Hydrogenation Of Biomass-derived Furfural Over Non-precious Metal Catalysts

As a carbon-neutral renewable resource that can be used to produce bioenergy and biomaterials,biomass can solve a series of social problems.Biomass can be converted into many chemicals.The development of simple and cheap catalysts has certain industrial and economic value for the utilization of biomass.Herein,using furfural（FFA）as a biomass platform compound,three supported non-precious metal nanoparticle catalysts（Ni/RHPC,Ni_xCu_y/RHPC and Ni-NiO/Fe₃O₄@SiO₂）have been used to study the catalytic hydrogenation performance of furfural.The structural characteristics of the catalyst were investigated by characterization methods,and the performance of the catalyst in the furfural hydrogenation reaction was also discussed.Analyze the connection and explain the reaction mechanism.The results are as follows:Ni nanoparticle catalyst（Ni/RHPC）supported by rice husk porous carbon（RHPC）was prepared by impregnation method and carbothermal reduction method.Characterization methods such as XRD,XPS,TEM,and N₂ physisorption showed that the particle size of Ni nanoparticles was 9 nm and were evenly distributed on the RHPC surface.In the Ni RHPC catalyst catalyzed the furfural hydrogenation reaction,the Ni/RHPC catalyst formed a Pickering emulsion coupled microbubble reaction system in the oil-water phase.This gas-liquid-solid multiphase system keeps the reaction at the interface,thereby significantly improving the reaction efficiency.Under mild reaction conditions（100°C,1 MPa）,the conversion of furfural was 100%,the selectivity of tetrahydrofurfuryl alcohol（THFA）reached more than 90%,and the carbon balance was 90%.At the same time,the Ni/RHPC catalyst can be reused four times without significantly reducing its catalytic activity.The development of Ni/RHPC catalyst is of great significance for the application of non-precious metal catalysts and inexpensive rice husk porous carbon.The rice husk porous carbon was modified by nitric acid（RHPC）as a carrier to support Ni_xCu_y nanocatalysts with different molar ratios（Ni_xCu_y/RHPC）.The surface of the modified RHPC contains many oxygen-containing functional groups that will generate acidic sites that can activate the formation of furfuryloxy intermediates,and the carboxyl groups in the functional groups will enhance the adsorption of furfuryl alcohol.These factors will increase the yield of THFA.Boehm titration,FT-IR,XRD,XPS,EDS,TEM,ICP-OES and other characterization methods showed that NiCu nanoparticles were uniformly supported on the surface of the support.Ni₂Cu₁/RHPC catalyst can efficiently convert furfural to THFA under mild reaction conditions（50°C,1 MPa,1 h,500 rpm）,the conversion was 100%,the yield was>99%,and the carbon balance was>90%.The high activity and selectivity of the Ni₂Cu₁/RHPC catalyst is not only due to the modification of the porous husk activated carbon support by nitric acid,but also due to the synergy between the NiCu bimetals.Ni₂Cu₁/RHPC catalyst has good stability and reproducibility in the cycle test,which shows a good application prospect in catalysis.Fe₃O₄@SiO₂ superparamagnetic material was synthesized by inverse microemulsion method,which was used as a carrier to prepare Ni-NiO/Fe₃O₄@SiO₂heterojunction nanocatalyst.The characterization methods of FT-IR,XRD,XPS,EDS,TEM,TG and H₂-TPR showed that Ni-NiO/Fe₃O₄@SiO₂ heterojunction nanocatalyst was successfully prepared.The synergistic effect between Ni/NiO makes the Ni-NiO/Fe₃O₄@SiO₂ catalyst show good activity in catalyzing the furfural hydrogenation reaction.Under the optimal reaction conditions（100°C,1 MPa,3 h,500 rpm）furfural was efficiently converted into THFA,the conversion was 100%,the yield was>97%,and the carbon balance was>91%.In addition,the Ni-NiO/Fe₃O₄@SiO₂ catalyst has good magnetic properties and can rapidly separate solid-liquid solutions after the reaction,so it has good application prospects.