical Sichuan University
Priority to CN202310839719.3A priority Critical patent/CN116555809A/en
Publication of CN116555809A publication Critical patent/CN116555809A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
    • C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
    • C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
    • C25B11/073—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material
    • C25B11/075—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of a single catalytic element or catalytic compound
    • C25B11/081—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the electrocatalyst material consisting of a single catalytic element or catalytic compound the element being a noble metal
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B1/00—Electrolytic production of inorganic compounds or non-metals
    • C25B1/01—Products
    • C25B1/02—Hydrogen or oxygen
    • C25B1/04—Hydrogen or oxygen by electrolysis of water
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B11/00—Electrodes; Manufacture thereof not otherwise provided for
    • C25B11/04—Electrodes; Manufacture thereof not otherwise provided for characterised by the material
    • C25B11/051—Electrodes formed of electrocatalysts on a substrate or carrier
    • C25B11/055—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the substrate or carrier material
    • C25B11/057—Electrodes formed of electrocatalysts on a substrate or carrier characterised by the substrate or carrier material consisting of a single element or compound
    • C25B11/065—Carbon
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/36—Hydrogen production from non-carbon containing sources, e.g. by water electrolysis

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Catalysts (AREA)

Abstract

The invention relates to a HER electrocatalyst and a preparation method thereof, and belongs to the field of catalysts. The invention provides a preparation method of an HER electrocatalyst, which comprises the following steps: dispersing rhodium salt or iridium salt in an alcohol solvent to form a stable and transparent solution, adding a nitrogen-containing substance into the solution, and stirring to dissolve the nitrogen-containing substance; adding the carbon substrate, and stirring and uniformly mixing; then standing, aging and complexing the obtained reaction system to obtain gel-like solid; and then placing the obtained gel-like solid in an inert gas environment, heating for 2-5 h at 65-75 ℃, then heating to 500-800 ℃ and keeping the temperature for 2-3 h, finally cooling to room temperature and standing for 1-2 h to obtain the HER electrocatalyst. The invention develops a novel N-doped carbon carrier loaded Rh or Ir nanocluster prepared electrocatalyst, and the obtained electrocatalyst shows excellent HER catalytic activity under a wide pH value range.

Description

HER electrocatalyst and preparation method thereof
Technical Field
The invention relates to a HER electrocatalyst and a preparation method thereof, and belongs to the field of catalysts.
Background
The energy crisis and environmental pollution are increasingly severe, and the need for developing renewable energy is urgent. Hydrogen is considered one of the most promising alternatives to fossil fuels. The production of hydrogen by electrocatalytic water splitting is a promising technology, enabling the development of global scale, sustainable and environmentally friendly energy systems. Noble metal materials (such as Pt-, pd-, ir-and Ru-based materials) are still considered to be the most advanced catalysts in HER due to their optimal free energy of the H-intermediate. However, noble metal materials are scarce in sources and expensive, limiting their practical use. Therefore, developing an efficient, low cost HER catalyst suitable for use at prevailing pH conditions remains a challenge.
In order to reduce the use of noble metals and adjust the performance of the catalyst, supported metal catalysts have been widely developed to increase the dispersibility of metals, thereby maximizing the utilization of metal atoms. In electrocatalytic, the carrier can not only increase electron conductivity and expose more active sites, but also induce a synergistic effect and improve electrocatalytic activity. The synergistic effect between the metal and the support caused by chemical interface bonds and charge transfer can affect the adsorption/desorption behavior of the reactants and intermediates and ultimately the electrocatalytic properties. Specifically, the synergistic effect is closely related to the geometry and electronic structure of the metal, and can be changed at any time through coordination engineering of catalytic atoms, thereby affecting the whole reaction kinetics. Local coordination engineering of monoatomic catalysts (SACs) is considered one of the most effective strategies for optimizing catalytic performance. For example, the coordination structure of single copper atom sites has been reported to have a critical impact on the selectivity and activity of metal catalysts. While SACs generally suffer from low apparent electrochemical activity and poor stability, the high atomic efficiency and apparent activity of clustered catalysts highlight their great potential in building efficient, stable electrocatalysts.
Disclosure of Invention
The invention adopts a simple method to construct the catalyst (named Rh) containing Rh-N or Ir-N coordinated N-doped carbon loaded Rh or Ir nanocluster x -N-C or Ir x -N-C）。Rh x -N-C or Ir x The N-C catalyst shows excellent universal HER performance at pH, with ultra low overpotential and excellent stability. At 0.5M H 2 SO 4 Rh in 1.0M KOH and 1.0M PBS solution x N-C catalyst at 10 mA cm -2 The overpotential was as low as 8, 16 and 109 mV, respectively. Rh (rhodium) x The optimal Rh-N coordination in N-C plays a crucial role in improving electron transfer, thus promoting H 2 Is generated.
The technical scheme of the invention is as follows:
the first technical problem to be solved by the invention is to provide a preparation method of HER electrocatalyst, which comprises the following steps:
dispersing rhodium salt or iridium salt in an alcohol solvent to form a stable and transparent solution, adding a nitrogen-containing substance into the solution, and stirring to dissolve the nitrogen-containing substance;
adding the carbon substrate, and stirring and uniformly mixing;
then standing, aging and complexing the obtained reaction system to obtain gel-like solid;
and then placing the obtained gel-like solid in an inert gas environment, heating for 2-5 h at 65-75 ℃, then heating to 500-800 ℃ and keeping the temperature for 2-3 h, finally cooling to room temperature and standing for 1-2 h to obtain the HER electrocatalyst.
Further, the nitrogen-containing substance is urea or melamine.
Further, the carbon substrate is ketjen black, carbon nanotubes or graphene.
Further, the rhodium salt is selected from: rhCl 3 ·xH 2 O、Rh(NO 3 ) 3 ·xH 2 O、Rh 2 (SO 4 ) 3 Or (NH) 4 ) 3 RhCl 6 。
Further, the iridium salt is selected from: irCl 3 ·xH 2 O。
Further, the mass ratio of the rhodium salt to the nitrogen-containing substance is 0.1-10: 200.
further, the mass ratio of the nitrogen-containing substance to the carbon substrate is 10-20: 1.
the second technical problem to be solved by the present invention is to provide a HER electrocatalyst, which is prepared by the above method.
Further, the electrocatalyst is a catalyst in which Rh clusters or Ir clusters are uniformly supported on a nitrogen-doped carbon support, and Rh-N coordination or Ir-N coordination is contained in the catalyst.
The invention has the beneficial effects that:
the invention prepares the electrocatalyst (named Rh) which is prepared by embedding Rh or Ir nanoclusters with rich Rh-N coordination or Ir-N coordination into N-doped carbon carriers x -N-C catalysts or Ir x -N-C catalyst) providing very high reactivity to HER over a broad pH range, rh obtained x -N-C catalyst at 0.5M H 2 SO 4 8mV, 16mV and 109 mV are required to reach 10 mA cm in 1.0M KOH and 1.0M PBS solutions, respectively -2 This is more advantageous than commercial Rh/C. Ir obtained x N-C catalyst in 1M KOH solution at 10 mA cm -2 The time overpotential was 76 mV. This work demonstrates the successful coordination of carbon supported Rh nanoclusters or Ir nanoclusters and provides a new strategy to design nanocluster-based electrocatalysts by coordination chemistry engineering to achieve excellent HER performance.
Drawings
Fig. 1: catalyst Rh obtained in example 1 x Dark field TEM image of N-C (fig. 1 a) and Rh cluster size profile (fig. 1 b).
Fig. 2: rh (rhodium) x HAADF-STEM results for N-C.
Fig. 3: rh (rhodium) x EDS element map of-N-C, FIG. 3a is Rh x -HRTEM dark field diagram of N-C, fig. 3b is Rh element profile, diagram3C is a C element profile and fig. 3d is an N element profile.
Fig. 4: a. rh (rhodium) x -XRD spectrum of N-C; b. rh (rhodium) x -an elemental content profile of N-C; c. XPS spectrum peak diagram of Rh 3d orbit; d. XPS spectrum peak pattern of N1 s orbits.
Fig. 5: a. LSV profile of catalyst in 1.0M KOH; b. the catalyst had a current density of 10 mA cm -2 An overpotential result graph at the time; c. tafel slope plot of catalyst in 1.0M KOH; d. TOF value and mass activity results for the catalyst.
Fig. 6: a. EIS test result diagram of catalyst; b. catalyst C dl Results graph.
Fig. 7: catalyst Rh obtained in example 1 x -stability test pattern of N-C.
Fig. 8: LSV plots for different catalysts; b, d. according to 0.5M H 2 SO 4 Tafel slope plot calculated from LSV curve in 1.0M PBS solution.
Fig. 9: a and b are respectively 0.5M H 2 SO 4 Stability test plots in 1.0M PBS solution.
Fig. 10: rh (rhodium) x LSV plot of N-C in different electrolytes.
Fig. 11: LSV plots of the catalysts obtained in examples 2-4 in 1.0M KOH.
Fig. 12: LSV graphs of the catalysts obtained in examples 5-7 in 1.0M KOH.
Fig. 13: LSV profile of the catalyst obtained in example 8 in 1.0M KOH.
Detailed Description
The invention adopts a simple method to construct the catalyst containing Rh-N coordination or Ir-N coordination N-doped carbon carrier loaded Rh or Ir nanocluster. Rh (rhodium) x -N-C catalysts or Ir x The N-C catalyst shows excellent pH universal HER performance with ultra low overpotential and strong stability. At 0.5M H 2 SO 4 Rh in 1.0M KOH and 1.0M PBS solution x N-C catalyst at 10 mA cm -2 The overpotential was as low as 8, 16 and 109 mV, respectively. The coordination chemistry of Rh-N molecules affects Rh andthe charge redistribution between the supports accurately regulates the geometry and electronic structure of the Rh species, optimizes the adsorption energy of the reaction intermediates, and finally improves the electrocatalytic performance. Rh (rhodium) x The optimal Rh-N coordination in N-C plays a crucial role in improving electron transfer, thus promoting H 2 Is generated. The work not only makes breakthrough progress in the aspect of coordination chemical engineering of the nanocluster-based electrocatalyst and realizes excellent HER performance, but also provides an in-depth research view for structure-activity relationship.
The following describes the invention in further detail with reference to examples, which are not intended to limit the invention thereto.
Example 1
3 mg RhCl 3 · xH 2 The O powder was dispersed in ethanol (2 mL) to form a stable and transparent solution. 200 mg urea was added to the above solution, and the mixture was stirred to dissolve the urea. Adding 20 mg Ke black, stirring for 30 min, transferring into a crucible, aging and complexing for 12 hr to obtain gel solid; the above operations were completed in a glove box. The gel-like solid was then placed in a tube furnace under argon (flow rate 100 mL min) -1 ) Heating to 70 ℃ at a heating rate of 1 ℃/min and keeping the temperature constant for 2 hours, then continuously heating to 600 ℃ at a heating rate of 5 ℃/min and keeping the temperature constant for 3 hours, cooling to room temperature and passivating in the same argon gas flow for 2 hours; grinding to obtain catalyst called Rh x -N-C。
Examples 2 to 4
The preparation was the same as in example 1, except that RhCl 3 · xH 2 The mass ratio of O to urea is 0.5:200 (example 2), 1:200 (example 3), 7.6:200 (example 4).
Examples 5 to 7
The preparation process is identical to example 1, except that it is warmed to 500℃and kept at constant temperature for 3 hours (example 5), to 700℃and kept at constant temperature for 3 hours (example 6), and to 800℃and kept at constant temperature for 3 hours (example 7).
Example 8
3 mg IrCl 3 ·xH 2 The O powder was dispersed in ethanol (2 mL) to form a stable and transparent solution. 200 mg urea was added to the above solution, and the mixture was stirred to dissolve the urea. Adding 20 mg Ke black, stirring for 30 min, transferring into a crucible, aging and complexing for 12 hr to obtain gel solid; the above operations were completed in a glove box. The gel was placed in a tube furnace under argon atmosphere (flow rate 100 mL min) -1 ) Heating to 70 ℃ at a heating rate of 1 ℃/min and keeping the temperature constant for 5 hours, then continuously heating to 800 ℃ at a heating rate of 5 ℃/min and keeping the temperature constant for 2 hours, cooling to room temperature and passivating in the same argon gas flow for 2 hours; grinding to obtain Ir x -an N-C catalyst.
Comparative example 1
Rh x Preparation of-C: 3 mg RhCl 3 ·xH 2 The O powder was dispersed in ethanol (2 mL) to form a stable and transparent solution. Adding 20 mg Ke black into the solution, stirring for 30 minutes, transferring into a crucible, aging and complexing for 12 hours to obtain gel solid. The above operations were completed in a glove box. The gel was placed in a tube furnace under argon atmosphere (flow rate 100 mL min) -1 ) Heating to 70 ℃ at a heating rate of 1 ℃/min and keeping the temperature constant for 2 hours, then continuously heating to 600 ℃ at a heating rate of 5 ℃/min and keeping the temperature constant for 3 hours, cooling to room temperature and passivating in the same argon gas flow for 2 hours; grinding to obtain Rh x -a C catalyst.
Comparative example 2
A commercial Pt/C was used as comparative example 2, which was assigned the designation 7440-06-4.
Comparative example 3
As comparative example 3, commercial Rh/C was used under the trade name 7440-16-6.
Comparative example 4
Rh x Preparation of N-C: 200 mg urea is dispersed in 2 mL ethanol, 20 mg Ke black is added to the above solution, stirred to disperse uniformly, and then transferred to a crucible for aging and complexing for 12 hours. Placing the above mixtureIn a tube furnace under argon atmosphere (flow rate 100 mL min) -1 ) Heating to 70 ℃ at a heating rate of 1 ℃/min and keeping the temperature constant for 3 hours, and then continuously heating to 800 ℃ at a heating rate of 5 ℃/min and keeping the temperature constant for 2 hours to obtain the N-C substrate. Dispersing above N-C in 5 mL ethanol, adding 3 mg RhCl 3 ·xH 2 O, after stirring for 20 minutes, 1 mL NaBH was added dropwise 4 Aqueous solution (containing NaBH) 4 6 mg), stirring for 30 min, washing by centrifugation, and vacuum drying at 70deg.C to obtain the product, designated Rh x /N-C。
Test example 1 catalyst Rh x Characterization of the morphology and structural analysis of N-C
Rh obtained in example 1 x TEM of N-C (FIG. 1 a) and Rh cluster size diagram (FIG. 1 b) as shown in FIG. 1, it can be seen from FIG. 1 that the resulting catalyst of the present invention exhibits a unique three-dimensional, porous and spherical structure; rh (rhodium) x The unique morphology of N-C was further studied by Transmission Electron Microscopy (TEM). TEM images show that Rh nanoclusters are uniformly dispersed in a carbon matrix with an average diameter of about 1.60 nm.
In addition, the Rh obtained in example 1 was uncovered using a high-angle annular dark-field scanning transmission electron microscope (HAADF-STEM) x -atomic resolution structure of the N-C catalyst. The high resolution STEM image clearly shows the lattice of Rh (111) planes, demonstrating nanocluster formation (fig. 2). Elemental mapping of energy dispersive X-ray spectroscopy (EDX) (fig. 3 a-d) confirmed the apparent aggregation of Rh and the uniform spatial distribution of Rh nanoclusters in the N-doped carbon substrate.
FIG. 4a shows Rh obtained from example 1 x -X-ray diffraction (XRD) pattern of N-C with Rh x C (comparative example 1) as reference. There are two weak and broad diffraction peaks at 25 ° (002) and 44 ° (101), which can be attributed to disordered and defective carbon. Furthermore, no peak of the metallic phase was observed, which is consistent with the TEM results. To further analyze Rh x -composition and electronic structure of N-C, we use X-ray photoelectron spectroscopy (XPS). Rh (rhodium) x The XPS data of N-C further confirm that the catalyst consists of Rh, C, N and O elements. Table using XPSAnalysis of the surface composition shows Rh x Atomic ratio of-C and Rh x N-C are similar (FIG. 4 b). FIG. 4c depicts Rh x -Rh 3d spectrum of N-C, which can be divided into two distinct peaks of metal (307.57, 312.17 eV) and oxidized Rh (309.47, 314.17 eV) species. Notably, rh x Rhodium metal in C (Rh) 0 ) Is higher than Rh x N-C, which means that the introduction of N results in a large number of electrons being transferred from Rh to N, thereby reducing the electron density around the Rh atom. Rh (rhodium) x The high resolution N1 s spectrum of N-C (fig. 4 d) confirms the formation of Rh-N bonds, which can be seen from the peak of binding energy 397.38 eV corresponding to the metal-N bonds. Furthermore, the peaks at 398.4, 399.82 and 401.08 are assigned to pyridyl N, pyrrolyl N and graphitic N, respectively, indicating doping of heteroatom N in carbon.
Test example 2 Rh x Electrocatalytic performance test of N-C
Due to Rh x The unique structure of N-C, consisting of Rh nanoclusters and N-doped carbon, we evaluated its HER electrocatalytic performance in an argon saturated 1.0M KOH solution.
Preparation of Ink: catalyst powder (10 mg) was mixed with 100 μl Nafion solution (5 wt%) and 900 μl ethanol, and catalyst ink was prepared in an ultrasonic bath; then 5. Mu.L of the catalyst ink was transferred to the GC surface to give a catalyst loading of 0.25 mg cm -2 。
Electrocatalytic testing: electrochemical performance was performed using a standard three electrode system by Gamry reference 600 workstation (Gamry, USA). 33 g KOH (reagent grade, 85%, aladin Co.) was dissolved in 500 mL ultra pure water to prepare an electrolyte. A Reversible Hydrogen Electrode (RHE) was used as a reference electrode and placed in a 1.0M saturated KOH solution with a graphite rod as the counter electrode. In an area of 0.196 to 0.196 cm 2 The glassy carbon Rotary Disk Electrode (RDE) was used as a substrate for a working electrode, and the hydrogen evolution reaction activities of various catalysts were evaluated. The polarization curves measured were at 1.0M KOH, 1.0M PBS or 0.5M H for saturated Ar 2 SO 4 In an electrolyte, the scanning rate is 10 mV s -1 The rotating speed is 1600 rpm, and the automatic correction is compensated in real time. At a current density of 10 mA cm -2 Under the condition of adopting a chronopotentiometryFor Rh x The stability test was carried out on the N-C catalysts and on the products obtained in the comparative examples.
The calculation formula of the mass activity is as follows: mass activity = I/m, where I (a) is the measured current and m (mg) is the mass of Rh supported on the glassy carbon electrode.
The conversion frequency (TOF) is calculated as: tof=i/2 nF, where I (a) is the measured current. F is Faraday constant (96485 mol) -1 ). n=m/M, n is the number of active bits (mol) of Rh supported on the glassy carbon electrode, M is the mass of Rh, and M is the atomic mass.
For comparison, we also evaluated Rh under the same conditions x -HER performance of C, 20wt% Pt/C and 10wt% Rh/C. As shown in the linear sweep voltammogram of FIG. 5a, rh obtained in example 1 compared to Rh/C and Pt/C x N-C (Rh: 2.85 wt%) showed significantly high HER activity. At 10 mA cm -2 Is matched with Rh under the current density of (1) x Comparison of-C (98 mV), rh/C (79 mV) and Pt/C (38 mV) (FIG. 5 b), rh obtained in example 1 x N-C requires a much lower overpotential of 16 mV. Rh (rhodium) x The Tafel slope of N-C is only 43 mV dec -1 Far below Pt/C (53 mV dec -1 ）、Rh/C（149 mV dec -1 ) And Rh x -C（100 mV dec -1 ) The excellent HER performance of the resulting catalyst of the invention was also further demonstrated (fig. 5 c).
Rh was considered in view of the cost of the catalyst in practical use x -N-C、Rh x The mass activity of the-C and commercial Rh/C catalysts was assessed by normalizing the LSV curve with the mass of Rh, respectively. As shown in fig. 5d, rh x N-C shows excellent mass activity in 1.0M KOH solution. At an overpotential of 100mV, rh x N-C exhibits 12.685A mg -1 High mass activity of Rh, which is higher than Rh x -C（1.615 A mg -1 ) About 7.8 times higher than Rh/C (0.56A mg -1 ) 22.6 times higher. Another key factor in assessing the intrinsic catalytic performance of electrocatalysts is turnover frequency (TOF). Rh at an overpotential of 100mV x N-C exhibits 6.77. 6.77H 2 s -1 Is significantly higher in turnover frequency than Rh x -C（0.86 H 2 s -1 ）、Rh/C（0.30 H 2 s -1 ) Even most of the reported HER electrocatalysts are high. This result further confirms Rh obtained in the present invention x Active site ratio Rh of the N-C catalyst x C is much higher, i.e. Rh x -a great advantage of N-C in terms of HER electrocatalytic performance.
Electrochemical impedance testing (EIS) was used to study electron/proton transfer at the catalyst and electrolyte interface, which may also account for Rh x N-C has the fastest electron transfer during HER (fig. 6 a). Furthermore, we studied the double layer capacitance of the catalyst (C dl ) It is positively correlated with the electrochemically active surface area (ECSA). As shown in fig. 6b, rh x C of-N-C dl Higher, indicating that its electrocatalytic ECSA is larger. This can be attributed to the layered ordered porous structure, which highly exposes the Rh nanoclusters, improving the utilization of the Rh active sites.
To further evaluate Rh x Practical value of N-C electrocatalyst, we performed a time-voltage test to evaluate its stability in application, the results showing that Rh obtained in example 1 x N-C catalyst at 10 mA cm -2 Has stable HER catalytic activity at current densities (fig. 7).
To study Rh x -HER catalytic activity of N-C at different pH, we further studied it at 0.5M H 2 SO 4 Performance in solution and 1.0M Phosphate Buffered Saline (PBS). As shown in fig. 8a, c, rh x -N-C at 0.5M H 2 SO 4 Solution and 1.0M PBS at 10 mA cm -2 Respectively exhibit overpotential of 8 and 109 mV. Rh under alkaline and neutral conditions x N-C shows a significantly higher current density at different overpotential than Pt/C. In addition, in the acidic solution, rh x The current densities of N-C and Pt/C are not significantly different. Rh under acidic, neutral and alkaline conditions x The Tafel slope of N-C is lower than Rh/C and Pt/C (FIGS. 8b, d). These results indicate that Rh x -N-C is a highly efficient HER electrocatalyst. In addition, the pH value is compared with Pt/C x HER performance shadow of-N-CLess loud, indicating Rh x N-C can effectively overcome the hydrolysis energy barrier, which is critical for catalyzing HER under non-acidic conditions. In addition, rh x N-C shows excellent stability in both acidic and neutral solutions (FIGS. 9a, b).
The Rh-cluster-supported N-C material (Rh) obtained in comparative example 4 of the invention x N-C) LSV curves in different electrolytes are shown in FIG. 10, rh is known from FIG. 10 x N-C at 1.0M KOH, 0.5M H 2 SO 4 10 mA cm was reached in 1.0M PBS -2 The required overpotential for the current density of (a) is 26, 86, 273 mV respectively, which are inferior to Rh x -N-C, confirming Rh obtained by the process of the invention x -N-C has a Rh-N coordination structure with a significant enhancement of HER catalysis.
In addition, the present invention also investigated the HER catalytic activity of the catalysts obtained in examples 2 to 8. As can be seen from FIG. 11, the catalysts obtained in examples 2 to 4 all have excellent HER catalytic activity, examples 2, 3 and 4 have a catalyst activity of 10 mA cm -2 The overpotential at this time was 111 mV, 66 mV and 14 mV, respectively.
As can be seen from FIG. 12, the electrocatalyst with better HER catalytic activity can be obtained in the heat preservation range of 500-800 ℃ in examples 5-7 at 10 mA cm -2 The overpotential at this time was 91 mV, 78 mV and 61 mV, respectively.
Ir obtained in example 8 x The N-C catalyst was in 1.0M KOH electrolyte to give 10 mA cm -2 The overpotential required at current density of (c) is 75 mV (see fig. 13); it can be seen that Ir obtained by the present invention x The N-C catalyst also has better HER catalytic performance.
In conclusion, the invention develops a novel electrocatalyst prepared from Rh or Ir nanoclusters loaded by an N-doped carbon carrier, and the obtained electrocatalyst shows excellent HER catalytic activity in a wide pH value range, and needs over-potentials as low as 8, 16 and 108 mV to reach 10 mA cm in acidic, alkaline and neutral electrolytes respectively -2 Is used for the current density of the battery. The unique coordination chemical structure of Rh-N or Ir-N accurately adjusts the geometry and electronic structure of Rh or Ir species. This rational coordination chemistry strategy can induce electronsTransfer from Rh sites to N sites, thereby causing redistribution of electrons on the carbon support, optimizing the adsorption energy of the reaction intermediate, and eventually improving the electrocatalytic performance. Thus, rh x -N-C or Ir x The discovery of N-C catalysts provides a unique idea for rational design of efficient active sites, i.e. modulating adsorption of intermediates by modulating coordination chemistry.

Claims (9)

1. A method of preparing a HER electrocatalyst, comprising:
dispersing rhodium salt or iridium salt in an alcohol solvent to form a stable and transparent solution, adding a nitrogen-containing substance into the solution, and stirring to dissolve the nitrogen-containing substance;
adding the carbon substrate, and stirring and uniformly mixing;
then standing, aging and complexing the obtained reaction system to obtain gel-like solid;
and then placing the obtained gel-like solid in an inert gas environment, heating for 2-5 h at 65-75 ℃, then heating to 500-800 ℃ and keeping the temperature for 2-3 h, finally cooling to room temperature and standing for 1-2 h to obtain the HER electrocatalyst.
2. The method for preparing a HER electrocatalyst according to claim 1, wherein the nitrogen-containing substance is urea or melamine.
3. The method for preparing a HER electrocatalyst according to claim 1 or 2, wherein the carbon substrate is ketjen black, carbon nanotubes or graphene.
4. A method of preparing a HER electrocatalyst according to claim 1 or 2, wherein the rhodium salt is selected from: rhCl 3 ·xH 2 O、Rh(NO 3 ) 3 ·xH 2 O、Rh 2 (SO 4 ) 3 Or (NH) 4 ) 3 RhCl 6 。
5. According to claim 1 or 2A process for the preparation of HER electrocatalyst, characterized in that the iridium salt is selected from IrCl 3 · xH 2 O。
6. The preparation method of the HER electrocatalyst according to claim 1 or 2, wherein the mass ratio of rhodium salt or iridium salt to nitrogen-containing substance is 0.1-10: 200.
7. the preparation method of the HER electrocatalyst according to claim 1 or 2, wherein the mass ratio of the nitrogen-containing substance to the carbon substrate is 10 to 20:1.
8. a HER electrocatalyst, characterized in that it is produced by the production process according to any one of claims 1 to 7.
9. A HER electrocatalyst according to claim 8, wherein the electrocatalyst is a support in which Rh clusters or Ir clusters are uniformly supported on nitrogen-doped carbon, and wherein the electrocatalyst comprises Rh-N coordination or Ir-N coordination.
CN202310839719.3A 2023-07-10 2023-07-10 HER electrocatalyst and preparation method thereof Withdrawn CN116555809A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202310839719.3A CN116555809A (en) 2023-07-10 2023-07-10 HER electrocatalyst and preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202310839719.3A CN116555809A (en) 2023-07-10 2023-07-10 HER electrocatalyst and preparation method thereof

Publications (1)

Publication Number Publication Date
CN116555809A true CN116555809A (en) 2023-08-08

Family

ID=87486563

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202310839719.3A Withdrawn CN116555809A (en) 2023-07-10 2023-07-10 HER electrocatalyst and preparation method thereof

Country Status (1)

Country Link
CN (1) CN116555809A (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108232210A (en) * 2018-01-18 2018-06-29 兰州交通大学 A kind of high stability, low-load amount ultra-dispersed noble metal electrocatalyst preparation method
WO2018195045A1 (en) * 2017-04-17 2018-10-25 President And Fellows Of Harvard College Metal-doped catalyst, methods for its production and uses thereof
US20210355588A1 (en) * 2018-10-02 2021-11-18 The Regents Of The University Of California Ruthenium and nitrogen doped carbon matrix catalyst and methods for making and using thereof
CN113745544A (en) * 2021-08-18 2021-12-03 江西理工大学 Electrocatalyst, preparation method and application
CN116219477A (en) * 2023-05-09 2023-06-06 四川大学 Nano hybrid material and preparation method and application thereof

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018195045A1 (en) * 2017-04-17 2018-10-25 President And Fellows Of Harvard College Metal-doped catalyst, methods for its production and uses thereof
CN108232210A (en) * 2018-01-18 2018-06-29 兰州交通大学 A kind of high stability, low-load amount ultra-dispersed noble metal electrocatalyst preparation method
US20210355588A1 (en) * 2018-10-02 2021-11-18 The Regents Of The University Of California Ruthenium and nitrogen doped carbon matrix catalyst and methods for making and using thereof
CN113745544A (en) * 2021-08-18 2021-12-03 江西理工大学 Electrocatalyst, preparation method and application
CN116219477A (en) * 2023-05-09 2023-06-06 四川大学 Nano hybrid material and preparation method and application thereof

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
KOTTARATHIL SHIJINA等: "Melamine formaldehyde–metal organic gel interpenetrating polymer network derived intrinsic Fe–N-doped porous graphitic carbon electrocatalysts for oxygen reduction reaction", 《NEW J. CHEM.》, vol. 42, pages 18690 - 18701 *
LUHONG FU等: "Discrepant roles of adsorbed OH* species on IrWOxfor boosting alkaline hydrogen electrocatalysis", 《SCIENCE BULLETIN》, vol. 65, pages 1735 - 1742 *
马贵香;赵江红;郑剑锋;朱珍平;: "氮掺杂石墨烯的制备及其电催化氧气还原性能", 新型炭材料, no. 04, pages 258 - 265 *

Similar Documents

Publication Publication Date Title
Yu et al. Superb all‐pH hydrogen evolution performances powered by ultralow Pt‐decorated hierarchical Ni‐Mo porous microcolumns
Zhang et al. A defect-driven atomically dispersed Fe–N–C electrocatalyst for bifunctional oxygen electrocatalytic activity in Zn–air batteries
Qin et al. Ultrathin IrRu nanowire networks with high performance and durability for the hydrogen oxidation reaction in alkaline anion exchange membrane fuel cells
CN110993968B (en) Preparation method and electrocatalysis application of carbon aerogel single metal atom catalyst
CN107749483B (en) Catalyst for hydrogen-air fuel battery cathode material and preparation method thereof
CN116666669B (en) VN-supported Ir cluster, preparation method thereof and application thereof in catalyst
Bai et al. CoNi-based metal–organic framework nanoarrays supported on carbon cloth as bifunctional electrocatalysts for efficient water-splitting
Liu et al. Identification of the optimal doping position of hetero-atoms in chalcogen-doped Fe–N–C catalysts for oxygen reduction reaction
Xu et al. Antimony oxides-protected ultrathin Ir-Sb nanowires as bifunctional hydrogen electrocatalysts
CN116219477B (en) Nano hybrid material and preparation method and application thereof
Liang et al. Yolk-shell FeCu/NC electrocatalyst boosting high-performance zinc-air battery
CN111151281A (en) C3N4Modified Co3O4Self-supported ultrathin porous nanosheet and preparation method and application thereof
CN114808026B (en) Two-dimensional metal organic framework nano-sheet supported noble metal monoatomic catalyst and preparation method and application thereof
CN115360369A (en) Preparation method and application of monatomic Fe-N-C catalyst
CN112510217B (en) Carbon-supported platinum yttrium catalyst and preparation method and application thereof
CN112331866B (en) Fe/Co-N-MCF composite catalyst for fuel cell and preparation method thereof
CN116555809A (en) HER electrocatalyst and preparation method thereof
Yuan et al. A highly active and durable PtCoFe/nitrogen-incorporated carbon skeleton catalyst evolved from HA-CoFe-ZIF template for methanol electrooxidation
Zhao et al. Ultrasmall Mo2C Embedded in N‐Doped Holey Carbon for High‐Efficiency Electrochemical Oxygen Reduction Reaction
CN113299929A (en) Preparation method of F, S, N co-doped Fe-N-C fuel cell oxygen reduction catalyst
Hu et al. Iron‐incorporated Ni4Mo Hierarchical Nanorod Arrays for Promoted Electrocatalytic Oxygen Evolution Reaction
Negondeni et al. Synthesizing Pt-Ni/C Nanoframes electrocatalyst using the solvothermal and in-house developed method for PEM fuel cells
CN112366326B (en) Preparation method and application of carbon-coated nickel aerogel material
Zhou et al. Embedding isolated iron into biomass-derived porous carbon as efficient electrocatalysts for O2 and CO2 reduction
CN117438573A (en) Preparation of tungsten nitride nanowire loaded ruthenium and application of tungsten nitride nanowire loaded ruthenium in hydrogen oxidation reaction

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
WW01 Invention patent application withdrawn after publication

Application publication date: 20230808

WW01 Invention patent application withdrawn after publication