Non-noble metal hydrogen evolution electrocatalyst based on structural nanocrystallization combination synergistic modification and preparation method and application thereof
1. The non-noble metal hydrogen evolution electrocatalyst based on structural nanocrystallization combined synergistic modification is characterized in that: the catalyst consists of a metal boride active phase, an oxide matrix phase and a carrier, wherein the metal boride active phase is distributed on the surface of the oxide matrix phase in a nanoparticle form, and the oxide matrix phase is loaded on the carrier.
2. The non-noble metal hydrogen evolution electrocatalyst based on structural nanocrystallization in combination with synergistic modification according to claim 1, characterized in that: the metal boride active phase is a transition metal boride, and the oxide matrix phase is a transition metal oxide; the carrier is selected from foamed metal, metal mesh, ion exchange resin, molecular sieve or porous carbon material; the transition metal refers to one or a combination of several of Co, Ni, W, Mo, etc.
3. The non-noble metal hydrogen evolution electrocatalyst based on structural nanocrystallization in combination with synergistic modification according to claim 1, characterized in that: the metal boride active phase exists in an amorphous form, and the particle size is 3-15 nm.
4. The non-noble metal hydrogen evolution electrocatalyst based on structural nanocrystallization in combination with synergistic modification according to claim 1, characterized in that: the oxide matrix phase exists in an amorphous or nanocrystalline form; the oxide matrix phase contains oxygen vacancies and has a nano-porous structure, and the size of the nano-pores is 2-10 nm.
5. The preparation method of the non-noble metal hydrogen evolution electrocatalyst based on structural nanocrystallization combined synergistic modification, which is characterized by comprising the following preparation steps:
(1) adding a carrier material into an aqueous solution containing a transition metal salt and a precipitator, and growing a metal oxide precursor with a nano structure on the surface of the carrier material through a hydrothermal reaction;
(2) cleaning and drying the metal oxide precursor obtained in the step (1), and then carrying out high-temperature heat treatment in an inert atmosphere;
(3) and (3) carrying out boronization treatment on the metal oxide precursor subjected to heat treatment obtained in the step (2) to obtain the non-noble metal hydrogen evolution electrocatalyst based on structural nanocrystallization combined synergistic modification.
6. The method for preparing the non-noble metal hydrogen evolution electrocatalyst based on structural nanocrystallization combined synergistic modification according to claim 5, wherein: the transition metal salt in the step (1) is at least one of halide, nitrate, sulfate, sulfamate, acetate or oxygen-containing or oxygen-free acid salt of the transition metal; the transition group metal refers to one or a combination of more of Co, Ni, W or Mo; the precipitator is at least one selected from sodium molybdate, sodium tungstate, ammonia water, urea and ammonium molybdate; the concentration of the transition metal salt in the step (1) is 0.0001-0.2M, and the concentration of the precipitant is 0.0001-0.3M; the hydrothermal reaction temperature is 90-180 ℃; the time is 3-10 h; the inert atmosphere in the step (2) is argon; the temperature of the high-temperature heat treatment is 250-550 ℃; the time of the high-temperature heat treatment is 1-5 h.
7. The method for preparing the non-noble metal hydrogen evolution electrocatalyst based on structural nanocrystallization combined synergistic modification according to claim 5, wherein: the boronizing step in step (3) is to immerse the heat-treated metal oxide precursor into a solution containing NaBH4And carrying out boronization treatment on the mixed solution of NaOH.
8. The method for preparing the non-noble metal hydrogen evolution electrocatalyst based on structural nanocrystallization combined synergistic modification according to claim 7, wherein: the solvent of the mixed solution is a mixed solvent of ethylene glycol and deionized water; the proportion of ethylene glycol to deionized water in the mixed solvent is 0/1-4/1; the concentration of NaOH in the mixed solution is 0.05M-0.5M; NaBH in the mixed solution4The concentration of (A) is 0.5M to 5M.
9. The method for preparing the non-noble metal hydrogen evolution electrocatalyst based on structural nanocrystallization combined synergistic modification according to claim 7, wherein: the boronizing temperature is 25-95 ℃; the time of the boronization treatment is 0.5 to 3 hours.
10. Use of the non-noble metal hydrogen-analyzing electrocatalyst based on structural nanocrystallization combined with synergistic modification according to any one of claims 1 to 4 for hydrogen production by electrolytic water splitting.
Background
Fossil energy is an important material basis for building modern civilization of human beings, but the fossil energy is becoming a problem source for restricting the sustainable development of human society nowadays. As a clean and efficient secondary energy carrier, the large-scale industrial application of the hydrogen is expected to fundamentally solve the global problems of energy shortage, environmental pollution and the like and realize the sustainable development of the human society. Promoting the industrial application of hydrogen energy requires constructing a complete hydrogen energy industrial chain including the links of hydrogen production, hydrogen storage, hydrogen utilization and the like, wherein the hydrogen production is the source. The existing scale hydrogen production method mainly comprises three types of methane reforming, coal gasification and water electrolysis, but the former two hydrogen production technologies are seriously dependent on fossil energy and do not have sustainable development property. The water electrolysis hydrogen production belongs to a clean hydrogen production technology, and the water electrolysis hydrogen production can be fundamentally rid of the dependence of fossil fuel by utilizing the electric energy generated by primary renewable energy sources to dissociate water; meanwhile, a feasible scheme is provided for the effective utilization of primary renewable energy. The water electrolysis relates to two half reactions of cathodic hydrogen evolution and anodic oxygen evolution, the research and development of a high-activity electrocatalyst is a core subject of the development of water electrolysis technology by reducing reaction overpotential to improve energy efficiency.
Noble metal Pt is a well-known high-activity hydrogen evolution electrocatalyst, but the high material cost and the resource scarcity seriously restrict the large-scale application of the noble metal Pt. In recent years, the development of novel non-noble metal catalysts and the realization of excellent catalytic performance while reducing material costs have become a mainstream trend in the field of electrolytic water technology. According to the reports of the literatures, various types of materials such as 3d transition metal oxides, carbides, nitrides, phosphides, sulfides, selenides and borides have good electrocatalytic hydrogen evolution activity, and the catalytic performance of the materials can be effectively improved through modification strategies such as structural nanocrystallization, defect regulation and component modulation. However, in general, the non-noble transition metal electrocatalysts still have the defects of over-high overpotential of hydrogen evolution reaction, poor long-term working stability and the like. Therefore, the development of advanced design strategies of cheap metal catalysts is still a key problem to be solved urgently in the process of promoting the practicability of the electrolytic water technology.
Transition metal borides have a wide application prospect in the electrochemical field, however, the lack of advanced synthesis technology has made their development in the field of electrolyzed water still impossible. At present, transition metal boride is mainly prepared by chemical plating and high-temperature sintering methods, but too fast reaction kinetics or too high reaction temperature are not beneficial to fine regulation and control of a nano structure, and a large amount of energy consumed by the high-temperature sintering method cannot meet the requirement of industrial production [ chem.Rev.113(2013)7981-8065 ]. Therefore, there is an urgent need for a method for preparing transition metal boride which is easy and controllable and can be mass-produced.
Disclosure of Invention
Aiming at the defects and shortcomings of the prior art, the invention mainly aims to provide a non-noble metal hydrogen evolution electrocatalyst based on structural nanocrystallization combined with synergistic modification. The catalyst has high intrinsic activity, abundant active sites and good conductivity, can efficiently and stably catalyze electrolysis water hydrogen evolution reaction under an alkaline condition, and has comprehensive catalytic performance close to that of a noble metal Pt catalyst.
Another object of the present invention is to provide a method for preparing the above non-noble metal hydrogen evolution electrocatalyst based on structural nanocrystallization combined with synergistic modification. The method has the advantages of easily available raw materials, simple operation, controllable reaction and convenient mass production.
The invention further aims to provide the application of the non-noble metal hydrogen analysis electrocatalyst based on structural nanocrystallization and synergistic modification in hydrogen production through water decomposition.
The purpose of the invention is realized by the following technical scheme:
the catalyst consists of a metal boride active phase, an oxide matrix phase and a carrier, wherein the metal boride active phase is distributed on the surface of the oxide matrix phase in a nanoparticle form, and the oxide matrix phase is loaded on the carrier.
Preferably, the metal boride active phase is a transition group metal boride, and the oxide matrix phase is a transition group metal oxide; more preferably, the transition metal means one or a combination of several of Co, Ni, W, Mo, and the like.
The carrier is selected from foamed metal, metal mesh, ion exchange resin, molecular sieve or porous carbon material; more preferably foamed cobalt.
Preferably, the metal boride active phase exists in an amorphous form, and the particle size is 3-15 nm.
Preferably, the oxide matrix phase is present in amorphous or nanocrystalline form; the oxide matrix phase contains oxygen vacancies and has a nano-porous structure, and the size of the nano-pores is 2-10 nm.
The preparation method of the non-noble metal hydrogen evolution electrocatalyst based on structural nanocrystallization combination synergistic modification comprises the following preparation steps:
(1) adding a carrier material into an aqueous solution containing a transition metal salt and a precipitator, and growing a metal oxide precursor with a nano structure on the surface of the carrier material through a hydrothermal reaction;
(2) cleaning and drying the metal oxide precursor obtained in the step (1), and then carrying out high-temperature heat treatment in an inert atmosphere; so as to increase the structural stability and performance stability of the catalyst material;
(3) and (3) carrying out boronization treatment on the metal oxide precursor subjected to heat treatment in the step (2) (precipitating a metal boride active phase on the surface of the metal oxide in situ, and simultaneously obtaining an oxide matrix rich in a defect structure and having a nano porous structure), thus preparing the non-noble metal hydrogen evolution electrocatalyst based on structural nanocrystallization combined synergistic modification.
Preferably, the transition metal salt in step (1) is at least one of halide, nitrate, sulfate, sulfamate, acetate or oxygen-containing or oxygen-free acid salt of transition metal;
preferably, the transition group metal in step (1) refers to one or a combination of several of Co, Ni, W or Mo;
preferably, the precipitant in step (1) is at least one selected from sodium molybdate, sodium tungstate, ammonia water, urea and ammonium molybdate; more preferably sodium molybdate.
Preferably, the concentration of the transition metal salt in the step (1) is 0.0001-0.2M;
preferably, the concentration of the precipitating agent in the step (1) is 0.0001-0.3M;
preferably, the hydrothermal reaction temperature in the step (1) is 90-180 ℃; the time is 3-10 h;
preferably, the inert atmosphere in the step (2) is argon;
preferably, the temperature of the high-temperature heat treatment in the step (2) is 250-550 ℃; the time of the high-temperature heat treatment is 1-5 h.
Preferably, the boronizing step in step (3) is to dip the heat-treated metal oxide precursor into the solution containing NaBH4And carrying out boronization treatment on the mixed solution of NaOH.
Further preferably, the solvent of the mixed solution is a mixed solvent of ethylene glycol and deionized water; the proportion of ethylene glycol to deionized water in the mixed solvent is 0/1-4/1;
more preferably, the concentration of NaOH in the mixed solution is 0.05M-0.5M; NaBH in the mixed solution4The concentration of (A) is 0.5M to 5M.
Further preferably, the boronizing temperature is 25-95 ℃; the time of the boronization treatment is 0.5 to 3 hours.
The non-noble metal hydrogen analysis electrocatalyst based on structural nanocrystallization combination synergistic modification is applied to hydrogen production by electrolytic water decomposition.
The design principle of the invention is as follows:
for an electrocatalyst, the three elements that affect its apparent catalytic activity are: intrinsic activity, number of active sites and conductivity. The traditional electrocatalyst only focuses on one or two aspects, and the three elements of the catalyst provided by the invention are simultaneously optimized in the design idea, and a simple, easy and controllable preparation method is provided for realizing. Firstly, growing a metal oxide precursor which contains a catalyst active component and has a high specific surface area on the surface of a carrier material by a hydrothermal method, and laying a material composition and structural foundation for synthesizing a high-performance catalyst; subsequently, high-temperature heat treatment is carried out in an inert atmosphere to increase the structural stability and the performance stability of the catalyst material; finally, the boride active phase is selectively precipitated by regulating and controlling the boronizing treatment conditions, so that the boride active phase is distributed on the surface of the oxide matrix in the form of nano particles, and the in-situ compounding of the two phases is realized. On one hand, the metal boride precipitated in situ and an oxide matrix are combined to construct a synergistic catalytic active site, wherein the oxide promotes the dissociation of water molecules, the metal boride provides a hydrogen atom composite desorption active site, and the metal boride and the oxide matrix synergistically act to improve the reaction efficiency of alkaline water hydrogen evolution; on the other hand, the metal boride having metalloid conductivity coacts with oxygen defects introduced by partial reduction of the oxide matrix, contributing to improvement of the conductivity of the catalyst material; in addition, the precursor material of the hydrothermal synthesis contains a large amount of crystal water, and a dehydration reaction of the crystal water during the heat treatment process can form a large amount of nano holes, which helps to further increase the specific surface area of the material, thereby providing more active sites. In conclusion, the hydrogen evolution electrocatalyst provided by the invention has high intrinsic activity, abundant active sites and good conductivity.
The invention has the advantages and beneficial effects that:
(1) the method and the material provided by the invention have the characteristics of simultaneously optimizing three factors of intrinsic activity, active site number and conductivity. On one hand, the metal boride active phase is selectively precipitated by regulating and controlling the boronizing treatment conditions, and then combined with the matrix oxide to construct a synergistic catalytic active site; on the other hand, the metal boride with metalloid conductivity after the boronizing treatment and oxygen defects introduced due to the reduction of the oxide matrix part contribute to the improvement of the conductivity of the catalyst material; in addition, a large number of nano holes are generated in the precursor material due to dehydration in the heating process, so that the mass transfer performance of the catalyst can be further improved while more active sites are provided.
(2) The preparation method has the advantages of easily available raw materials, simple process, controllable reaction and convenient mass production.
(3) The non-noble metal hydrogen evolution electrocatalyst based on structural nanocrystallization combined synergistic modification can efficiently catalyze electrolysis water hydrogen evolution reaction under alkaline condition, and has excellent stability, and the comprehensive catalytic performance is close to that of a noble metal Pt catalyst.
Drawings
FIG. 1 is a sample CoMoO in a hydrothermal state in example 14·nH2O/CF, thermally treated sample CoMoO4Co-Mo-B/CoMoO of/CF and boronized samples4-xX-ray diffraction pattern of/CF.
FIG. 2 shows CoMoO as a hydrothermal sample in example 1 (a)4·nH2O/CF (b) thermally treated sample CoMoO4(c) boronized samples Co-Mo-B/CoMoO4-xA scanning electron microscope topography of/CF.
FIG. 3 is CoMoO of a sample in a heat-treated state in example 14(a) selected area electron diffraction pattern of (a) high resolution electron micrograph of (B), and boronized sample Co-Mo-B/CoMoO4-x(c) selected area electron diffraction pattern of/CF (d) high resolution electron micrograph.
FIG. 4 is the sample Co-Mo-B/CoMoO after boronization in example 14-xX-ray photoelectron spectrum of/CF.
FIG. 5a is the sample Co-Mo-B/CoMoO after boronization in example 14-xthe/CF and reference samples CF, CoMoO4·nH2O/CF、CoMoO4Comparison graph of hydrogen evolution reaction polarization curves of/CF and Pt/C.
FIG. 5B is the sample Co-Mo-B/CoMoO after boronization in example 14-xthe/CF and reference samples CF, CoMoO4·nH2O/CF、CoMoO4Current densities of/CF and Pt/C are plotted against potential sweep rate.
FIG. 5c is the sample Co-Mo-B/CoMoO after boronization in example 14-xthe/CF and reference samples CF, CoMoO4·nH2O/CF、CoMoO4The impedance spectrum test results of/CF, Pt/C under open circuit potential.
FIG. 6 is the sample Co-Mo-B/CoMoO after boronization in example 14-xDurability test result of/CF.
FIG. 7 is the sample Co-Mo-B/CoMoO after boronization in example 14-xThe shape and appearance of a scanning electron microscope (a) and the selected area electron diffraction pattern and the high-resolution electron microscope (c) of the/CF after 100-hour durability test.
FIG. 8 is the Co-Mo-B/CoMoO sample after boronization in example 24-xThe shape and appearance of NF are shown by a scanning electron microscope.
FIG. 9 shows an embodimentSample Co-Mo-B/CoMoO after boronization in 24-xX-ray diffraction pattern of/NF.
FIG. 10 is the Co-Mo-B/CoMoO sample after boronization in example 24-xHigh resolution electron micrograph of/NF.
FIG. 11 is the sample Co-Mo-B/CoMoO after boronization in example 24-xThe X-ray photoelectron spectrum of/NF.
FIG. 12 is the sample Co-Mo-B/CoMoO after boronization in example 24-xThe polarization curve of hydrogen evolution reaction of the/NF (a) and the reference sample Pt/C is compared with the durability test result chart of the (b).
FIG. 13 is sample Co-W-B/CoWO after boronation in example 34-xThe polarization curve of hydrogen evolution reaction of the/CF (a) and the reference sample Pt/C is compared with the graph of the durability test result of the graph of the (b).
FIG. 14 is the sample Ni-Mo-B/NiMoO after boronization in example 44-xThe polarization curve of hydrogen evolution reaction of the/CF (a) and the reference sample Pt/C is compared with the graph of the durability test result of the graph of the (b).
FIG. 15 shows the samples Ni-Co-B/NiCoO after boronization in example 5xThe polarization curve of hydrogen evolution reaction of the/CF (a) and the reference sample Pt/C is compared with the graph of the durability test result of the graph of the (b).
Detailed Description
The present invention is specifically described below with reference to examples, but the embodiments and the scope of the present invention are not limited to the following examples.
The present invention is described in detail below with reference to specific examples.
Example 1
Co-Mo-B/CoMoO4-xSynthesis, structure and catalytic performance of/CF catalyst
Preparing a catalyst:
(1) foamed Cobalt (CF) is used as a carrier, the thickness of the foamed Cobalt (CF) is 1.80mm, and the surface density of the foamed Cobalt (CF) is 650g/m2The aperture is 0.20-0.80 mm. Foamed cobalt (1X 4 cm)2) Ultrasonic cleaning with ethanol for 10 min, activating with 1M hydrochloric acid solution for 5 min, and ultrasonic cleaning with deionized water for 10 min, and mixing with 30mL of solution containing Co (NO)3)2·6H2O(0.02M)、Na2MoO4·2H2A solution of O (0.01M) in deionized water was placed in a 50mL volume hydrothermal reactorTreating at 150 deg.C for 6 hr, naturally cooling to room temperature, cleaning, vacuum drying at 60 deg.C for 2 hr to obtain hydrothermal CoMoO sample4·nH2O/CF。
(2) Mixing 1X 2cm2The hydrothermal sample is placed in the middle of a quartz boat, heated to 400 ℃ in an argon atmosphere at the heating rate of 5 ℃/min, subjected to constant temperature treatment for 2 hours and then cooled to room temperature to obtain a thermal treatment sample CoMoO4/CF。
(3) The heat-treated sample was immersed in 50ml of a solution containing NaOH (0.25M) and NaBH4Reacting in 2.5M ethylene glycol/water mixed solution (ratio 1: 1) at the constant temperature of 90 ℃ for 1 hour to obtain a sample, fully cleaning the sample, and performing vacuum drying at the temperature of 60 ℃ for 2 hours to obtain the target catalyst Co-Mo-B/CoMoO4-x/CF。
Characterization of phase/structure/elemental chemistry of the catalyst:
the X-ray diffraction and scanning electron micrographs of the hydrothermal sample and the heat-treated sample obtained in this example are shown in fig. 1 and fig. 2, respectively. According to XRD analysis (FIG. 1), the synthesized hydrothermal sample was CoMoO4·nH2O crystal phase, the heat treated sample is CoMoO4A crystalline phase. The observation of a scanning electron microscope (a and b in fig. 2) shows that the hydrothermal sample is a 3D nano flower ball structure formed by self-assembly of nano sheets, the appearance of the nano flower ball is not obviously changed after high-temperature heat treatment, but the observation of a transmission electron microscope (a and b in fig. 3) shows that a large number of nano holes are generated on the nano sheets, and the aperture size is 2-4 nm.
Scanning electron microscope observation (fig. 2c) shows that the morphology of the nano flower ball is still basically maintained after the heat-treated sample is subjected to boronization treatment, but the nano sheet is thinned and more holes are generated. According to XRD analysis (figure 1), the target catalyst after boronization treatment is in an amorphous or nanocrystalline phase. Transmission electron microscopy (c, d in FIG. 3) further confirmed the presence of amorphous phase in the target catalyst, but co (OH) was also found as a by-product2And (4) generation of a crystalline phase.
According to X-ray photoelectron spectroscopy (FIG. 4), the sample in the heat-treated state was Co alone2+And Mo6+A signal; after boronization, additional Co was present in the samples0、Mo0、Mo4+And Mo5+Signal, and B element in the boronized sample is present0A signal. Co was observed0Relative to the standard sample, Mo0And B0Positive shift relative to the standard sample occurs, thereby demonstrating the formation of a Co-Mo-B alloy in the target catalyst; mo was observed4+And Mo5+Signal, and defect oxygen signal, thereby evidencing the presence of defect structure oxides in the target catalyst. Based on the above analysis, it was confirmed that the target catalyst was foamed cobalt-supported Co-Mo-B/CoMoO4-xA catalyst.
Electrocatalytic performance test of the catalyst:
the results of the hydrogen evolution reaction polarization curve test (FIG. 5a) show that Co-Mo-B/CoMoO4-xthe/CF catalyst has excellent hydrogen evolution reaction electrocatalytic activity, and can reach 10mA/cm in 1.0M potassium hydroxide alkali solution only by 55mV hydrogen evolution overpotential2The catalytic activity of the catalyst is close to that of a noble metal Pt/C catalyst.
FIG. 5B shows the Co-Mo-B/CoMoO target catalyst4-xCompared with a hydrothermal sample and a heat treatment sample, the double-electric-layer capacitance of the target catalyst is respectively improved by 2.5 times and 6.5 times, namely the electrochemical specific surface area is respectively improved by 2.5 times and 6.5 times, and the obvious improvement of the electrochemical specific surface area is due to dehydration reaction in the heat treatment process and reduction reaction in the boronization process; according to the impedance spectrum test result (figure 5c), the charge transfer resistance of the target catalyst is greatly reduced compared with that of the hydrothermal sample and the thermal treatment sample, and the stress is caused by in-situ precipitation of Co-Mo-B phase with metal characteristics and CoMoO4-xThe presence of defective structures in the substrate.
FIG. 6 shows Co-Mo-B/CoMoO4-xThe stability test result of the/CF catalyst shows that the activity of the catalyst is not obviously declined after 100-hour constant current measurement, which indicates that the catalyst has excellent stability.
FIG. 7 shows Co-Mo-B/CoMoO4-xThe phase/microstructure result of the/CF catalyst after 100-hour durability test shows that the morphology and the phase structure of the catalyst are not obviously changed,the catalyst has good structural stability.
Example 2
Co-Mo-B/CoMoO4-xSynthesis, structure and catalytic performance of/NF catalyst
Preparing a catalyst:
in the synthesis process of this example, only Cobalt Foam (CF) was replaced with Nickel Foam (NF), and the preparation conditions were otherwise the same as in example 1.
Characterization of phase/structure/elemental chemistry of the catalyst:
the observation of a scanning electron microscope (figure 8) shows that the target catalyst is a 3D nano flower ball structure consisting of nano sheets, and a large number of holes are formed in the nano sheets.
The XRD results show (fig. 9) that the target catalyst is amorphous or nanocrystalline.
The presence of an amorphous phase in the target catalyst was further confirmed by transmission electron microscopy (FIG. 10), but Co (OH) was also found as a by-product2And (4) generation of a crystalline phase.
XPS results (FIG. 11) indicate the formation of Co-Mo-B alloy and the presence of defect structure oxides in the target catalyst, thus demonstrating that the target catalyst is foamed nickel supported Co-Mo-B/CoMoO4-xA catalyst.
Electrocatalytic performance test of the catalyst:
the results of the hydrogen evolution reaction polarization curve test (a in FIG. 12) show that Co-Mo-B/CoMoO4-xthe/NF catalyst has excellent hydrogen evolution reaction electrocatalytic activity, and can reach 10mA/cm in 1.0M potassium hydroxide alkali solution only by 58mV hydrogen evolution overpotential2Current density of (d); the 24-hour constant current durability test result (b in fig. 12) shows that the activity of the catalyst is not obviously degraded, which indicates that the catalyst has excellent stability.
Example 3
Co-W-B/CoWO4-xSynthesis, structure and catalytic performance of/CF catalyst
Preparing a catalyst:
in the synthesis method of this example, only Na is added2MoO4·2H2Changing O to Na2WO4·2H2O, the remainderThe preparation conditions were identical to those of example 1.
Electrocatalytic performance test of the catalyst:
the results of the hydrogen evolution reaction polarization curve test (a in FIG. 13) show that Co-W-B/CoWO4-xthe/CF catalyst has excellent hydrogen evolution reaction electrocatalytic activity, and can reach 10mA/cm in 1.0M potassium hydroxide alkali solution only by 77mV hydrogen evolution overpotential2Current density of (d); the 24-hour constant current durability test result (b in fig. 13) shows that the activity of the catalyst is not obviously degraded, which indicates that the catalyst has excellent stability.
Example 4
Ni-Mo-B/NiMoO4-xSynthesis, structure and catalytic performance of/CF catalyst
Preparing a catalyst:
in the synthesis method of this example, similarly to example 1, only the difference is in the oxide precursor.
The oxide precursor is synthesized by the following method: foamed cobalt (1X 4 cm)2) Ultrasonic cleaning with ethanol for 10 min, activating with 1M hydrochloric acid solution for 5 min, and ultrasonic cleaning with deionized water for 10 min, and mixing with 36mL Ni (NO)3)2·6H2O(4mmol)、(NH4)6Mo7O24·4H2O(1mmol)、CO(NH2)2Putting (10mmol) deionized water solution into a hydrothermal kettle with the volume of 50mL, carrying out constant temperature treatment at 150 ℃ for 18 hours, naturally cooling to room temperature, fully cleaning the prepared sample, and carrying out vacuum drying at 60 ℃ for 2 hours to obtain an oxide precursor NiMoO4/CF。
Electrocatalytic performance test of the catalyst:
the results of the hydrogen evolution reaction polarization curve test (a in FIG. 14) show that Ni-Mo-B/NiMoO4-xthe/CF catalyst has excellent hydrogen evolution reaction electrocatalytic activity, and can reach 10mA/cm in 1.0M potassium hydroxide alkali solution only by 62mV hydrogen evolution overpotential2Current density of (d); the 15-hour constant current durability test result (b in fig. 14) shows that the activity of the catalyst is not obviously degraded, which indicates that the catalyst has excellent stability.
Example 5
Ni-Co-B/NiCoOxSynthesis, structure and catalytic performance of/CF catalyst
Preparing a catalyst:
in the synthesis method of this example, similarly to example 1, only the difference is in the oxide precursor.
The oxide precursor is synthesized by the following method: foamed cobalt (1X 4 cm)2) Ultrasonic cleaning with ethanol for 10 min, activating with 1M hydrochloric acid solution for 5 min, and ultrasonic cleaning with deionized water for 10 min, and mixing with 30mL Ni (NO)3)2·6H2O(3mmol)、Co(NO3)2·6H2O(3mmol)、CO(NH2)2And (12mmol) deionized water solution is placed in a hydrothermal kettle with the volume of 50mL, is subjected to constant temperature treatment at 120 ℃ for 8 hours, is naturally cooled to room temperature, is fully cleaned, is subjected to vacuum drying at 60 ℃ for 2 hours, and is calcined at 300 ℃ for 2 hours in argon gas to obtain an oxide precursor Ni-Co-O/CF.
The results of the hydrogen evolution reaction polarization curve test (a in FIG. 15) show that Ni-Co-B/NiCoOxthe/CF catalyst has excellent hydrogen evolution reaction electrocatalytic activity, and can reach 10mA/cm in 1.0M potassium hydroxide alkali solution only by 83mV hydrogen evolution overpotential2Current density of (d); the 24-hour constant current durability test result (b in fig. 15) shows that the activity of the catalyst is not obviously degraded, which indicates that the catalyst has excellent stability.
The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.
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