61 results about "Mass activity" patented technology

The invention discloses a 3d transition metal M-rare earth metal R bi-component doped carbon-supported Pt catalyst as well as a preparation method and application thereof, relates to a catalyst taking doped carbon as a carrier to support Pt as well as a preparation method and application thereof, and aims to solve the problem that the existing Pt / C catalyst is poor in catalytic activity and stability. Wherein M is Fe, Co, Ni or Zn, and R is Ce, Nd or Gd. The preparation method comprises the following steps: carrying out complexing growth on M and R ions and a nitrogen source ligand on the carbon surface, and then carrying out high-temperature carbonization to obtain an M-R bi-component doped carbon carrier; the preparation method comprises the following steps: preparing an M-R two-component doped carbon-carbon supported Pt catalyst by using a microwave reduction method, then loading Pt by using a microwave reduction method to obtain the M-R two-component doped carbon-carbon supported Pt catalyst, the mass activities of Pt / Fe-Ce-NC and Pt / Co-Ce-NC are respectively 0.27 A / mgPt and 0.22 A / mgPt and are 2.8 times and 2.3 times that of Pt / C, and the M-R two-component doped carbon-carbon supported Pt catalyst can be used in the field of proton exchange membrane fuel cells.

The invention belongs to the technical field of electrochemistry, and provides a monatomic iridium-based alloy cluster catalyst and a preparation method and electrocatalysis application thereof, and the preparation method comprises the following steps: low-pressure gas-phase capillary filling: mixing an iridium organic metal precursor, a dopant metal organic precursor, a microporous carrier material and a solvent, and drying to obtain mixed powder, the mixed powder is placed in an ampoule bottle with a certain vacuum degree and sealed, then the ampoule bottle is placed in a rotary drying oven for high-temperature heat treatment, and powder a is obtained; temperature-controlled acid etching: mixing the powder a and an acid solution for reaction in the environment of protective gas to obtain black powder; the black powder is placed in H2 / Ar mixed gas for programmed heat treatment, and the monatomic iridium-based alloy cluster catalyst is obtained. The monatomic iridium-based alloy cluster catalyst prepared by the method provided by the invention shows mass activity and catalytic durability which are obviously superior to those of commercial platinum carbon in alkaline hydroxide catalysis, and has a practical application prospect.

The invention discloses a Ti-RuO2 acidic oxygen evolution catalyst based on a strain modulation strategy and a preparation method of the Ti-RuO2 acidic oxygen evolution catalyst, and belongs to the technical field of hydrogen production catalysts. The preparation method comprises the following steps: S1, mixing TiO2 with an acidic solution, adjusting the pH value, and dispersing to obtain a TiO2 dispersion liquid; s2, adding soluble Ru salt into the TiO2 dispersion liquid under an ice bath condition, and stirring to obtain a mixed solution; s3, mixing and stirring the mixed solution and an alkaline solution to adjust the pH value, and then freeze-drying to obtain a precursor; and S4, immediately performing high-temperature pyrolysis on the precursor, and then quickly taking out and cooling to obtain the Ti-RuO2 acidic oxygen evolution catalyst based on the strain modulation strategy. The mass activity of the obtained catalyst at 1.53 V is 6 times that of commercial RuO2, and meanwhile, the catalyst has the stability of 830 h at the current density of 10 mA cm <-2 >.

The invention discloses a Ru / Ni-3DONMC catalyst as well as a preparation method and application thereof, and relates to the technical field of new energy materials and electrochemical catalysis. According to the invention, self-designed ordered SiO2 microspheres are self-assembled as a template, a nitrogen-doped carbon carrier with a three-dimensional ordered hierarchical pore structure is constructed, and a composite catalytic system with a multi-stage active center is successfully prepared by combining a bimetallic precursor adsorption impregnation and thermal reduction process. The catalyst disclosed by the invention shows excellent bifunctional catalytic performance in an alkaline medium; only 16 mV overpotential is needed in a hydrogen evolution reaction under the current density of 10 mA cm <-2 >, and the Tafel slope is as low as 40.54 mV / dec; and in a hydroxide reaction, the material has high limiting current density of 2.55 mA cm <-2 > and excellent mass activity. And it is powerfully proved that the intrinsic catalytic activity and long-term operation stability of the hydrogen-electricity reaction can be effectively improved through a monatomic-nanocluster cooperative regulation strategy.

The invention discloses a superfine medium-entropy nanoparticle catalyst for electrochemical oxidation of ethylene glycol and other micromolecules as well as a preparation method and application of the superfine medium-entropy nanoparticle catalyst. The catalyst comprises a superfine medium-entropy nano-particle metal material and a conductive substrate material, the superfine medium-entropy nano-particle metal material comprises copper metal and at least two precious metals, and the catalyst has outstanding catalytic ability. The preparation method of the catalyst is simple and convenient, and only the superfine medium-entropy nanoparticle metal material needs to be synthesized through a solvothermal method and is loaded on the conductive substrate material; the temperature of the whole synthesis process is lower than 200 DEG C, so that the problems of high cost, high energy consumption, poor stability, large potential safety hazard and the like in the traditional synthesis method are solved. The superfine medium-entropy nanoparticle catalyst prepared by the invention shows excellent performance in oxidation of micromolecules such as electro-catalysis ethylene glycol and the like. By taking ethylene glycol electrooxidation as an example, the Pb-CuPtPd MEANs-C can efficiently and stably convert ethylene glycol into glycollic acid, the mass activity of the Pb-CuPtPd MEANs-C under 0.9 V vs.RHE reaches up to 14 A mg <-1 > PtPd, and the Faraday efficiency (FEGA) of glycollic acid production is 82.3%.

The invention belongs to the technical field of electrochemical catalytic materials, and relates to an efficient non-iridium nickel-based catalyst and a preparation method thereof. Comprising a nitrogen-sulfur bifunctional in-situ doped and modified nickel-cobalt layered double hydroxide nanosheet, 2, 5-dihydroxy terephthalamide, a conductive carbon carrier, a pore-forming agent, a surface wetting agent and a cross-linking agent. The nickel-cobalt layered double hydroxide is prepared by carrying out hydrothermal reaction and calcination treatment on nickel nitrate hexahydrate, cobalt nitrate hexahydrate, thiourea and melamine under an alkaline condition, and synergistic doping of nitrogen and sulfur bifunctional groups is realized; organic-inorganic interface interaction is introduced into 2, 5-dihydroxy terephthalamide, so that the structural stability of the material is enhanced. According to the invention, the current density, the mass activity, the gas production volume, the stability and the turnover performance are obviously improved. According to the invention, the defects of insufficient conductivity, limited active sites and poor cycling stability of the existing nickel-cobalt-based catalyst are effectively overcome, and a new thought is provided for developing a low-cost and high-performance electrochemical catalyst.

The present invention relates to the field of fuel cell technology, and in particular to a method for preparing an ultra-low platinum cathode catalyst for fuel cells. The method for preparing an ultra-low platinum cathode catalyst for fuel cells of the present invention comprises the following steps: pyrolyzing nitrogen-containing MOFs to prepare a catalyst carrier, mixing the carrier with a platinum precursor for reaction, and then calcining in an inert atmosphere and an ammonia atmosphere in two steps to obtain a nitrogen-doped carbon catalyst loaded with a platinum-cobalt intermetallic compound. The catalyst carrier prepared by the present invention has a hierarchical pore structure, and the loaded platinum-cobalt intermetallic compound particles have a small particle size and are uniformly loaded. The precious metal loading of the prepared catalyst can be adjusted according to the ratio of different raw materials. The cathode catalyst has a higher power density and mass activity in a fuel cell with an ultra-low platinum load than a commercial Pt / C catalyst with the same platinum loading.

A phosphide-induced PtM ordered alloy composite catalyst and its preparation method and application, which relates to a composite catalyst and its preparation method and application, and solves the technical problems of low catalytic activity and poor stability of existing Pt-based catalysts. The catalyst of the present invention is composed of an ordered PtM alloy and a M x P is uniformly loaded on a carbon support, and the ordered PtM alloy is composed of M x The catalyst is obtained by inducing a high-temperature phase transition of P; wherein M is Co, Fe, or Ni, and x = 0.5 to 3. It is obtained by impregnating the surface of a carbon support with Pt, P, and M precursors, evaporating them to dryness, and then annealing and grinding them in an inert gas. The mass activity of the catalyst of the present invention is 0.384 to 0.321 mA / μg. Pt , approximately 3.4 times that of commercial 10% Pt / C. PtCo-Co2P / C exhibited a half-wave potential decay of only 5mV after 30,000 cycles, with a mass activity decay rate of 13.44%. It can be used in fuel cell applications.

The present invention provides a semiconductor laser element provided with a hydrogen and oxygen evolution layer, which relates to the technical field of semiconductor optoelectronic devices. It sequentially includes a substrate, a lower confinement layer, a lower waveguide layer, an active layer, an upper waveguide layer, an electron blocking layer, and an upper confinement layer from bottom to top. A hydrogen and oxygen evolution layer is provided above the upper confinement layer, which is used to adsorb hydrogen atoms and oxygen atoms in the upper confinement layer and desorb them. By means of a heterointerface, the overpotential of the hydrogen and oxygen evolution reaction is reduced, and the reaction kinetics is accelerated. By an electrochemical method, hydrogen atoms and oxygen atoms in the upper confinement layer are adsorbed under an externally applied bias voltage, and the hydrogen atoms and oxygen atoms are efficiently desorbed, reducing the oxidation of Mg on the interface and surface. The mass activity of hydrogen and oxygen evolution is increased by more than 5 times compared with that of traditional Pt / C, forming H2 and O2 to be discharged from the surface, increasing the ionization rate of the p-type doping element in the upper confinement layer and reducing the acceptor activation energy, and increasing the hole concentration in the upper confinement layer.

A fuel cell catalyst including a conductive carrier and core-shell nanoparticles supported on the carrier. The core includes platinum and a transition metal and the shell includes a secondary metal. An electrochemical specific activity measured at a voltage of 0.05 V to 1.05 V (vs. RHE) in a potential range, at a scan rate of 5 mV / s and a rotation rate of 1,600 rpm in an O2-saturated 0.1 M HClO4 electrolyte solution is 0.3 mA / cm2 to 0.6 mA / cm2, and a mass activity is 0.05 mA / μg to 0.08 mA / μg.

This invention relates to fuel cell catalysts, their preparation methods, and fuel cells comprising the same. The fuel cell catalyst includes a conductive support and core-shell nanoparticles supported on the support. The core comprises platinum and a transition metal, and the shell comprises a dissimilar metal. The electrochemical specific activity, measured in an O2-saturated 0.1M HClO4 electrolyte solution at a scan rate of 5 mV / s and a rotation rate of 1,600 rpm within a potential range of 0.05 V to 1.05 V (vs. RHE), is 0.3 mA / cm². 2 Up to 0.6 mA / cm 2 And the mass activity is 0.05 mA / μg to 0.08 mA / μg.

The invention relates to the field of electrocatalysts, in particular to an iridium dioxide / molybdenum disulfide / carbon matrix heterostructure electrocatalyst, a preparation method and application. According to the iridium dioxide / molybdenum disulfide / carbon matrix heterostructure electrocatalyst provided by the invention, IrO2 and MoS2 in a heterojunction structure can be mutually adjusted, so that the electrocatalyst has a higher electron transfer rate, excellent hydrophilicity, proper OH * adsorption capacity and a higher deprotonation rate, has better electrochemical performance in catalytic electrolysis of water, and can be used for preparing a high-performance electrocatalyst. In an oxygen evolution reaction, the iridium oxide shows performance far superior to that of commercial iridium oxide, and has relatively low overpotential and relatively high quality activity; good electrochemical performance is shown in the aspect of hydrogen precipitation and is superior to that of commercial Pt / C; and the used material shows relatively low decomposition voltage when being applied to electrolyzed water. Therefore, the IrO2 / MoS2 / CNT heterostructure catalyst can be widely and deeply applied to electrolyzed water.

The invention provides a gallium oxide-palladium metal alkene catalyst and a preparation method thereof, and belongs to the technical field of fuel cells, the gallium oxide-palladium metal alkene catalyst comprises palladium metal alkene with a two-dimensional lamellar structure and gallium oxide clusters supported on the surface of the palladium metal alkene in an atomic-scale dispersion mode, and the method comprises the following steps: dissolving a palladium source and a gallium source in a solution formed by formamide and N, N-dimethylformamide; the preparation method comprises the following steps: dissolving in a mixed solvent consisting of N, N-dimethylformamide under stirring to obtain a precursor solution; under a low-temperature condition, carbon monoxide gas is introduced into the precursor solution for pretreatment; carrying out constant-temperature reaction on the pretreated solution at 160 + / -10 DEG C; the gallium oxide-palladium metal alkene catalyst is obtained by sequentially cleaning and separating a product obtained after the reaction, due to the existence of gallium oxide clusters, the electronic structure of Pd can be adjusted, the reaction is accelerated in the oxygen reduction reaction process, meanwhile, the preparation process is simple, the half-wave potential is high, and the quality activity is high.

This paper discloses a 3d transition metal M-rare earth metal R bicomponent carbon-supported Pt catalyst, its preparation method, and its application. It relates to the catalyst supported on carbon doped with Pt, its preparation method, and its application. This catalyst aims to address the poor catalytic activity and stability of existing Pt / C catalysts. The catalyst consists of Pt nanoparticles supported on an M-R bicomponent carbon support, where M is Fe, Co, Ni, or Zn, and R is Ce, Nd, or Gd. Preparation method: M and R ions are complexed with a nitrogen source ligand on a carbon surface and then carbonized at high temperature to obtain the M-R bicomponent carbon support. Then, Pt is loaded using a microwave reduction method to obtain the M-R bicomponent carbon-supported Pt catalyst. The mass activities of Pt / Fe-Ce-NC and Pt / Co-Ce-NC are 0.27 and 0.22 A / mg, respectively. Pt It is 2.8 and 2.3 times that of Pt / C, and can be used in the field of proton exchange membrane fuel cells.

The application discloses a Ti-RuO2 acidic oxygen evolution catalyst based on a strain modulation strategy and a preparation method thereof, and belongs to the technical field of hydrogen production catalysts. The preparation method comprises the following steps: S1, mixing TiO2 with an acidic solution to adjust pH and then dispersing to obtain a TiO2 dispersion liquid; S2, adding the TiO2 dispersion liquid to a soluble Ru salt under ice bath conditions to stir to obtain a mixed solution; S3, mixing the mixed solution with an alkaline solution to stir to adjust pH, and then freeze-drying to obtain a precursor; and S4, immediately pyrolyzing the precursor at high temperature, and then quickly taking out to cool to obtain the Ti-RuO2 acidic oxygen evolution catalyst based on the strain modulation strategy. The mass activity of the obtained catalyst at 1.53V is 6 times that of a commercial RuO2, and the stability is 830h under a current density of 10mA cm ‑2 .

The invention belongs to the field of fuel cell catalyst preparation, and particularly relates to a superfine PtCo ordered nano-alloy catalyst and a preparation method and application thereof. The preparation method comprises the following steps: 1) preparing a ZIF precursor; 2) mixing and calcining the ZIF precursor, KCl and NH4Cl to obtain a carbon carrier; (3) loading the superfine Pt nano particles on the carbon carrier; (4) loading a Co source on a product obtained in the step (3); and 5) performing high-temperature annealing under the protection of reducing atmosphere and inorganic salt to obtain the PtCo ordered nano-alloy catalyst. According to the preparation method of the superfine PtCo ordered nano-alloy catalyst, controllable preparation of the high-dispersion Pt nano-alloy is realized through a two-step inorganic salt heat treatment method, a larger effective active area and higher catalyst mass activity are obtained, and a material basis is provided for reducing the manufacturing cost of a fuel cell membrane electrode.

The present invention provides a highly stable graphene-coated Pd-Zn alloy catalyst and a preparation method thereof. The present invention first utilizes a simple method to synthesize a carbon precursor with a three-dimensional structure; after loading a palladium salt on its surface, acetate is added as a small molecule modifier, and finally a graphene-coated Pd-Zn alloy catalyst is obtained by a one-step heat treatment, wherein the alloy particles are uniformly dispersed on the carbon support and have a particle size of less than 10 nm. The present invention is simple to operate, low in cost, and can be mass-produced, and the obtained catalyst has a unique graphene-coated structure, the alloy particles are bound by the graphite layer, which plays a role of physical isolation, reduces the shedding and aggregation of the catalyst in practical applications, prevents the disappearance of active sites, and improves the electrochemical performance of the catalyst as a whole. After 60,000 cycles of accelerated aging experiments, the mass activity loss rate of the catalyst is less than 5%, and has excellent stability.

The invention belongs to the technical field of catalysts, and particularly relates to a heterostructure catalyst as well as a preparation method and application thereof. The heterostructure catalyst comprises a carbon carrier and metal particles loaded on the carbon carrier, the metal particles comprise PdZn nano alloy and Co nano particles; and a heterojunction interface structure is arranged between the PdZn nano-alloy and the Co nano-particles. The PdZn alloy particles and the Co particles form a particle-particle heterostructure with a strong interface coupling effect, the EOR catalytic activity of the heterostructure catalyst is improved, the EOR catalytic activity is almost 10.7 times of the mass activity of a traditional Pd / C catalyst, and the catalyst can be applied to an anode catalyst of a direct ethanol fuel cell. Meanwhile, the method also has higher C1 pathway selectivity, effectively improves the utilization rate of the ethanol fuel, has a remarkable cost advantage, and can be used for manufacturing ethanol fuel cells.

A method for preparing a carbon-supported platinum-copper alloy catalyst for a proton exchange membrane fuel cell belongs to the field of fuel cells. The method involves fully impregnating a carbon support in a copper-containing solution, adding sodium hydroxide to adjust the solution pH, aging the solution, and then adding a reducing agent for full reduction to obtain carbon-supported cuprous oxide particles. The carbon-supported cuprous oxide particles are then fully impregnated in a platinum solution and the solution pH is adjusted, then transferred to a reactor, heated to 80-110°C, and hydrogen is introduced for pressurized hydrogen reduction to obtain a carbon-supported platinum-copper alloy catalyst. The carbon-supported platinum-copper alloy catalyst synthesized in two steps in an aqueous system has a mass activity greater than 0.6 A·mgPt ‑1 , which is superior to the quality activity of the mainstream platinum-carbon catalysts on the current market.

Aspects of the present disclosure generally relate to processes for forming electrodes comprising bimetallic catalysts and to processes for forming electrodes comprising trimetallic catalysts. In an aspect, a process for making an electrode comprising carbon-supported metal alloy nanoparticles is provided. The process includes applying a plurality of first voltage cycles to an initial electrode, the initial electrode including metal alloy nanoparticles that includes platinum and one or more Group 8-11 metals, the one or more Group 8-11 metals free of Pt; and a carbon source. The process further includes applying a plurality of second voltage cycles to form a final electrode, the metal alloy nanoparticles of the final electrode having an oxygen reduction reaction (ORR) mass activity that is greater than the ORR mass activity of the initial electrode.

The invention discloses a method for preparing a surface platinum-enriched high-entropy alloy hydrogen evolution electrocatalyst by an atomic layer deposition technology. According to the method, controllable deposition and uniform distribution of platinum atoms are realized by utilizing self-limiting reaction of atomic layer deposition. Compared with an existing heat treatment, pulse annealing, wet chemical epitaxy or replacement modification method, the method has the advantages that precise deposition of atomic-scale platinum can be achieved, the problems of high-entropy base surface precious metal agglomeration, non-uniform enrichment, uncontrollable diffusion and the like are solved, and therefore the precious metal utilization efficiency and the surface structure controllability are remarkably improved. Through verification, the surface regulation strategy enables the catalyst to show lower overpotential, faster dynamics and higher quality activity in a hydrogen evolution reaction. According to the technical route, a new method is provided for high-entropy alloy surface engineering, and a new thought is provided for constructing an electro-catalytic material with high activity and high precious metal utilization rate.

This invention relates to the field of proton exchange membrane water electrolysis technology, and discloses a method for testing the utilization rate of anode catalysts in PEM electrolyzers. The method includes: obtaining the intrinsic mass activity and intrinsic electrochemical active area; obtaining the apparent mass activity of the membrane electrode and the charge transport performance parameters of the membrane electrode catalyst layer; calculating a first parameter characterizing the degree of activity; obtaining the accessible electrochemical active area of ​​the membrane electrode catalyst layer under actual operating conditions, and calculating a second parameter characterizing the accessibility of active sites based on the intrinsic electrochemical active area; calculating theoretical charge transfer performance parameters based on the intrinsic electrochemical active area, and calculating a third parameter characterizing charge transport efficiency in combination with the charge transport performance parameters; comparing the relative magnitudes of the parameters to determine the root cause type. This invention achieves multi-dimensional quantitative evaluation of the utilization rate of anode catalysts in PEM electrolyzers and intelligent diagnosis of failure root causes.

The invention relates to the field of fuel cell nano material application, and discloses a PdCuNi medium-high entropy alloy catalyst for formic acid oxidation reaction and a preparation method thereof.The catalyst is composed of Pd, Cu and Ni, the atomic ratio of Pd to Cu to Ni is 50-55: 20-25: 20-25, the catalyst is of a three-dimensional porous nanowire structure, the average diameter of nanowires is 5-8 nm, the specific surface area (ECSA) is larger than or equal to 50 m / g, and the specific surface area (ECSA) is larger than or equal to 50 m / g. The three-dimensional porous structure catalyst prepared by a NaBH4 one-step reduction method has atomic-scale disordered arrangement, high specific surface area and optimized d-band center, and the catalytic activity (mass activity of 2.7 A / mg) and stability (10h performance retention rate of 82%) of formic acid oxidation reaction are remarkably improved. According to the PdCuNi medium-high-entropy alloy catalyst for formic acid oxidation reaction and the preparation method of the PdCuNi medium-high-entropy alloy catalyst, the power density of 153 mW / cm is achieved in a direct formic acid fuel cell, the PdCuNi medium-high-entropy alloy catalyst can be expanded to the fields of electro-catalysis hydrogen production and the like, and a new path is provided for design of an efficient palladium-based catalyst.

The invention discloses a Pt-MxP / M-N-C catalyst as well as a preparation method and application thereof, relates to a Pt-based catalyst as well as a preparation method and application thereof, and aims to solve the technical problems of poor activity and stability of the existing Pt-based catalyst. According to the catalyst, metal Pt and MxP are evenly compounded and supported on an M-N-C carrier, M-N-C is obtained through high-temperature pyrolysis of M-ZIF-8, Pt is obtained through a microwave ethylene glycol reduction method and supported on the M-N-C carrier, and MxP is obtained through phosphating aftertreatment of a phosphor salt precursor and the catalyst; m is Co, Zn or Ni; the preparation method comprises the following steps: supporting Pt on M-N-C by a microwave ethylene glycol method, and then carrying out high-temperature phosphating post-treatment to form MxP, thereby obtaining the Pt-MxP / M-N-C catalyst. Wherein the mass activity of the Pt-Co2P / Co-N-C catalyst reaches 0.213 mA / [mu] gPt, and the Pt-Co2P / Co-N-C catalyst can be used in the field of fuel cell catalysis.

The application discloses an Ir-doped WO3@TiN and a preparation method and application thereof, designs a composite carrier of WO3 and TiN, and effectively improves the catalytic effect of noble metal Ir. WO3 and TiN are combined as a carrier through a hydrothermal reaction, in the process, free Ti in the solution is doped into the position of W atoms, the number of oxygen vacancies in WO3 is increased, the electronic configuration of Ir is optimized, and the OER reaction is facilitated; in addition, a large number of pores are generated when the hexagonal rod structure WO3 is combined with the particle structure TiN, the diffusion of water and oxygen in the PEMWE process is promoted, compared with other single materials as a carrier, the Ir / WO3@TiN has more comprehensive advantages and higher structural dimension, and the activity and stability of the reaction are increased. The three-electrode test result shows that the Ir / WO3@TiN only needs an overpotential of 253 mV to reach 10 mA cm ‑2 , and the Tafel slope is only 47.35 mV dec ‑1 . The mass activity (MA) can reach 920.93 mA mgIr ‑1 at 1.53 V vs RHE.

The application discloses a kind of two-dimensional Pd nanosheet electrocatalysts rich in grain boundary and a preparation method thereof, and belongs to the technical field of electrochemical catalysis;The application is with acetylacetone palladium as precursor, ascorbic acid and carbon monoxide as reducing agent, oleylamine as solvent, heating reaction in high temperature reaction kettle;After reaction is completed, the obtained mixture is washed and dried, and finally the ultra-thin two-dimensional Pd nanosheet rich in grain boundary is prepared;The application not only can greatly increase basal plane active site, but also helps to optimize the electronic structure of catalyst, effectively improves catalytic performance and mass activity, and the synthesized two-dimensional Pd nanosheet rich in grain boundary can be used for fuel cell, metal air battery and efficient electrocatalyst in electrochemical oxygen reduction process.

The application discloses a Pt-CuGaO2 / C composite catalyst for an anode of a direct methanol fuel cell and a preparation method thereof; the catalyst takes a copper gallium oxide with a structure of ABO2 as a carrier of nano platinum, and the loading of the nano platinum is 5-15 wt.%; during the preparation, the copper gallium oxide carrier is synthesized by a hydrothermal method, the nano platinum is reduced by a polyol heating method, and the carbon powder is loaded by a microwave intermittent reaction method, so that the Pt-CuGaO2 / C composite direct methanol fuel cell anode catalyst with high efficiency and stability is obtained; the 5 wt.% catalyst obtains a 653.4 mA / mg Pt ‑1 mass activity, 2.53 mA / cm 2 specific activity of 25.83 m 2 A / g of electrochemical active area, and a ratio (I f / I b ) of a forward peak current density to a reverse peak current density of an index of carbon monoxide poisoning resistance is 1.50; all the catalytic activity indexes are better than those of a commercial Pt / C catalyst, and the Pt-CuGaO2 / C composite direct methanol fuel cell anode catalyst has a potential application prospect.

The application belongs to the technical field of hydrogen production by hydrolysis, and particularly relates to a method for preparing a tungsten oxide supported platinum catalyst by photoreduction and electrochemical seawater hydrogen evolution application thereof. The tungsten oxide supported platinum catalyst (Pt / WO3) prepared by using the in-situ photoreduction strategy, wherein the WO3 carrier can not only promote water dissociation, but also can regulate the microenvironment around the Pt nanoparticles by enriching hydrogen ions, thereby reducing the hydrogen evolution reaction energy barrier and improving the catalyst performance. In addition, due to the protection of the WO3 carrier, the Pt / WO3 catalyst can effectively avoid the corrosion of chloride ions in seawater, thereby improving the stability of the catalyst. Therefore, when the Pt / WO3 is applied to electrolytic seawater hydrogen evolution, the overpotential thereof is only 298 mV at 10 mA·cm ‑2 , the mass activity is 7 times that of the commercial Pt / C, and has a long-term stability of up to 140 h, which shows excellent electrolytic seawater hydrogen evolution activity and stability.

The invention provides a gradient phosphating Pt-based catalyst as well as a preparation method and application thereof, and solves the technical problems of low activity, poor stability and non-uniform phosphorus distribution of the existing Pt-based catalyst. The catalyst is formed by compounding an ordered alloy core and a gradient phosphating shell layer, the phosphorus content of the gradient phosphating shell layer is gradually reduced from the surface to a core area, and atomic-scale ordered arrangement and Pt / P element uniform distribution are achieved. The catalyst combines high stability of an L10 ordered structure and optimization of a gradient phosphorization shell layer on adsorption of a reaction intermediate, so that the catalyst shows excellent oxygen reduction reaction activity and durability in a proton exchange membrane fuel cell, and the oxygen reduction mass activity in 0.1 M HClO4 reaches 0.693 mA / mu gPt and is improved by 7.8 times compared with commercial Pt / C; after an accelerated durability test, the half-wave potential is only attenuated by 9mV, the mass activity attenuation rate is less than 6%, and the material is suitable for a high-performance fuel cell cathode material.

The application discloses a catalyst, a preparation method thereof and a fuel cell, and the catalyst comprises an inner core and a shell coated on the surface of the inner core, the inner core is a composite of a PtM alloy and C, and the shell is a nitrogen-doped carbon layer, and M single atoms are distributed in the nitrogen-doped carbon layer; wherein, M is a non-noble metal. The catalyst has stable structure, rich active sites and excellent ORR catalytic activity, and the mass activity of the catalyst is superior to that of unmodified commercial platinum carbon, and the catalyst has excellent cycle stability, and the mass activity of the catalyst after being cycled at a low potential for a period of time is higher than the initial mass activity; in addition, when the catalyst is used in the fuel cell, the power density and stability of the fuel cell can be improved.