Design,Preparation And Application Of Bimetallic Nanoparticles Catalysts

Catalytic technology plays a vital role in modern chemistry,above 90%chemical processes involve utilization of catalysts.Metal nanoparticles have a wide range of applications in catalytic field owing to its excellent catalytic activity and selectivity.However,due to the scarcity of noble metal elements,design efficient catalyst to improve the utilization efficiency of noble metals has become one of the research focuses in the eatalytic field.Bimetallic nanoparticles has become a new platform for design of novel efficient catalysts owing to its unique catalytic performance compared with corresponding monometallic nanoparticles due to the "synergistic effects".The research concentrates on design and preparation of bimetallic nanoparticles,and explore the application of bimetallic nanoparticles in the hydrodeoxygenation reaction of biomass and organic synthesis reaction units.As a starting point,application of bimetallic nanoparticles as catalysts in hydrodeoxygenation of biomass was explored.Hydrogenolysis of ?-O-4 linkages with high efficiency and selectivity could be achieved uder a mild reaction condition while alloying Ni with Pd to form a bimetallic nanocatalyst.Atmospheric hydrogen or NaBH4 could be used as the hydrogen source,amount of 1-phenylethanol and cyclohexanol in hydrogenolysis products of the model compounds could be adjusted by tuning the amount of NaBH4 while using NaBH4 as the hydrogen source.Hydrogenolysis products of organosolv lignin under the optimized reaction conditions were mainly consist of three small molecular fragments,the reaction condition is mild and selectivity of the products is excellent.There are a plethora of alcohol moieties(CaH-OH)in natural lignin,which could act as the hydrogen source for the C-O linkage cleavage reaction.A MIL-100(Fe)supported Pd-Ni bimetallic nanoparticles catalyst has been fabricated,the catalyst exhibited superior catalytic performance toward self-hydrogen transfer hydrogenolysis reaction of lignin model compounds and organosolv lignin.Depolymerization products of organosolv lignin under the optimized reaction condition were a series of phenols and aryl ketones.No extra hydrogen donor was needed in this reaction,which offer a more economical choice for large-scale operation of lignin depolymerization.Subsequently,bimetallic nanoparticles were also applied in the hydrodeoxygenation of vanillin.Vanillin is a common component of pyrolysis oil derived from lignin fraction,research on hydrodeoxygenation of vanillin is of significance for application of biofules.Pd1Ni4 bimetallic nanoparticles immoblised on active carbon was used as the catalyst,vanillin could be selectively transformed into 2-methoxy-4-methylphenol under a mild reaction condition.Compared with monometallic Pd catalyst,Pd-Ni bimetallic nanoparticles show a better catalytic efficiency in hydrogenolysis of the intermediate(vanillin alcohol).Furthermore,we also explored the application of bimetallic nanoparticles in the organic synthesis reaction units.An efficient recyclable SiO2 supported Pd-Cu bimetallic nano-catalyst has been prepared,selective hydrosilylation of internal and terminal alkynes could be achieved in the absence of ligand at room temperature.Alloying Cu with Pd obviously improve the catalytic activity and utilization efficiency of Pd.Besides,electronic synergy between Pd and Cu significantly speed up the hydrosilation process and improve the selectivity of the E isomers product.Activation of "inert" C-O bonds in ethers could be realized in the presence of the Pd-Ni@UiO-66 catalyst,Methylation and arylation of ethers could be achieved under a mild reaction condition,which highlights the great potential value of ethers as powerful alternatives for aryl halides in the organic synthesis.Finally,Pd-Ni@MIL-100(Fe)catalyst was farbicated and used in the switchable transformation between tetrahydroquinoline and quinolone.Dehydrogenation and hydrogenation reactions could be achieved in the presence of the same catalyst and solvent.Tetrahydroquinoline was transformed into quinoline at 130? under argon atmosphere(hydrogen release);quinoline was hydrogenated into tetrahydroquinoline in the presence of 0.4 MPa hydrogen at 60 ?(hydrogen storage).Dehydrogenation of tetrahydroquinoline was proceeded in the absence of external hydrogen scavenger using water as a sustainable solvent,which endows Pd-Ni@MIL-100(Fe)catalyst great potential value in liquid organic hydrogen storage compounds and organic systhesis.Six catalytic systems based on bimetallic nanoparticles were established for hydrodeoxygenation of biomass and organic synthesis reaction units.Alloying with another metal significantly improve the catalytic efficiency and selectivity of bimetallic nanoparticles in the hydrodeoxygenation reaction,which is of significance for further application of biomass.Besides,bimetallic nanoparticles also show excellent catalytic performance in organic synthesis reaction due to "synergetic effects" between two metal compoents,which highlights the great potential value of bimetallic nanoparticles in the catalytic field.