151 results about "Pd nanoparticles" patented technology

The invention discloses a high-efficiency nano Pd catalyst used in the process of preparing oxalate through CO carbonylation. The catalyst comprises alpha-aluminum oxide serving as a carrier and 0.05 to 2 weight percent of noble metal Pd nanoparticles serving as active ingredients. The catalyst is prepared by a dipping-alkali-free liquid phase controllable reduction method. The catalyst is high in metal dispersion degree and narrow in dimensional distribution and can efficiently catalyze CO gas phase carbonylation to prepare the oxalate under the conditions of low temperature and low noble metal load, wherein the single-pass conversion ratio of the CO is 48 percent; the selectivity of the oxalate is over 99 percent; and the space time yield of the oxalate is more than 1,000 g.L<-1>.h<-1> (space velocity is 3,000 h<-1>).

The invention discloses a Pd/TiO2/C composite nano-catalyst and a preparation method thereof. The Pd/TiO2/C composite nano-catalyst consists of nano-Pd, nano-TiO2 and active carbon powder, wherein the mass ratio of the nano-Pd to the nano-TiO2 to the active carbon powder is preferably 1:2:2. The preparation method comprises the steps of preparing nano-TiO2 powder by a hydrothermal synthesis method, preparing a mixed solution of a carrier consisting of active carbon and TiO2, loading Pd nanoparticles on the carrier consisting of the active carbon and the TiO2 by a liquid phase reducing method and the like. The nano-TiO2 with high stability in acid and alkaline solution and the treated active carbon form the composite carrier, so compared with the traditional carrier only comprising the active carbon, the Pd/TiO2/C composite nano-catalyst has higher catalytic activity on ethanol and stability.

The invention provides a method for preparing core-shell structural nanometer metal particles. Spherical Pd nanoparticles are taken as a core; Pt nanodendrites are taken as a shell; and the nanometer metal particles can be taken as a low-temperature fuel cell catalyst. The preparation method comprises the following steps of: reducing precursors of Pd and Pt with ascorbic acid by taking deionized water as a solvent and taking a segmented copolymer as a protecting agent; and preparing nanoparticles according to different reducing sequences of the ascorbic acid on the Pd and Pt precursors, wherein the Pt shell has a nanometer dendritic crystal structure. A supported catalyst can be obtained by adding a carrier into nanoparticle sol obtained by reacting. The preparation method adopted by the invention has the advantages of easiness, environment friendliness, energy saving and the like. The prepared core-shell structural catalyst shows high area specific activity and unit mass Pt catalytic activity on an oxygen reduction reaction.

The invention discloses a mesoporous graphite carbon nitride/palladium composite material, preparation method and application thereof. A carrier of the composite material is mesoporous g-C3N4, and an active component is Pd nanoparticles with particle size being 10-20 nm. Capacity of the Pd nanoparticles is 1.0-10% of total mass of the composite material. The preparation method comprises the following steps: firstly calcining to obtain blocky g-C3N4, carrying out oxidization and ultrasonic treatment to obtain the mesoporous g-C3N4, and finally loading noble metal Pd so as to obtain the target composite material. The composite material has larger specific surface area, and any other sacrificial template is not needed, thus being more beneficial to loading of the Pd nanoparticles. The g-C3N4/Pd composite material which is applied as a catalyst for reduction reaction of p-nitrophenol shows high catalytic activity.

The invention belongs to the field of luminescent materials, and discloses a titanate luminescent material and a preparation method thereof. The general chemical formula of the titanate luminescent material is as follows: M1TiO3.xPr.yM2, wherein M1 is selected from at least one of Ca, Sr and Ba, M2 is selected from at least one of Ag, Au, Pt and Pd nanoparticles, x is equal to 5*10<-5>-1*10<-2>, and y is equal to 5*10<-7>-1*10<-4>. The titanate luminescent material disclosed by the invention is simple in manufacturing processes and low in equipment requirements; and compared with the luminescent property of the fluorescent powder prepared without doping metal particles, the luminescent property of the fluorescent powder prepared by doping metal particles is greatly improved.

In one embodiment, SWNTs are synthesized from an embedded catalyst in a modified porous anodic alumina (PAA) template. Pd is electrodeposited into the template to form nanowires that grow from an underlying conductive layer beneath the PAA and extend to the initiation sites of the SWNTs within each pore. Individual vertical channels of SWNTs are created, each with a vertical Pd nanowire back contact. Further Pd deposition results in annular Pd nanoparticles that form on portions of SWNTs extending onto the PAA surface. Two-terminal electrical characteristics produce linear I-V relationships, indicating ohmic contact in the devices.

The invention provides a method for preparing fatty alcohol through hydrogenation of fatty acid methyl ester in presence of a temperature control catalytic system. The method is characterized by adopting Pd metal nanoparticles stabilized by imidazolyl temperature control ionic liquid containing different length of polyoxyethylene ether chain segments as catalysts to catalyze hydrogenation of fatty acid methyl ester to prepare fatty alcohol under the conditions of 10.0g of fatty acid methyl ester, 0.4-1.2g of temperature control ionic liquid catalytic system (containing 0.2-10% of Pd metal nanoparticles by mass), hydrogen pressure of 4-8MPa, reaction temperature of 190-230 DEG C and reaction time of 2-6 hours and carrying out separation, recovery and cyclic utilization on the temperature control ionic liquid catalytic system containing the Pd metal nanoparticles. Compared with the prior art, the method has the characteristics that 1. the catalytic system can achieve high temperature homogeneous reaction and low temperature two phase separation; 2. the temperature control ionic liquid avoids agglomeration of the Pd nanoparticles; 3. after reaction, the catalytic system has good cyclic use property and belongs to the environment-friendly process route.

Belonging to the technical field of microreactors, the invention provides a capillary type efficient palladium-loaded zirconium based metal organic framework film microreactor, a dynamic in-situ preparation method and application thereof. The preparation method includes: introducing a 3-aminopropyltriethoxysilane chemical modification layer to an inner surface of a capillary quartz tube microreactor by dynamic method in advance; then under a continuum flow state, growing a UiO-66-NH2 zirconium based metal organic framework film layer of certain thickness; and finally, using impregnation-reduction method for continuous dynamic preparation of the UiO-66-NH2 zirconium based metal organic framework film palladium-loaded film microreactor. The invention establishes a simple and convenient new method for preparation of a film microreactor, the prepared palladium-loaded zirconium based metal organic framework film microreactor has the characteristics of continuous film layers and controllable thickness, uniformly distributed Pd nanoparticles and firm combination, and difficult fall. The film microreactor has excellent excellent catalytic efficiency in the reaction of catalyzing NaBH4 for reduction of nitrophenol organic matters, and can run stably for a long time.

The invention discloses a thiamphenicol molecularly imprinted electrochemical sensor and a preparation method and application thereof. A porous graphene-molybdenum disulfide nano flower-shaped compound is prepared through a hydrothermal one-step method, and the compound is dropped on the surface of an L-type glassy carbon electrode; aminated multi-walled carbon nanotubes and porous Pt-Pd nanoparticles are dispersed so that the imprinting surface area of the electrode can be increased and stability of a modification interface can be enhanced, and accordingly a three-dimensional porous imprinting substrate is obtained; thiamphenicol serves as template molecules, 1,2-diaminobenzene serves as functional monomers, and an imprinted membrane is prepared through cyclic voltammetry; ascorbic acid serves as a photoelectric chemical probe, and the electrochemical sensor for detecting thiamphenicol is built. The sensor has good thiamphenicol responsiveness, the linear range of the sensor is 1.0*10<-9>-3.5*<-6> mol L<-1>, and the detection lower limit is 5.0*10<-9> mol L<-1>. The sensor can be used for detecting thiamphenicol in meat samples and feed samples.

The invention discloses a ruthenium-palladium/carbon catalyst and a preparation method thereof. A catalyst carrier is a carbon material, and active ingredients are Ru and Pd nanoparticles, wherein the load capacity of Ru is 0.5%-8.0%, the load capacity of Pd is 0.1%-2.0%, and the dispersity of ruthenium-palladium can achieve 30%-80%. The carrier is subjected to acid-base oxidization pretreatment, so that surface oxygen-containing functional groups can be increased, the property of ruthenium-palladium on the surface of the carbon material can be improved, the dispersity of ruthenium-palladium can be improved, the active ingredients can be firmly adsorbed on the functional groups, and the catalyst can show high activity in the reaction process. The prepared catalyst is applied to DMT (dimethyltryptamine) hydrogenation to prepare DMCD (dimethyl 1,4-cyclohexanedicarboxylate). The activity of the catalyst is not reduced after the catalyst is used for 20 times in an autoclave of 5000ml, the conversion rate of DMT can achieve 99.3%-100%, and the selectivity of DMCD can achieve 95.5%-96.4%. The purity of DMCD, which is simply distilled and purified, is greater than 99.5%. The preparation method has the advantages of being mild in technological conditions, simple in equipment, free from emission of three wastes, economic in investment, low in energy consumption, and feasible for industrialization.

A mesoporous catalyst Pd (0)-Gn-PAMAM for the hydroreaction of unsaturated hydrocarbon is composed of Pd nanoparticles, mesoporous material and polyamideamine (PAMAM). Its preparing process includes such steps as Michael addition reaction in the mesoporous arteries to synthesize PAMAM, introduce Pd ions, and reducing by sodium bromohydride.

The invention discloses a phosphotungstic acid supported Pd-metal-organic framework (MOF) catalyst and a preparation method and application thereof. A Pd-PTA-MIL-100(Fe) composite material is obtained through dispersing a support, i.e., PTA-MIL-100(Fe) in an ethanol-water solution, rapidly reducing (PW12O40)<3-> into (PW12O40)<4-> by using ultraviolet irradiation in an N2 atmosphere, and adding H2PdCl4 to instantly reduce Pd<2+> by (PW12O40)<4->. High-dispersion noble-metal Pd nanoparticles are grown on the MOF by using a (PW12O40)<4-> assisted method, and this process does not need any additional reducer, surfactant and organic stabilizer and a heat treatment process. The prepared Pd nanoparticles are good in dispersity and high in utilization ratio and have a very efficient room-temperature photocatalytic degradation effect on drugs and personal nursing materials in water environments.

The invention relates to a high-dispersibility palladium catalyst and a preparation method and application thereof, and belongs to the technical field of catalysts and preparation thereof. The technical problems are solved that in the prior art, the preparation method of catalysts for decomposing formic acid to produce hydrogen is complicated and Pd active components are uneven in particle size, low in activity and poor in stability. The palladium catalyst is porous carbon surface-loaded with a hyperbranched polymer-Pd nanoparticle composite, a hyperbranched polymer is a polymer of difunctional dienamide and difunctional diamine, the particle size of the palladium catalyst is 0.8-2.0 nm, and the dispersion degree of Pd nanoparticles is greater than 80%. The invention further provides the preparation method of the palladium catalyst. The palladium catalyst has good dispersibility and stability and shows excellent catalytic performance for decomposing formic acid to produce hydrogen at room temperature, and the rate of catalyzing the decomposition of formic acid is high. The preparation method of the palladium catalyst is simple.

The invention discloses a sodium borohydride reduction adopted method for preparing a Pd/alpha-Al2O3 catalyst and belongs to the technical field of dimethyl oxalate preparation. The catalyst takes alpha-Al2O3 as a carrier and takes precious metal Pd nanoparticles as an active ingredient, wherein the content (by weight) of the active ingredient Pd in the catalyst is 0.05-1%. The dispersion degree of the active ingredient of the catalyst in the carrier can be controlled in a certain range; the metal dispersion degree of the catalyst prepared by the method is high, CO gas-phase carbonylation can be efficiently catalyzed at relatively low temperature and low precious metal load, so as to synthesize dimethyl oxalate, and the space-time yield of dimethyl oxalate reaches up to 1,150g/L/h (the space velocity is 2,400/h).

The invention discloses a preparation method of a Pd-nanoparticle-modified porous ZnO nanosheet gas-sensitive material, which comprises the following steps: mixing and grinding porous monocrystalline ZnO nanosheets and Pd nanoparticles, wherein the weight of the Pd nanoparticles accounts for 0.3-0.8% of the total weight of the porous monocrystalline ZnO nanosheets and Pd nanoparticles; and calcining at 550-650 DEG C for 1-2 hours to obtain the Pd-nanoparticle-modified porous ZnO nanosheet gas-sensitive material. The Pd-nanoparticle-modified porous ZnO nanosheet gas-sensitive material has high sensitivity: the sensitivity for 100ppm acetone gas is up to 70, the sensitivity for 500ppm acetone gas is up to 222, and the sensitivity for 10ppm acetone gas is up to 8 or so. The operating temperature is low: the optimum temperature of the ZnO nanosheet composite material modified by the Pd nanoparticles is 340 DEG C, and is greatly lowered as compared with 420 DEG C of the single ZnO nanosheets. The selectivity is high: the gas sensor is less sensitive to some common organic solvents, such as ethanol, methanol, benzene, toluene and the like, than acetone.

The invention discloses a supported palladium-ultrathin CoNi-LDH (Layered Double Hydroxide) nanosheet composite material as well as a preparation method and application thereof. The preparation methodcomprises the following steps: firstly, preparing ultrathin CoNi-LDH nanosheets by using a one-step hydro-alcohol thermal-solvent method, and supporting noble metal Pd nanoparticles by the ultrathinCoNi-LDH nanosheets as a carrier so as to obtain the supported palladium-ultrathin CoNi-LDH nanosheet composite material. The composite material can be applied to an electrocatalytic ethanol oxidationreaction, and has the advantages of high mass activity, good stability, good anti-poisoning ability and the like. The advantages can be attributed to the following aspects: (1), the ultrathin carriercan provide a larger electrochemical activity area, good electrical conductivity, and good CO poisoning resisting ability; and (2), the Ni-based LDH carrier can remove carbonaceous intermediates nearPdNPs sites, the Co element which is highly dispersed in laminates can achieve uniform and solid loading of PdNPs and is beneficial to sufficient utilization of PdNPs, and thus catalytic activity andstability can be synergistically improved.

The invention discloses a Pd/C catalyst and a preparation method thereof, the Pd/C catalyst takes carbon black as a carrier, and Pd metal nanoparticles are uniformly dispersed on the carbon black; themass percent of the Pd metal nanoparticles in the catalyst is 1%-70%, and the particle diameter is 2 nm to 8 nm. According to the Pd/C catalyst and the preparation method thereof, a liquid phase reduction method is used, ammonium hydroxide and NaOH are added to a Pd saline solution with certain concentration, a Pd complex ion solution is prepared, excessive reducing agent is added then, and the Pd complex ions are reduced on the dispersed carbon black carrier at certain reaction temperature. The Pd/C catalyst prepared with the method has excellent electrocatalytic activity in an oxygen-saturated 0.1 mol/L of HClO4 solution. The difficulties that the particle diameter of the Pd nanoparticles is large, clustering is difficult and the Pd/C catalyst is difficult to prepare in batches are solved.

The invention relates to a preparation method of a supported catalyst for circulating type catalytic reaction. The catalyst uses a ceramic membrane as a carrier. The preparation method comprises the following steps: growing TiO2 nanorods on the surface and in pore passages of a ceramic membrane by a two-step hydrothermal method, then etching the TiO2 nanorods into TiO2 nanotubes by a hydrochloricacid hydrothermal etching method, modifying through a silane coupling agent to introduce amino functional groups, and finally, loading Pd nanoparticles by a sol impregnation method to prepare the supported catalyst. The preparation method has the advantages that the surface and the pore passages of the ceramic membrane are modified through the TiO2 nanotubes, so that the surface area of the membrane catalyst can be expanded, more Pd nanoparticles are loaded on the surface and in the pore passages of the ceramic membrane, and the catalytic performance of the catalyst is improved; by virtue of the multiparous property of the ceramic membrane, the membrane catalyst can be used for forming a circulating type catalytic membrane reactor, the problem of difficult separation of the catalyst from aproduct is avoided, and the supported catalyst can be widely applied to the circulating type catalytic reaction process.

The invention discloses a zirconium-based MOF catalyst loaded with double active sites as well as a preparation method and an application of the zirconium-based MOF catalyst. The method comprises thefollowing steps: adding zirconium salt and an organic ligand into an organic solvent, taking organic acid as a regulator, and carrying out self-assembly reaction to obtain a metal organic framework; adding salicylaldehyde for aldehyde amine condensation to obtain chelating coordination sites, adding palladium salt, and performing coordination through an impregnation method; reducing the obtained MOF in hydrogen to obtain an MOF loaded with Pd nanoparticles; reacting MOF and zinc salt in an organic solvent, and obtaining the catalyst. The Pd-Zn-coated UiO-68-NH2-CH3 catalyst synthesized by thepreparation method disclosed by the invention has efficient catalytic activity in a tandem alcohol oxidation/aldehyde cyanosilylation reaction. According to the catalyst, a metal organic framework UiO-68-NH2-CH3 is constructed, Pd nanoparticles and Zn <2+> are loaded by taking the metal organic framework UiO-68-NH2-CH3 as a carrier, the loading capacity of the Pd nanoparticles is 4-8wt%, and the loading capacity of the Zn <2+> is 3-5wt%.

The invention discloses a preparation method of a PtPd/Fe3O4 (platinum-palladium/ferroferric oxide) nanocatalyst and an application thereof in HECK reaction, and belongs to the technical field of nanocatalysts. The preparation method is characterized in that a catalyst carrier is magnetic Fe3O4 nanoparticles, and the average particle size is 18nm; the active components are Pt and Pd nanoparticles, and the average particle sizes are respectively 12nm and 10nm; the average mass percentages of Pt and Pd in the catalyst are respectively about 0.39% and 0.75%; the balance is Fe3O4 nanoparticles. The preparation method comprises the following steps of oxidizing and reducing FeCl3 6H2O into the Fe3O4 nanoparticles by a hydrothermal method; cleaning, and metering volume for use; using polymers of polyvinylpyrrolidone and the like as stabilizers, and reducing a certain ratio of chloroplatinic acid and chloropalladic acid by a reducing agent, so as to prepare a Pt-Pd sol; adding the treated Fe3O4 nanoparticles into the Pt-Pd sol, stirring, filtering, and drying, so as to finally prepare the Pt-Pd magnetic nanometer-supported catalyst. The catalyst prepared by the preparation method has higher catalytic activity in the Heck reaction.

The invention provides a preparation method of a load type nano catalyst for catalyzing a Suzuki coupling reaction, and relates to a preparation method of a catalyst. According to the preparation method, the problem that particle redistribution and aggregation are prone to occurring on palladium nanoparticles formed in the existing chemical reagent reducing preparation process in a liquid phase system is solved. The preparation method comprises the following steps that at room temperature, activated carbon and a Na2PdC14 solution are mixed, centrifuged and dried for 12 h, and a sample is obtained; the sample is taken, evenly laid on a bearing boat and placed in a discharge tube, vacuumizing is performed, N2 plasma discharge gas is pumped in, high-voltage direct currents are applied at the two ends of an electrode, the gas in the discharge tube is broken through, glow discharge plasma is initiated, and then the load type nano catalyst is obtained. According to the preparation method, the glow discharge plasma is used for preparing the load type nano catalyst in a reduction mode, particle redistribution caused by liquid phase system reduction is avoided, and the prepared Pd nanoparticles are not prone to aggregating, small in size and homogeneours in dispersion. The method belongs to the field of catalyst preparation.

The invention belongs to the technical field of material preparation and environmental pollution control, and provides a preparation method of a Pd/C3N4@biomass carbon fiber composite film. The preparation method comprises the following steps: step 1, preparing a Pd/C3N4@biomass carbon fiber composite photocatalyst; and step 2, preparing the Pd/C3N4@biomass carbon fiber composite photocatalytic film by an electrostatic spinning method. With use of high adsorbability of biomass carbon fibers, C3N4 and Pd nanoparticles are uniformly loaded on the surface, the separation efficiency of photogenerated electrons and holes is improved, at the same time, the inherent high-porosity structure of an electrostatic spinning membrane is combined, the efficient catalytic degradation of target pollutantsis achieved, and the preparation method has the advantages of simple synthesis, high degradation efficiency and the like.

The invention discloses a Pd/crystallized carbon nitride heterojunction photocatalyst, a preparation method thereof and application of photocatalytic Ullmann coupling reaction. The catalyst is prepared in the manner that as a supporter, crystalline carbon nitride uniformly carries Pd nanoparticles with particle diameter of 3-7nm, wherein the loading capacity of Pd is 1%-10% based on 100% of the mass of the catalyst. The preparation method comprises the following steps: firstly, preparing g-C3N4 nanosheet through thermal polycondensation of melamine, then calcining with potassium chloride and anhydrous lithium chloride to obtain crystalline carbon nitride nanobelt, and reacting with palladium acetate and methanol in a closed system to obtain the Pd/crystallizationcarbon nitride heterojunction photocatalyst. The Pd/crystalline carbon nitride heterojunction photocatalyst disclosed by the invention is used for catalyzingUllmann C-C coupling reaction of halogenated aromatics to synthesize biphenyl compounds, and has the advantages of high catalytic activity and stability, mild reaction conditions, short reaction time and high product yield rate.

The invention discloses a ruthenium palladium/carbon catalyst of cyclohexanecarboxylic acid synthesized through benzoic acid hydrogenation. The catalyst comprises a carbon material carrier, an active component of metal element Ru nanoparticles and an auxiliary of metal element Pd nanoparticles. The loading capacity of the Ru nanoparticles is 0.5-0.8%, and the loading capacity of the Pd nanoparticles is 0.05-2.0%. The invention further discloses a preparation method of the ruthenium palladium/carbon catalyst. Firstly, the carbon material carrier is prepared, then the active component ruthenium and the auxiliary palladium are loaded, a catalyst precursor is obtained, and finally the catalyst precursor is dried and reduced. The catalyst avoids use of a large amount of palladium, has high reaction activity, selectivity and stability, can be used circularly and remarkably reduces production cost. The catalyst is used for synthesizing cyclohexanecarboxylic acid through benzoic acid catalytic hydrogenation. The raw material conversion rate is 100%, the purity of a target product can be higher than 99.5%, process conditions are moderate, equipment is simple, three wastes are not emitted, and industrialization is easily achieved.

The invention relates to a high temperature sintering resistive loading type noble metal catalyst for catalytic oxidation for carbon monoxide and a preparation method thereof. The catalyst comprises acarrier, active components and a cladding shell layer, wherein the carrier is TiO2 or CeO2 nanoparticles; the active components are noble metals Au, Pt or Pd nanoparticles; the active components areloaded on the surface of the carrier; the cladding shell layer which is SiO2 shell layer and clads the surfaces of the carrier nanoparticles and the noble nanoparticles of the active components. The method is simple; the condition is mild; the period is short; massive synthesizing can be carried out; and the environment is influenced a little.

The invntion discloses a Pd triple-effect low-temperature catalyst taking nitrogen-doped titanium dioxide as a carrier as well as a preparation method and application thereof. Pd nanoparticles are loaded on an N-TiO2 semiconductor carrier with a light absorption effect to prepare the loaded type Pd catalyst; a TiO2 semiconductor is doped with N and visible light is introduced, so that low-temperature and high-efficiency catalytic removal of CO/NO can be realized by utilizing a photo-thermal coupling effect. According to the Pd triple-effect low-temperature catalyst, non-metal-doped TiO2 is introduced, so that the obtained catalyst can be used for removing CO and NO under the visible light, and the catalyst, which takes non-toxic and green N-TiO2 as a semiconductor, is expected to be prepared into a smearing type; the preparation method of the catalyst is simple and feasible and the catalyst is easier to popularize and apply.

The invention discloses a sintering-resistant mosaic Pd@CeO2 nanotube catalyst and a preparation method thereof, and belongs to the field of catalysts. The catalyst comprises hollow tubular cerium dioxide (CeO2) and palladium (Pd) nanoparticles, and the Pd nanoparticles are inlaid at the inner side of the tubular CeO2; the load capacity of the Pd nanoparticles is 0.4-5.0 wt%, and the particle sizeis 2-3 nm; and the caliber of the CeO2 nanotube is 20-80 nm. Compared with traditional structured catalysts with Pd loaded on the surface of a CeO2 carrier, the catalyst of the invention can effectively prevent sintering due to the inlaying of the Pd nanoparticles at the inner side of the tubular structure of the CeO2 nanotube. The Pd is fixed at the physical position through the deposition of the CeO2 particle, and the Pd is further anchored by the chemical bonds between the Pd particle and the adjacent CeO2, so the Pd nanoparticles are still uniformly dispersed at a high temperature, and the catalyst has a good oxidation activity and stability to carbon monoxide.