Preparation Of Co-Based Catalysts And Their Application In Hydrodeoxidation Of Aromatic Alcohols And5-Hydroxymethylfurfural

Biomass can be effectively converted into bio-oil（mixtures of aromatic ketones,aldehydes,alcohols,hydrocarbons and other small molecules）via pyrolysis.Hydrodeoxygenation（HDO）of bio-oil could generate important chemicals and high-quality liquid fuels,reducing our dependence on fossil resources.Noble metal-based catalysts are often used to catalyze such reactions.However,they are not only expensive,but also lead to side reactions and excessive hydrogen consumption.Non-noble metal-based catalysts have low activity and need harsh reaction conditions.Therefore,it is of great significance to design catalysts with low cost and good performance.In this paper,a cheap metal cobalt-based catalyst was designed for HDO reactions of aromatic alcohol compounds and 5-hydroxymethylfurfural（HMF）.The research contents and innovation points are as follows:（1）Preparation of Co@CN-700 catalyst and its catalytic performance for aromatic alcohol HDO reactionUsing ZIF-67 as the precursor,porous carbon-nitrogen material-supported Cocatalyst Co@CN-x was designed and prepared（x represents the calcination temperature during the preparation of the catalyst,℃）.A number of characterizations were carried out,and its catalytic performance for the HDO reaction of various aromatic alcohol compoundswas studied.The results showed that the catalyst had good catalytic performance for this kind of reaction.Using Co@CN-700 as catalyst and mild reaction conditions（120℃,2 MPa H₂,8 h）,the selective HDO of C-OH bonds was achieved without changing the aromatic ring.In most cases,the yield of the target compound was more than 99%.Doping nitrogen on the carbon framework of catalyst significantly improved the yield of the target product,which provides a new method for non-noble metal catalyst to efficiently catalyze aromatic alcohol HDO reaction.（2）Preparation of CoC@Mn catalyst and selective catalytic hydrogenation of HMFOn the basis of the study of Co@CN-700 catalyst,the catalyst CoC@Mn was prepared by adding transition metal Mn to modify ZIF-67.It was shown that the catalyst had excellent catalytic performance for the hydrogenation of HMF to 2,5-dimethylfuran.Under the optimized reaction conditions（140℃,2 MPa H₂,8 h）,the single product 2,5-dimethylfuran（yield up to 99%）was obtained with high selectivity.Detailed characterization indicated that CoC@Mn had a large specific surface area and large pores,which was conducive to the high efficiency of the catalyst.The synergistic effect of metallic cobalt and manganese also improved the catalytic performance.In addition,the catalyst could be easily recycled and reused.This work provides a new route for the catalytic conversion of biomass platform compounds HMF.