Study On The Preparation Of Pd-based MOFs Derivative Catalyst And Its HMF Selective Hydrogenation

Catalytic conversion of biomass derived compounds into different platform chemicals and liquid fuels is an important way to reduce global dependence on fossil resources.In the past few decades,biomass-derived 5-hydroxymethylfurfural?HMF?has received extensive attention for its wide range of applications in the production of industrially important value-added chemicals and fuel assemblies.This paper provides a new approach to design a catalyst,using pyrolysis MOFs derivatives as supports,and through the modulation method of preparation design highly dispersed,more active sites of the noble metal catalyst,sure to highly active results in selective hydrogenolysis reaction,high selectivity and high stability simultaneously.Various characterization methods?XRD,SEM,HRTEM,Raman,XPS etc.?were used to research systematically the structure of catalyst-nature-the relationship between the catalytic activity,and put forward the possible reaction mechanism.?a?A Pd Zn/porous Zn O nanocatalyst was designed and developed by pyrolysis of nano-ZIF-8 and a subsequent impregnation of Pd.The Zn O inherits the original morphology and porous structure of ZIF-8 and has a good dispersion of Pd.Most Pd exists in the active phase of Pd Zn alloy.This catalyst has excellent performance in selective hydrogenation of HMF to 2,5-bis?hydroxyl-methyl?furan?BHMF?.Abundant oxygen vacancies derived from ZIF-8 improved the effective adsorption of C=O bond in the reactant,and enhanced the charge transfer and adsorption desorption selectivity of the catalyst.The conversion was 94.1%and the selectivity of BHMF was 93.5%under mild conditions without any additives.And it still maintains good activity after seven runs.Even more remarkable,the catalyst has significant catalytic properties in the hydrogenation of other unsaturated aldehydes to their alcohols.?b?Co-Co Ox-containing N-doped porous carbon-supported palladium catalysts were prepared via ZIF-67 pyrolysis and a simple impregnation route.The material was employed for the hydrogenolysis of 5-hydroxymethylfurfural?HMF?to 2,5-dimethylfuran?DMF?.The Co-Co Ox-containing N-doped porous carbon provides a high dispersion and anchoring effect on active metal as well as abundant surface defects with strong adsorption ability to the oxygenated groups and enhanced electron transfer capability,which could promote the activation and H₂ spillover and the cascade reaction of HMF hydrogenolysis to DMF at a yield of 98.7%.As-obtained palladium-based nano-catalysts exhibited excellent catalytic hydrogenolysis performance,and there is no obvious change in activity in 6 runs.Such high catalytic efficiency could reasonably be attributed to the surface synergism between surface defects and active metallic species.Most importantly,the present strategy enables us to tune the surface physicochemical properties of catalysts for designing new bifunctional catalysts with significantly enhanced catalytic performance.