Preparation Of Ni/hydrothermal Carbon Catalyst And Its Hydrogenation Performance For 5-hydroxymethylfurfural

5-hydroxymethylfurfural(HMF)is a promising platform chemical,which can be obtained from abundant bio-resources.The C=O,C-O and furan ring of HMF make it flexible for transformations by hydrogenation.Among the products,2,5-dimethylfuran(DMF)and 2,5-dimethyltetrahydrofuran(DMTHF)have been identified as promising liquid fuel candidates with high energy density and octane number.Besides,2,5-dihydroxymethylfuran(DHMF)and 2,5-dihydroxymethyltetrahydrofuran(DHMTHF)could also be obtained for polymer synthesis.Thus,selective hydrogenation of HMF is of great significance for future energy and chemical supply.The main results are summarized as follows:In this work,the hydrothermal carbon(HC)was prepared via a hydrothermal method and used as a support for the Ni-based catalysts.The hydrothermal carbon has a large specific surface area and also contains some oxygen-containing functional groups to facilitate the dispersion and anchoring of Ni.The selectivity of2,5-di(hydroxymethyl)furan(DHMF),2,5-dimethyltetrahydrofuran(DMTHF),and2,5-dimethylfuran(DMF)were tuned by modulating the Ni nanoparticle sizes.By appropriate tuning of the reaction conditions,either DMF or DHMF were obtained in good yields.5%-Ni/HC and 10%-Ni/HC resulted the best catalyst for this purpose,DMF+DMTHF obtain yields up to 94.6% and obtain DHMF selectivity up to 94%,respectively.Moreover,the characterizations show that both Ni and Ni O existed on the surface of the catalysts.We speculate that the synergy between Ni and Ni O could also promote the selective hydrogenolysis of HMF to DMF and DMTHF.According to the experimental results in the previous chapter,it is found that although nickel-based catalysts can obtain DMF,the reaction conditions are relatively harsh.We have designed a bimetal catalyst Ni Al/HC.Decomposition of the site and reaction conditions achieved a yield of 96.3% of 2,5-Bishydroxymethyltetrahydrofurane and89.3% of 2,5-dimethyltetrahydrofuran.This work decomposes the metal-acid site equilibrium inherent to the C = O/ C-O hydrogenolysis reaction.