Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
  • B01J21/06—Silicon, titanium, zirconium or hafnium; Oxides or hydroxides thereof
  • B01J21/08—Silica
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
  • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
  • B01J23/89—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with noble metals
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
  • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
  • B01J23/89—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with noble metals
  • B01J23/8906—Iron and noble metals
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J29/00—Catalysts comprising molecular sieves
  • B01J29/03—Catalysts comprising molecular sieves not having base-exchange properties
  • B01J29/0308—Mesoporous materials not having base exchange properties, e.g. Si-MCM-41
  • B01J29/0316—Mesoporous materials not having base exchange properties, e.g. Si-MCM-41 containing iron group metals, noble metals or copper
  • B01J29/0325—Noble metals
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J29/00—Catalysts comprising molecular sieves
  • B01J29/03—Catalysts comprising molecular sieves not having base-exchange properties
  • B01J29/0308—Mesoporous materials not having base exchange properties, e.g. Si-MCM-41
  • B01J29/0316—Mesoporous materials not having base exchange properties, e.g. Si-MCM-41 containing iron group metals, noble metals or copper
  • B01J29/0333—Iron group metals or copper
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J35/00—Catalysts, in general, characterised by their form or physical properties
  • B01J35/30—Catalysts, in general, characterised by their form or physical properties characterised by their physical properties
  • B01J35/391—Physical properties of the active metal ingredient
  • B01J35/393—Metal or metal oxide crystallite size
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J35/00—Catalysts, in general, characterised by their form or physical properties
  • B01J35/40—Catalysts, in general, characterised by their form or physical properties characterised by dimensions, e.g. grain size
  • B01J35/45—Nanoparticles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
  • B01J37/02—Impregnation, coating or precipitation
  • B01J37/03—Precipitation; Co-precipitation
  • B01J37/031—Precipitation
  • B01J37/035—Precipitation on carriers
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
  • C07C29/48—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by oxidation reactions with formation of hydroxy groups
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
  • C07C51/10—Preparation of carboxylic acids or their salts, halides or anhydrides by reaction with carbon monoxide
  • C07C51/145—Preparation of carboxylic acids or their salts, halides or anhydrides by reaction with carbon monoxide with simultaneous oxidation

Definitions

• the present invention relates to a catalyst for partial oxidation of substrate to value-added products under ambient conditions. More particularly, the present invention relates to a modified silica-supported bimetallic catalyst (MiMi-mod-SiOi) for partial oxidation of substrates (e.g., alkanes such as methane, ethane, propane etc.) to value-added products under ambient conditions where the value-added products are alcohols (methanol, ethanol, propanol, etc.), and acids (acetic acid, etc.). More particularly, the present invention relates to a catalyst for partial oxidation of substrates to value-added products under ambient conditions using hydrogen peroxide (H2O2) solution or in-situ formed H2O2 using H2 and O2 gases.
• H2O2 hydrogen peroxide
• Methane is the simplest organic molecule in nature, consisting of one carbon atom bonded with four hydrogen atoms. Methanol is only one atom change away, with one of the hydrogen atoms replaced by a hydroxyl (OH) group. Methanol, the initial product of methane oxidation, is a desirable product of conversion because it retains much of the original methane energy in a room temperature transportable, storable liquid that can be used directly as a fuel or converted to other valuable products. Studies in this area are rapidly increasing, with the desire to find a stable, active, and selective catalyst for CH4 conversion into methanol. Several catalysts have been proposed and studied to perform methanol synthesis from CH4 and H2O2.
• H2O2 by anthraquinone method suffers from several disadvantages, such as requiring toxic solvents, multiple steps and significant energy and risk during transportation.
• the direct synthesis of H2O2 from H2 and O2 gases using metal catalysts can be a solution to solve this problem.
• the key problem is stabilizing the resulting H2O2 because H2O2 simultaneously undergoes decomposition to water in presence of the same catalysts employed for its formation.
• the main objective of the present invention is to provide a modified silica-supported bimetallic catalyst (MiM2-mod-SiO2) for partial oxidation of substrate to value-added product(s) under ambient conditions.
• MiM2-mod-SiO2 modified silica-supported bimetallic catalyst
• Another objective of the present invention is to provide a process for the preparation of said modified silica-supported bimetallic catalyst (MiM2-mod-SiO2) for partial oxidation of substrate to value-added product(s) under ambient conditions.
• Another objective of the present invention is to provide a process for preparing in-situ H2O2 from H2 and O2 at ambient pressure conditions.
• Another objective of the present invention is to provide a process for preparing methanol or ethanol by reacting methane or ethane with H2O2 solution or in-situ H2O2 from H2 and O2 and said catalyst.
• Another objective of the present invention is to provide a process for preparing acids by reacting CO with methane and oxidant using the same process above and said catalyst.
• Another objective of the present invention is to provide a process for preparing acetic acid by reacting CO with methane produced herein above and said catalyst.
• Another objective of the present invention is to demonstrate the scope of the present invention for the production of higher alcohols from higher alkanes using said catalyst.
• Another objective of the present invention is to demonstrate the scope of the present invention for the production of higher acids by reacting higher alkanes with CO using the said catalyst using the same processes.
• the present invention provides a modified silica-supported bimetallic catalyst (MiM2-mod-SiO2) for partial oxidation of alkanes to values added products under ambient conditions.
• the present invention relates to a catalyst system, comprising: a) a modified silica- support (mod-SiO2), and b) a bimetallic catalysts (M1M2), wherein the modified silica-support comprises silicon dioxide or modified silicon dioxide in the form of hydrophobic S i O 2, wherein the bimetallic catalysts comprise transition metal (Mi) and noble metal (M2), and wherein the bimetallic catalysts are deposited onto said modified silica-support with amount is in the range of 0.1 to 10.0 wt. % of the total weight of the catalyst system.
• mod-SiO2 modified silica-support
• M1M2 bimetallic catalysts
• the modified silica-support comprises silicon dioxide or modified silicon dioxide in the form of hydrophobic S i O 2
• the bimetallic catalysts comprise transition metal (Mi) and noble metal (M2)
• the bimetallic catalysts are deposited onto said modified silica-support with amount is in the range of 0.1 to 10.0 w
• the catalyst system disclosed herein is a calcined catalyst system with amorphous in nature.
• the catalyst system has a surface area in the range of about 400 m 2 g 1 to about 600 m 2 g -1 .
• the modified silica-support (mod-SiC ) is in an amount in the range of 90 to 99 wt. % based on the total weight of the catalyst system.
• the modified silica-support (mod-SiC ) is in an amount in the range of 98 to 99.9 wt. % based on the total weight of the catalyst system.
• the transition metal (Mi) is selected from copper, nickel, iron and cobalt.
• the noble metal (M2) is selected from palladium, gold, platinum and silver.
• an average particle size of transition metal (Ml) and noble metal (M2), respectively, is in range of 1 to 10 nm.
• the present invention provides a modified silica-supported bimetallic catalyst (MiM2-mod-SiO2) for the synthesis of value-added products, wherein the supported catalyst comprises modified silicon oxide in the form of hydrophobic SiCh, one transition metal (Mi) selected from Cu, Ni, Fe, or Co and one noble metal (M2) selected from Pd, Au, Pt, or Ag, wherein both metals are deposited on a support in the range from 0.1 to 10.0 wt. % of the total weight of the supported catalyst.
• Mi transition metal
• M2 noble metal
• the present invention relates to a process of preparation of said catalyst system comprising steps of: a) preparing a modified silica- support (mod-SiO2) by reacting P123 as templating agent with TEOS and PMHS as silica precursors in the presence of 1.6 mol/L of HC1 solution at a temperature in the range of 35-40°C for a time period in the range of 22- 26 h to obtain a reaction mixture, followed by aging the reaction mixture at a temperature in the range of 90-1 KFC for a period of 42-48 h to afford the modified silica-support powder; b) calcining the modified silica-support powder at temperature in the range of 300-400 °C for time period in the range of 8-12 h at 1-5 degree/min ramp rate to obtain calcined modified silica-support; c) fabricating the transition metal (Ml) over the modified silica support of step a) or calcined modified silica support of step b) by dis
• the process disclosed herein is carried out in a continuous manner of steps a), b), c) and then finally d), or in an interchangeable manner of steps a), b), d) and then finally b).
• the transition metal precursor is selected from transition metal nitrate, transition metal sulphate and transition metal chloride.
• the noble metal precursor is selected from noble metal nitrate, noble metal sulphate and noble metal chloride.
• the modifier is ammonium chloride.
• the present invention relates to a process of preparation of value added products comprises: reacting a substrate with an oxidizing agent and carbon monoxide as optional additive, in presence of said catalyst system (M i Mi-mod-SiOj) as claimed in claim 1, maintained at one or more reaction conditions; wherein the oxidizing agent is H2O2 solution or in-situ generated H2O2, and wherein said in-situ generated H2O2 is produced in said reaction by using H2 and O2 gases.
• the catalyst system M i Mi-mod-SiOj
• the process of preparation of value added products is carried out in a gaseous phase in a continuous flow reactor or in a liquid phase in a batch reactor.
• the value-added products are selected from C1-C10 alcohols and Cl- C10 acids; and wherein the substrate is selected from Cl -CIO alkane or Cl -CIO alcohol.
• Fig. 3 represents the elemental mapping of the MiM2-mod-SiO2 supported catalyst.
• Fig. 6 represents the NMR data to confirm methanol and acetic acid formation (sample collected from a batch reactor where acetic acid is formed using methane, H2O2 and CO).
• Fig. 8 represents the catalytic activity of different Mi-mod. silica, M2-mod. silica and M1M2- mod. silica at the reaction temperature of 60°C and total pressure of 20 bar having the composition of 5 bar diluted O2 (25 % O2 + 75 % CO2 or N2)+ 5 bar diluted H2 (5 % H2 + 95 % CO2 or N2) + 10 bar CH 4 (99.99 % pure),
• Fig. 9 represents catalytic activity of MiM2-mod.silica catalyst at different pressures [Reaction temperature - 60°C, Total pressure - 10 bar (3 bar diluted O2 (25 % O2 + 75 % CO 2 or N 2 )+ + 3 bar diluted H 2 (5 % H 2 + 95 % CO 2 or N 2 ) + 4 bar CH 4 (99.99 % pure)), 20 bar ( 5 bar diluted O2 + 5 bar diluted H2+ 10 bar CH 4 ), and 30 bar (7 bar diluted O2 + 7 bar diluted H2 + 14 bar CH 4 ).
• Fig. 10 represents the catalytic activity of AuFeHS by varying the reaction pressure in the batch process, confirming the 10 bar as the optimized reaction pressure for effective methane conversion.
• Reaction conditions 25 mg of catalyst, time period of 30 min, 5-30 bar of methane, 0.5 mL of H2O2 (30% w/v), and 20 mL H2O, at 60G.
• Fig. 11 represents the catalytic activity analysis in the batch process of AuFeHS at various temperatures, confirming 60X2 as the optimized temperature.
• Reaction conditions 25 mg catalyst, time period of 30 min, 10 bar of methane, 0.5 mb of H2O2 (30 % w/v), and 20 mL H2O, temp, in the range of 30-80X2.
• Fig. 12 represents the catalytic activity analysis in the batch process of various catalysts, confirming AuFeHS as the best active catalyst among all tested catalysts. This analysis further confirms that hydrophobicity plays a key role in the effective conversion of methane to methanol. Reaction conditions: 25 mg catalyst, time period of 30 min, 10 bar methane, 0.5 mL H2O2 (30% w/v), and 20 mL H 2 O, at 60X2.
• Fig. 13 represents the catalytic activity analysis in the batch process of AuFeHS at various temperatures confirming 50 °C as optimized temperature of efficient acetic acid production. Reaction conditions: 50 mg catalyst, time period of 30 min, 20 bar methane, 5 bar CO, 0.5 mL H2O2 (30 % w/v), and 20 mL H2O, temp, in the range of 50-70X2.
• Fig. 14 represents the catalytic activity of various catalysts under the batch process for acetic acid production: Reaction conditions: 50 mg catalyst, time period of 30 min, 20 bar methane, 5 bar CO, 0.5 mL H2O2 (30 % w/v), and 20 mL H2O, at 50C.
• Fig. 16 represents the catalytic activity of AuFeHS in a continuous flow reactor, confirming the stability of the catalyst. Reaction conditions: 100 mg catalyst, temp, of 80X2, 2 mL/h H2O2 (15% w/v) flow, and methane flow 20 mL/min, for 1-7 h.
• Fig. 17 represent the catalytic activity of AuFeHS, at various pressure in the batch reactor: Reaction conditions: 50 mg catalyst (AuFeHS), time period of 30 min, temp, of 60X2, 20 mL H2O, and 10-30 bar (methane+d-H2+d-O2)
• substrate may be related to alkanes (C1-C10 or more, straight or branched chains) or alcohols (C1-C10 or more, straight or branched chains) and so on, depending upon the type of product sought to be produced.
• ambient conditions or “specific reaction conditions” provided herein may be defined by specific temperature, pressure, weight, hourly space velocity and molar ratio ranges, which are lower or much lower or better than the reported methods for obtaining said value-added products under similar conditions.
• catalyst system “modified silica-supported catalyst”, “modified silica-supported bimetallic catalyst”, “supported catalyst(s)” or “calcined supported catalyst(s)” provided and used herein throughout the specification possess or have the same meaning or nearly the same meaning covering the claimed metal catalyst(s) supported onto modified silica.
• the present invention provides a modified silica-supported bimetallic catalyst (M i N -mod- SiCh) for partial oxidation of substrate to value-added product(s) under ambient conditions.
• the present invention provides a modified silica-supported bimetallic catalyst (MiMi-mod-SiOz) for the synthesis of value-added products, wherein the supported catalyst comprises silicon dioxide or modified silicon dioxide in the form of hydrophobic SiOi. one transition metal (Mi) selected from Cu, Ni, Fe, or Co and one noble metal (M2) selected from Pd, Au, Pt, or Ag, wherein both the metals are deposited on a support in the range from 0.1 to 10.0 wt. % of the total weight of the supported catalyst.
• Mi transition metal
• M2 noble metal
• the metals M1M2 deposited overall onto the silica or modified silica surface may be done by deposition precipitation method.
• the modified silica-supported catalyst (MiMi-mod-SiOi) is a calcined supported catalyst and the organosilica content in the form of -(CH3) n - ranges from 10 to 60% by weight, preferably from 40 to 50 wt % based on the total weight of the modified supported catalyst.
• the modified silica-supported catalyst (M 1 Mi-inod-SiOz.) comprises at least one noble metal (M2) from 0.1 to 2.0 wt% based on the total weight of the calcined catalyst, more preferably from 0.2 to 1.0 wt %.
• the modified silica-supported catalyst comprises at least one transition metal (Mi) from 0.1 to 2.0 wt% based on the total weight of the calcined catalyst, more preferably from 0.2 to 1.0 wt %.
• the modified silica-supported catalyst (MiMi-mod-SiCh) is calcined and shows an amorphous structure as determined by XRD (as shown in Fig. 4).
• the average particle size of the transition metal (Mi) is less than 10 nm, preferably less than 4 nm, more preferably less than 1 nm as determined by HRTEM. (As shown in Fig. 2)
• the average particle size of noble metal (M2) is less than 10 nm, as determined by HRTEM, preferably less than 10 nm, more preferably less than 5 nm, and even more preferably less than 2 nm. (as shown in Fig. 2 and 3).
• the average particle size of transition metal (Mi) is in range of 1 to 10 nm or 1 to 2 nm or 1 to 4 nm.
• the average particle size of noble metal (M2) is in range of 1 to 10 nm or 1 to 2 nm or 1 to 5 nm.
• the modified silica-supported catalyst is a calcined supported catalyst and has preferably a surface area in the range of about 400 m 2 g 1 to about 600 m 2 g -1 as determined according to N2 sorption method.
• the support present in said catalyst system is hydrophobically modified silica by an organic group (methyl/methoxy).
• Another embodiment of the present invention provides a process for the preparation of the said modified silica-supported bimetallic catalyst, wherein said process comprises the steps: a) preparing modified SiC by reacting Pl 23 with an equal amount of TEOS and PMHS in the presence of 1.6 mol/L HC1 solution at a temperature in the range of 35-40°C for a period in the range of 22-24 h followed by aging the reaction mixture at a temperature in the range of 105-110 °C for a period of 42-48 h to afford modified SiCF; calcined the modified silica-support powder at temperature in the range of 300-400 °C for time period in the range of 8-12 h at 1-5 degree/min ramp rate to obtain calcined modified modified support.
• transition metal (Mi) over the modified silica support obtained at step a) by treating the solution of transition metal precursor with modified silica support dissolved in DI water by controlling the pH of the reaction mixture (9-10) with 0.1M NaOH solution to afford loading of transition metal on a modified silica support, after calcination of powder sample at 350 °C catalyst labeled as (Mi-mod- SiO 2 ).
• the process of preparation of the modified silica-supported bimetallic catalyst is carried out in a continuous manner [steps a) to b) to c)] or interchangeable fashion [steps a) to c) to b) or steps a) to b) to c)].
• Another embodiment of the present invention provides a process for the preparation of unmodified silica, wherein said process comprises using only TEOS as a silica precursor for the synthesis of unmodified SiO 2 .
• Yet another embodiment of the present invention provides a process carried out in the gaseous phase in the continuous flow reactor or liquid phase in the batch reactor, wherein said process comprises of reacting substrate with an oxidizing agent such as H 2 O 2 solution or in-situ generated H 2 O 2 in the presence of a modified silica- supported catalyst (MIM 2 - mod-SiO 2 ) at specific reaction conditions, wherein the in-situ H 2 O 2 is produced in said reaction by using H 2 and O 2 gases.
• an oxidizing agent such as H 2 O 2 solution or in-situ generated H 2 O 2
• MIM 2 - mod-SiO 2 modified silica- supported catalyst
• the present invention provides a process for the preparation of value-added products from the substrate in the presence of oxidizing agent such as H 2 O 2 solution or in-situ generated H 2 O 2 , optionally CO, and said modified silica-supported catalyst (MiM 2 -mod-SiO 2 ) at specific reaction conditions, wherein the in-situ H 2 O 2 is produced in said reaction by using H 2 and O 2 gases.
• oxidizing agent such as H 2 O 2 solution or in-situ generated H 2 O 2 , optionally CO
• said modified silica-supported catalyst MoM 2 -mod-SiO 2
• the specific reaction conditions comprise one or more of the: i) a pressure is of 1 atm, ii) a temperature is at least 40- 100°C, iii) a feed stream in contact with the modified silica-supported catalyst (M1M2- mod-SiCh), or silica- supported catalyst (MiNfe-SiCh), or modified silica (mod-SiOi) at a weight hourly space velocity of 12000 cm 3 STP g cai h 1 , iv) the molar ratio of H2O2 to substrate in the feed stream is in the range of 1:1 to 1: 10.
• Reaction conditions 100 mg catalyst, atmospheric pressure (1 atm), methane flow 20 mL/min, H2O2 flow 2 mL/min, 4 h reaction data.
• GENERAL INFORMATION Product analysis.
• the gaseous products analysis was performed on a Nucon GC-5760 gas chromatography system equipped with a methanizer unit and flame ionization detector using a carbosieve packed column.
• the liquid products were quantified by GC analysis on a Nucon 5760 gas chromatography system equipped with a flame ionization detector using a 30 m length DB-624 capillary column.
• Liquid products were also quantified by solvent- suppressed 1H NMR on a Bruker 400 MHz spectrometer. The measurement was calibrated using an external standard method with a series of methanol solutions with known concentrations. Typically, 0.9 ml liquor after the reaction was mixed with 0.1 ml D2O to prepare a solution for NMR measurement.
• Tetraethoxysilane (TEOS) was used as a silica precursor, and Polymethylhydro siloxane (PMHS) was used as a modifier organic silica precursor.
• PMHS Polymethylhydro siloxane
• Non-ionic triblock copolymer P123 was used as a templating agent to generate mesoporosity in silica. All these materials/chemicals are obtained from OMKAR TRADERS, Pune, MH, India.
• transition metal nanoparticles over the modified silica support was performed by deposition precipitation method. Typically, 0.5 g of inod-SiCF support was dispersed in deionized water. Solution of a transition metal precursor of different concentrations (0.01, 0.025, and 0.05 M) was added to the support solution. The pH of the mixture was subsequently controlled by the dropwise addition of a 0.1 M NaOH aqueous solution between 9-10. The solution was stirred for another 1 hr at the same pH. The precipitate was centrifuged, washed with deionized water, and dried at 80°C overnight. The dried powder was calcined in static air at 340-360°C for 3.5-4.5 h. The weight loading of transition metal on modified silica ranges from 0.1 to 2%.
• Example 4 Process for methanol synthesis in continuous flow reactor using H2O2 as oxidant
• Catalyst performance was measured in continuous flow cotton plugged quartz reactor.
• An aqueous feed containing hydrogen peroxide (Thermo-Fischer, typically 15 V/V%) was controlled by a syringe pump and methane flow was controlled by a mass flow controller (Alicat). Both were fed down through the catalyst bed which was composed of layers of pelleted catalyst.
• the quartz reactor had a total length of 50 cm and an internal diameter of 8 mm. Liquid and gaseous products were separated in a coiled gas condenser and collected periodically for analysis over a time period.
• Example 5 Process for methanol synthesis in a batch reactor using H2O2 solution as oxidant-
• Example 6 Process for methanol synthesis in continuous flow reactor using in-situ generated H2O2 as oxidant
• Methane (CH4) cylinder (99.99 %), O2 cylinder in which 25% O2 diluted with CO2 or N2 and H2 Cylinder in which 5% H2 diluted with CO2 or N2 was used.
• the reactor was pressurized using 5 bar pressure from the cylinder of diluted O2 in which 25% O2 and the remaining 75% balanced with CO2 or N2, 5 bar H2 gas from the cylinder, which contains 5% H2 and 95% CO2 or N2 and 10 bar of methane cylinder (99.99 % pure).
• the solution was heated to desired reaction temperature (60°C). Once the temperature reached the set value, the solution was vigorously stirred at 950 rpm.
• the reaction was carried out for 30 min at 60 °C, and ice-cold water was constantly circulated during the reaction.
• the gas sample was collected in a gas bag after cooling the products. Liquid samples were collected after centrifugation and analyzed by gas chromatography.
• Catalyst performance was measured in continuous flow cotton plugged quartz reactor. Providing a feed stream comprising methane (99.99 % pure), carbon monoxide (99.99 % pure) and diluted H2O2 as feed stream putting in contact with the catalyst at a reaction temperature in the range of 40-100 °C and under a pressure of 1 atm and recovering the methanol from the effluents by an ice-cold condensation process below 10°C.
• An aqueous feed containing hydrogen peroxide was controlled by a syringe pump, and methane and carbon monoxide flow was controlled by a mass flow controller (Alicat). Both were fed down through the catalyst bed which was composed of layers of pelleted catalyst. Liquid and gaseous products were separated in a coiled gas condenser and collected periodically for analysis.
• Water flow was controlled by a syringe pump and gas flow was controlled by a mass flow controller (Alicat). Both were fed down through the catalyst bed which was composed of layers of pelleted catalyst.
• the quartz reactor had a total length of 50 cm and an internal diameter of 8 mm. Liquid and gaseous products were separated in a coiled gas condenser and collected periodically for analysis.
• Active catalyst composition contains only less than 1% of metal content

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• 2023
  • 2023-10-04 EP EP23874449.4A patent/EP4598677A1/de active Pending
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