56 results about "Pd nanoparticles" patented technology

The invention provides a Cu2O-based heterogeneous composite material as well as a preparation method and application thereof. The preparation method comprises the following steps: coating the surface of a Cu2O hollow sphere substrate with a carbon layer, and depositing layered double hydroxides (LDHs) and metal palladium (Pd) nanoparticles on the carbon layer. According to the material, through a Cu2O-carbon layer-LDHs-Pd multistage heterostructure design, space optimization of light absorption, charge transfer and catalytic sites is realized; cu2O-carbon layer-LDHs interface coupling promotes directed migration of photo-induced electron-hole pairs, and the surface plasmon resonance effect of Pd nanoparticles enhances the charge separation efficiency; the LDHs optimizes a charge transfer path through surface oxygen vacancy or metal valence cycle, so that synergistic oxidation of non-free radicals and free radicals is realized, the organic matter degradation efficiency is remarkably improved, the oxidation path is widened, and the performance bottleneck of a single material is broken through.

The invention discloses a catalyst for catalyzing ethane to prepare ethylene or an oxygen-containing compound as well as a preparation method and application of the catalyst, and belongs to the field of catalysts. On the basis of ERB-1 and MCM-22, a large number of hydroxyl structures are formed through post-treatment of nitric acid or ammonium nitrate; a titanium source and molecular sieve silicon hydroxyl are subjected to a dehydrohalogenation reaction in a titanium halide gas form to form a Ti-O-Si bond, so that titanium successfully enters a molecular sieve framework and is uniformly distributed. Au or Pd is anchored by a framework Ti, Au or Pd is loaded by using a deposition-precipitation method, and the introduced Ti species can provide a better environment for further dispersing Au or Pd by changing isoelectric points on the surface of a molecular sieve carrier, so that the size of Au or Pd nanoparticles is controlled; secondly, due to the high specific surface area of the MWW molecular sieve, the gold precursor can be effectively dispersed, and agglomeration is inhibited; compared with an MWW molecular sieve of pure Si, Au or Pd nanoparticles can be dispersed and anchored by introducing a framework Ti, so that an Au and Pd-based catalyst which is about 2nm in size and good in dispersion is prepared.

This invention discloses a method for modifying the support medium of a Pd catalyst and its application. The preparation method of the Pd catalyst includes reacting zirconium salt, organic ligands, and acid to obtain a support UiO-66-X; then loading Pd onto the support UiO-66-X and reducing it to obtain the catalyst Pd@UiO-66-X; the organic ligands include 2-nitroterephthalic acid, 2-methoxyterephthalic acid, 2-aminoterephthalic acid, and terephthalic acid, and X is selected from NO2, OMe, NH2, and H. This invention changes the surface electron cloud density of the supported Pd nanoparticles by changing the ligands (-NO2, -H, -OMe, -NH2) of the support UiO-66, resulting in different abilities to activate hydrogen, thereby regulating the dehydrogenation and hydrogenation reactions in the racemicization process of Pd catalysis. The synergistic effect of different ligands with Pd changes the racemicization catalytic activity.

The invention discloses a Pd-SnO2-SiO2 self-supporting flexible nanofiber membrane gas sensor for hydrogen detection and a preparation method of the Pd-SnO2-SiO2 self-supporting flexible nanofiber membrane gas sensor, and aims to solve the problems that an existing flexible gas sensor depends on an organic substrate and is poor in high temperature resistance and insufficient in room temperature performance. According to the sensor, an electrostatic spinning technology is adopted for preparing a double-phase nanofiber membrane with crystalline phase SnO2 as a framework and amorphous phase SiO2 as a filling agent, and self-supporting can be achieved without a flexible substrate; pd nanoparticles are deposited on the fiber membrane through magnetron sputtering, and an Ag interdigital electrode is printed. Wherein the crystal-amorphous double-phase structure not only endows the material with excellent flexibility and high air permeability, but also provides a rich gas reaction interface; due to the full-inorganic characteristic, the high-temperature-resistant performance is achieved. The sensor shows high sensitivity, high selectivity and good flexible stability to hydrogen at room temperature under the environment of 37 DEG C and 80% humidity, is suitable for detecting hydrogen exhaled by a human body through wearable equipment such as a mask, and provides a new scheme for the metal oxide flexible gas sensor.

The invention provides a catalyst as well as a preparation method and application thereof and a preparation method of tetrahydrofurfuryl alcohol, the catalyst takes mesoporous silica as a carrier, the surface of the carrier is modified with polyethylene glycol and an alkyl chain to form an amphiphilic surface, and Pd nanoparticles are loaded in mesopores. The surface of the mesoporous silica supported palladium catalyst is modified with polyethylene glycol and alkyl chains through covalent bonds to form an amphiphilic interface, hydrophilic polyethylene glycol chains enrich furfuryl alcohol molecules through hydrogen bonds, and hydrophobic alkyl chains capture hydrogen microbubbles, so that the gas-liquid interfacial tension can be effectively reduced, large bubbles can be broken, and nano bubbles can stably exist; and the preparation of tetrahydrofurfuryl alcohol realizes efficient reaction under obviously reduced pressure.

The invention discloses a preparation method of a difunctional Pd catalyst co-modified by a hydrophobic anionic ionic liquid and NOH and application of the difunctional Pd catalyst in direct synthesis of H2O2. According to the catalyst, a porous material is used as a matrix, a NOH layer which provides rich hydroxyl groups and amino groups and has adhesion is used as a first modified layer, anion ionic liquid (IL-Cl) is used as a second modified layer, and chloropalladate radicals PdCl4 < 2-> are chemically grafted on the first modified layer and the second modified layer and are reduced into Pd nano particles in situ, so that the Pd nano particles are obtained. And finally, carrying out ion exchange with anion Cl <-> on the ionic liquid to introduce hydrophobic anions on the catalyst to obtain the difunctional Pd catalyst. The difunctional Pd catalyst provided by the invention has high catalytic activity, high H2O2 selectivity and high yield, and also has good stability.

The invention relates to the technical field of catalysts, in particular to a palladium-based catalyst derived from MOFs as well as a preparation method and application of the palladium-based catalyst. The preparation method comprises the following steps: firstly preparing an MOF material, then preparing a palladium-based MOF precursor, mixing the palladium-based MOF precursor with a nitrogen-containing precursor, heating and roasting in an inert atmosphere, and cooling to room temperature. An external nitrogen-containing precursor is introduced in the high-temperature pyrolysis process and is jointly roasted with a palladium-based MOF precursor, the nitrogen doping amount in the carbon carrier is remarkably increased, and high dispersion and electronic structure optimization of Pd particles are achieved by enhancing the anchoring effect and electronic regulation and control of nitrogen species on the Pd nanoparticles; therefore, high activity, high selectivity and high stability are simultaneously obtained in the selective hydrogenation reaction of 2-methyl-3-butyne-2-alcohol.

The application is suitable for the technical field of nanometer material synthesis and application, and provides a preparation method of crystalline PdCN@amorphous PdP core-shell nanoparticles, which comprises the following steps: polyvinylpyrrolidone, L-ascorbic acid and potassium bromide are added into deionized water to form a mixed solution, after preheating of an oil bath, sodium chloropalladate solution is injected, and then transferred to the oil bath for reaction, and after centrifugation and cleaning, cubic Pd nanoparticles are obtained; the cubic Pd nanoparticles are dissolved in dimethyl sulfoxide solution, transferred to a reaction kettle for reaction, and after centrifugation and cleaning, cubic PdCN nanoparticles are obtained; the cubic PdCN nanoparticles are mixed with oleylamine solution, and after adding trioctylphosphine solution and heating, centrifugation and cleaning, the crystalline PdCN@amorphous PdP core-shell nanoparticles are successfully obtained. The reagents used in the application can be purchased on the market and do not need further treatment, the preparation method is simple, and the required equipment is all basic laboratory equipment, without expensive equipment and instruments.

The invention provides a nano array for exposing a SnO2 high-activity crystal face, a preparation method of the nano array and application of the nano array in hydrogen sensing. The preparation method of the Pd-SnO2 nanowire array comprises the following steps: (1) synthesizing a SnO2 nano array on the surface of a substrate; and (2) loading the Pd nano particles on the SnO2 nano array, so as to obtain the Pd-SnO2 nanowire array. The palladium nanoparticle-loaded SnO2 nanowire array can rapidly and sensitively detect hydrogen under a low-temperature condition, has excellent sensitivity, shows excellent selectivity and reliable stability, has a detection lower limit reaching a ppm level, and is high in response speed and good in reproducibility. When the palladium nanoparticle loaded SnO2 nanowire array is used for preparing a hydrogen sensing device, the energy consumption is reduced, and the hydrogen sensing device is safer and more environment-friendly.

The application provides a Pd-Cu bimetallic supported In2O3-TiO2 catalyst and a preparation method and application thereof, and belongs to the technical field of CO2 hydrogenation to prepare methanol. The catalyst comprises a composite carrier and Pd nanoparticles and Cu nanoparticles supported on the surface of the composite carrier. Pd and Cu are combined to form bimetallic sites in the application, the advantages of the bimetallic sites can be fully exerted, and the reaction activity of CO2 hydrogenation to prepare methanol can be significantly improved through the electronic effect and geometric effect between the metals. The Pd-Cu / In2O3-TiO2 catalyst provided by the application has the advantages of high conversion rate and high catalytic activity in the reaction of carbon dioxide hydrogenation to prepare methanol; wherein, in the process of carbon dioxide hydrogenation, the Pd-Cu / In2O3-TiO2 catalyst can obtain a one-way CO2 conversion rate of 23.5% and a methanol yield of 15.83% at 250 DEG C.

The invention discloses a preparation method and application of a nitrogen-doped carbon nanotube modified Beta zeolite loaded PdNi bimetallic catalyst of dodecahydro-N-ethyl carbazole, and aims to solve the problems of high dehydrogenation temperature, low rate and the like in the application of 12H-NEC catalytic dehydrogenation. The preparation method comprises the following steps: 1, adding Beta zeolite into a nickel salt aqueous solution, dipping to obtain a Ni / Beta catalyst, mixing melamine and the Ni / Beta catalyst, putting the mixture into a tubular furnace, and carrying out a carbon thermal reduction reaction at the temperature of 500-900 DEG C in an N2 atmosphere; and 2, adding the Ni / Beta-NCNT into a solution of a palladium precursor, and carrying out an electric replacement reduction reaction. The introduction of the NCNT improves the electron transport capacity, defect sites formed on the surface of the CNT after N doping promote dispersion of Pd nanoparticles, and the synergistic effect of the two effectively improves the catalytic performance of the Pd nanoparticles in the dehydrogenation reaction of dodecahydro-N-ethyl carbazole.

The invention provides an alkaline modified UiO-66 supported Pd nano-catalyst as well as a preparation method and application thereof, and relates to the technical field of catalysts. According to the catalyst, UiO-66 serves as a precursor, isonicotinic acid is used for substitution modification through a solvent-assisted ligand exchange strategy, then Pd nanoparticles are loaded through a co-reduction method to form the corresponding composite catalyst Pd / UiO-66-PA, and the catalyst is a regular octahedral porous composite material; the invention further provides application of the alkaline modified UiO-66 loaded Pd nano-catalyst in efficient hydrogen generation through formic acid decomposition. The catalyst has the advantages of being porous, multiple in active sites and the like, has multiple pore structures in the synthesis process, can effectively load Pd nano-particles in the catalyst, and maintains good overall morphology before and after loading. The catalyst can be used as a catalyst for decomposing formic acid to generate hydrogen, and has excellent catalytic performance at 60 DEG C.

The present application relates to the field of gas detection, in particular to a titanium carbide composite material, a preparation method thereof and a hydrogen detection application. The titanium carbide composite material comprises Ti3C2T x substrate and Pd nanoparticles loaded on the Ti3C2T x substrate. The Ti3C2T x substrate is a multilayer structure, and at least part of the Pd nanoparticles are loaded between the layers of the Ti3C2T x substrate multilayer structure. The hydrogen sensor using the titanium carbide composite material of the present application can detect hydrogen with high sensitivity and high selectivity in a room temperature environment.

The invention discloses an amino-functionalized rodlike silicon dioxide loaded monometal Pd nano-catalyst and application thereof, after rodlike silicon dioxide is subjected to surface modification by 3-aminopropyltrimethoxysilane, a Pd precursor solution and amino-functionalized rodlike silicon dioxide are mixed, and loaded Pd nano-particles are subjected to reduction treatment by sodium borohydride. Compared with a traditional spherical silicon dioxide carrier, the unique morphology of the rod-like silicon dioxide carrier adopted by the catalyst provides a high specific surface area and a short mass transfer channel, the anchoring capacity of Pd nanoparticles is improved through amino functionalization, sintering is inhibited, and efficient and uniform loading and small size control of single metal Pd are achieved. The catalyst is used for room-temperature formic acid decomposition hydrogen production reaction, and shows 100% formic acid conversion rate, 100% hydrogen selectivity, good cycling stability and high initial TOF (Time of Flight) value.

The invention relates to a palladium molecular sieve catalyst and a preparation method and application thereof, the preparation method comprises the following steps: (1) mixing palladium salt with an organic solvent, and adding a high-silicon molecular sieve carrier to obtain a catalyst precursor; and (2) carrying out non-equilibrium thermal shock treatment on the catalyst precursor, and cooling to obtain the palladium molecular sieve catalyst. A non-equilibrium thermal shock method is adopted, second-level transient heating is used for promoting in-situ decomposition and anchoring of a Pd precursor on the surface of the molecular sieve, Pd nano-particles which are uniform in particle size and uniform in dispersion are obtained, and the problem that precious metal is sintered and gathered in the steady-state roasting process is effectively solved; the catalyst shows excellent low-temperature activity and long-term stability in methane catalytic combustion reaction, effectively solves the problem of catalyst deactivation caused by high temperature and high water vapor in industrial waste gas treatment, and has important application potential in the field of environmental protection such as gas engine waste gas and coal mine gas treatment.

The invention discloses application of a composite hollow nanotube array which is coated with an MOF hydrophobic layer and has a core-sheath structure in gas-sensitive moisture resistance. The preparation method of the composite hollow nanotube array comprises the following steps: (1) synthesizing a ZnO nanowire on a substrate in situ as an array template; growing on the surface of the ZnO nanowire through a hydrothermal method to obtain an etching layer containing Sn, and sintering the etching layer containing Sn to obtain a SnO2 hollow nanotube array; and (2) loading Pd nano-particles and coating an MOF hydrophobic layer on the surfaces of nano-tubes of the SnO2 hollow nano-tube array in sequence to obtain the composite hollow nano-tube array. The composite hollow nanotube array has excellent sensitivity and selectivity, the lower limit of detection can reach the ppm level, the response speed is high, and the anti-humidity effect is good.

The present invention discloses an optical hydrogen sensing material, a preparation method thereof, and a method for optically detecting hydrogen concentration. The optical hydrogen sensing material comprises a non-continuous thin film structure composed of densely arranged Pd nanoparticles. The preparation method is based on cluster beam deposition technology, in which Pd nanoparticles are deposited at a low deposition rate on the surface of a highly transparent quartz plate to form a disordered nanoparticle film with a certain visible light absorbance. Due to the interaction between the Pd nanoparticles, the particles are mutually coupled through the excited surface plasmon resonance, thereby presenting a significant plasmon resonance peak in the optical absorption spectrum. When the Pd nanoparticles reversibly adsorb hydrogen, the optical absorption spectrum will undergo significant quantitative changes depending on the external hydrogen concentration, thereby realizing the hydrogen sensing function. The key point in the preparation of the hydrogen gas-sensitive film is to deposit the Pd nanoparticles at an appropriate deposition rate to form a specific nanoparticle assembly structure and obtain a more stable sensor baseline.

This application relates to the field of catalyst technology, disclosing an electron-rich Pd nanocatalyst, its preparation method, and its application. The electron-rich Pd nanocatalyst comprises a sheet-like Mg(OH)₂ support and Pd nanoparticles uniformly loaded on the sheet-like Mg(OH)₂ support; wherein the thickness of the Mg(OH)₂ sheet is less than 2 nm; and the average particle size of the Pd nanoparticles is less than 4 nm. The preparation method includes dispersing the Mg(OH)₂ support in water, sequentially adding a palladium source and urea, refluxing at 55-65°C to obtain a precursor solution; adding a reducing agent to the precursor solution to carry out the reaction, collecting the solid deposit, washing, and drying to obtain the final product. This application, by regulating the electronic structure of the Pd nanoparticles, significantly increases the electron density on their surface, increasing the repulsion of reaction products, weakening the adsorption of reaction products on the catalyst surface, avoiding poisoning of the catalyst active sites, and improving the reactivity and selectivity of the Pd nanocatalyst for the hydrogenation of nitrile compounds at low temperatures.

The application provides a catalyst and a preparation method, application and a preparation method of tetrahydrofurfuryl alcohol, the catalyst uses mesoporous silica as a carrier, the surface of the carrier is modified with polyethylene glycol and an alkyl chain to form an amphiphilic surface, and Pd nanoparticles are loaded in the mesopores. The mesoporous silica supported palladium catalyst has an amphiphilic interface formed by polyethylene glycol and an alkyl chain modified on the surface through a covalent bond, the hydrophilic polyethylene glycol chain enriches furfuryl alcohol molecules through hydrogen bonds, and the hydrophobic alkyl chain captures hydrogen microbubbles, which can effectively reduce the gas-liquid interfacial tension, is helpful to the breaking of large bubbles and the stable existence of nanobubbles, and makes the preparation of tetrahydrofurfuryl alcohol realize efficient reaction under significantly reduced pressure.

The invention discloses a CeO2 loaded noble metal nanoparticle and a low-temperature dispersion method. The method comprises the following steps: (1) mixing cerium oxide and metal platinum salt or metal palladium salt, and grinding to obtain solid powder; (2) roasting the solid powder obtained in the step (1) in an oxygen atmosphere; (3) roasting the solid powder obtained in the step (2) in a hydrogen atmosphere to obtain Pt or Pd nanoparticles loaded on the CeO2 carrier; and (4) carrying out low-temperature roasting treatment on the Pt or Pd nanoparticles loaded on the CeO2 carrier obtained in the step (3) in an NO atmosphere to obtain further dispersed Pt / CeO2 or Pd / CeO2. According to the method, the supported metal nanoparticles can be further dispersed at the low temperature of 200-400 DEG C, meanwhile, elements such as Cl do not need to be additionally introduced, the treatment method is simple, and industrial application prospects are achieved.

The invention relates to the technical field of gas sensors, and discloses a high-selectivity hydrogen sensor and a preparation method thereof.The sensor comprises an electrode plate and a gas sensitive layer attached to the surface of the electrode plate, and the gas sensitive layer is made of a Pd / WO3 composite material; the composite material is prepared from nano WO3 powder, potassium chloropalladite, Pluronic F-127 and L-ascorbic acid at room temperature through a chemical reduction method. According to the invention, ascorbic acid is adopted as a mild reducing agent and has a synergistic effect with a Pluronic F-127 dispersing agent, so that highly dispersed loading of Pd nanoparticles on the surface of WO3 is realized, and electron sensitization and chemical sensitization effects are enhanced. The obtained hydrogen sensor can work at room temperature, shows extremely high sensitivity, excellent selectivity and good stability to hydrogen, and is simple in preparation process, low in cost, small in energy consumption and suitable for large-scale popularization and application.

The invention discloses a porous carbon supported noble metal catalyst and a preparation method thereof, the catalyst comprises an N-P double-doped porous carbon carrier and a Pt / Pd nanoparticle and Fe / W monatomic composite active site, and the distance between the N-P double-doped porous carbon carrier and the Pt / Pd nanoparticle and Fe / W monatomic composite active site is 1-3 nm. Through N-P doping mediation electron coupling, metal electron state optimization and active site compounding, functional division of reactant activation, intermediate stabilization and toxic species removal is realized, and a dual anti-poisoning barrier is formed. The preparation process of the catalyst is mature, the dosage of noble metal is reduced by 30-50%, the catalytic efficiency is improved by 40-60%, the retention rate of CO / sulfur poisoning resistance activity is 95-98%, the retention rate of activity after 500 cycles is 90-95%, and the catalyst is suitable for various industrial catalysis scenes.

The invention discloses a preparation method and application of an Mxene-derived carbon-loaded iron-palladium heterojunction ORR / OER bifunctional electrocatalyst, and the specific process is as follows: mixing a mixed solution containing Fe < 3 + > and Ni < 2 + > with a Ti3C2Tx colloidal solution, then adding an alkaline solution, and carrying out a hydrothermal reaction in a non-oxygen atmosphere to obtain a NiFe LDH-coated IL / CDC colloidal solution; the method comprises the following steps: adding a Pd < 2 + >-containing solution into a Ti3C2Tx colloidal solution, and carrying out hydrothermal preparation to prepare IL / Ti3C2Tx derived carbon coated Pd nanoparticles; and mixing with a colloidal solution, and carrying out an ultrasonic reaction to prepare the ORR / OER bifunctional electrocatalyst. The electrocatalyst prepared by the invention has the characteristics of large pore specific surface area, high active site density, low resistance, low overpotential and the like, and shows the advantages of high catalytic efficiency, long-term stability and the like in the charge-discharge reaction of the zinc-air battery under low and high current density.

The application discloses a palladium-loaded vanadium oxide doped nitrogen-carbon material and a preparation method and application thereof, and the preparation method is as follows: S1, zinc salt and vanadium salt are dissolved in a composite solvent according to a mass ratio of 95:3-7, then 1H-1,2,3-triazole is added to form a suspension A, the obtained suspension A is continuously stirred and reacted, then is centrifuged, washed and dried to obtain a Zn / V-MET-6 product; S2, the Zn / V-MET-6 is calcined in a tube furnace at 850 DEG C-1000 DEG C for 1h-4h, and then is cooled to room temperature to obtain vanadium oxide doped nitrogen-carbon; S3, the vanadium oxide doped nitrogen-carbon is uniformly stirred and mixed with water and sodium tetrachloropalladate, then a sodium borohydride reducing agent is added, after a reduction reaction, a suspension B is obtained; the obtained suspension B is centrifuged, washed and dried to obtain the palladium-loaded vanadium oxide doped nitrogen-carbon material; the catalyst loads Pd nanoparticles in a carrier, and after reduction, a porous composite material is obtained, the catalyst has good stability and excellent performance in catalyzing decomposition of formic acid.

The invention belongs to the technical field of electrochemical catalysis, and particularly relates to a composite electrocatalyst, a preparation method thereof and application of the composite electrocatalyst in preparation of organic acid salt by electrocatalytic oxidation of alcohol compounds. The preparation method of the composite electrocatalyst comprises the following steps: taking soluble palladium salt, a reducing agent and a first surfactant as raw materials, taking foam metal as a substrate material, loading Pd nanoparticles on the foam metal in a weak acid environment by adopting a solvothermal method, and recording as Pd / foam metal; pd / foam metal is used as a working electrode substrate, and Ni nanoparticles are deposited on the surface of the Pd / foam metal in situ by adopting an electro-deposition method under the action of supporting electrolyte, soluble nickel salt and a second surfactant. The composite electrocatalyst can be used for electrocatalytically oxidizing various alcohol compounds (such as methanol, ethanol, ethylene glycol, 1, 2-propylene glycol, 1, 3-propylene glycol, glycerol, 1, 3-butanediol, 1, 4-butanediol and the like) into high-value-added chemical organic acid salts, so that the value of the alcohol compounds is increased.

The invention belongs to the technical field of gas sensing, and relates to a Pd / SiC-C core-shell nanowire, a high-temperature hydrogen sensor as well as a preparation method and application of the Pd / SiC-C core-shell nanowire. According to the Pd / SiC-C core-shell nanowire, a cubic silicon carbide nanowire serves as an inner core, an amorphous mesoporous carbon shell layer is formed on the inner core in an in-situ growth mode, Pd nanoparticles are coated with the amorphous mesoporous carbon shell layer, the Pd nanoparticles are evenly anchored to the surface of the cubic silicon carbide nanowire, and a stable Pd / SiC-C core-shell structure is formed. The structure effectively inhibits agglomeration and falling of Pd nano-particles in a high-temperature environment, and the dispersity and thermal stability of Pd are remarkably improved. When the material is applied to a hydrogen sensor, high sensitivity, quick response / recovery characteristic and excellent long-term stability are shown, a reliable solution is provided for hydrogen detection under high-temperature harsh working conditions, and the material has important engineering application value in the fields of aerospace, hydrogen energy storage and transportation and the like.

The invention discloses a copper-zinc-zirconium-molecular sieve composite catalyst based on a gradient interface structure and application of the copper-zinc-zirconium-molecular sieve composite catalyst in synthesis of methanol from green hydrogen, belongs to the technical field of catalytic materials and green energy, and particularly relates to design of a composite catalyst for preparation of methanol from carbon dioxide through hydrogenation. Particularly aiming at an efficient conversion scene of green hydrogen (renewable energy source water electrolysis hydrogen production) and carbon dioxide capture, hydrogen activation and reaction path regulation are optimized through a gradient interface structure. According to the catalyst, a Cu-Zn-Zr solid solution is used as a core layer, an SAPO-34 molecular sieve is used as a shell layer, and Pd nanoparticles and an La2O3 auxiliary are loaded at an interface. Through the gradient interface design that a solvothermal synthesis core layer, a sol-gel coating shell layer and Pd are introduced through a chemical deposition method, the selectivity of methanol preparation through CO2 hydrogenation and the hydrogen utilization rate are remarkably improved. The device is suitable for a renewable energy electrolysis hydrogen production system, and adapts to the European Union carbon emission standard (1t, 56 kg CO2 / kg methanol).

The invention relates to the technical field of environmental protection and new energy, and particularly discloses a Pd-loaded photo-thermal catalyst and a preparation method and application thereof, and the Pd-loaded photo-thermal catalyst comprises a rare earth hexaboride carrier and Pd nanoparticles; the preparation method of the Pd-loaded photo-thermal catalyst comprises the following steps: weighing anhydrous rare earth chloride and magnesium boride powder, grinding, uniformly mixing, calcining in vacuum, cooling to room temperature, soaking in a dilute sulfuric acid solution, stirring, centrifuging, washing and drying to obtain a rare earth hexaboride carrier; the preparation method comprises the following steps: adding a PdCl2 solution and a rare earth hexaboride carrier into water, stirring until the solution is completely evaporated to dryness, calcining, and reducing by using H2-Ar mixed gas to prepare the Pd-loaded photo-thermal catalyst. According to the photo-thermal catalyst, Pd nanoparticles are loaded on the surface of a rare earth hexaboride carrier, and the performance of catalyzing NO hydrogenation synthesis ammonia reaction by transition metal Pd is improved in a photo-thermal synergistic mode.

The invention belongs to the technical field of photocatalysis, and particularly relates to a preparation method and application of a multifunctional sulfur-zinc-cadmium photocatalyst. The method comprises the following steps: preparing a sulfur-zinc-cadmium crystal nucleus through a liquid-phase ion exchange method, promoting regrowth of the sulfur-zinc-cadmium crystal nucleus through a molten salt calcination method to obtain a sulfur-zinc-cadmium photocatalyst, and carrying out sulfur ion modification on the surface of the sulfur-zinc-cadmium photocatalyst through a coprecipitation method to obtain sulfur-zinc-cadmium with a sulfur-rich surface. And finally, selectively depositing Pd nano-particles on the high-index crystal face of the sulfur-zinc-cadmium with the sulfur-rich surface through photochemical reduction to obtain the multifunctional sulfur-zinc-cadmium photocatalyst. The catalyst can be used for a reaction system for preparing N-benzylidenebutylamine through benzylamine coupling, preparing hydrogenated benzoin through benzyl alcohol coupling, preparing 2-hydroxymethyl pyrazine through 2-formic acid pyrazine reduction and preparing benzaldehyde and other template micromolecular aromatic compounds through benzyl alcohol oxidation. The catalyst is simple in preparation method and wide in raw material source, can drive reactions such as coupling, reduction and oxidation of small molecular aromatic compounds, and has industrial application prospects.

The invention belongs to the technical field of gas sensing materials and safety monitoring, and discloses a gas leakage detection color-changing flexible film based on lead acetate dual-mode response and a preparation method and application thereof, and the method comprises the following steps: coating a molecular sieve layer: mixing ZSM-5 zeolite powder with polyvinyl alcohol, and blade-coating a PET substrate; catalytic layer loading: ball-milling and mixing lead acetate, Pd nanoparticles and mesoporous SiO2, and coating the molecular sieve layer with the mixture to obtain a Pd-lead acetate catalytic layer; performing reaction layer and packaging: performing pure lead acetate slurry coating to obtain a reaction layer, and performing vapor deposition on a PI layer to obtain a packaging layer; gum treatment: spraying high-temperature-resistant silica gel, and curing to form a self-adhesive layer; the mass ratio of the molecular sieve layer to the Pd-lead acetate catalyst layer to the reaction layer to the encapsulation layer is (20-30): (50-60): (10-15): (5-10). The product provided by the invention has relatively good flexible adaptability and environmental robustness; and quick response and low-cost mass production can be realized.