Design Metal Catalyst For Cellulose Hydrolysis And Hydrogenation, Hydrogenation Of Methyl Acetate Applications

Catalyst is an important material which is able to improve the rate of chemicalreaction and doesn’t minimize the weight of itself in the course of reaction.Nano-metal catalyst is one of the most important heterogeneous catalysts, andmainly used for hydrogenation, dehydrogenation, and oxidation. Transition metalsare effective hydrogenation and dehydrogenation catalysts, and can be divided intoprecious metals （mainly platinum, palladium, ruthenium, rhodium, etc.） and thenon-precious metals （iron, cobalt, nickel, copper, etc.）. Combining nanotechnologywith catalysis science to prepare catalysts having excellent catalytic activity andselectivity has become one of the main directions among the catalytic researchworkers. The Nano-metal highly dispersed on a high specific surface area of themesoporous materials, not only can increase the metal dispersion and thermalstability, but also the catalyst has a suitable pore structure, shape, and mechanicalstrength. This article is focused on the relationship between the structure and activity.（1） A series of solid acid catalysts and Ru/C metal catalyst were prepared andused for hydrothermal catalytic conversion of cellulose under hydrogenationconditions. It was found that the highest activity was achieved on the2wt%Ruloaded on the activated carbon treated with concentrated nitric acid; however, thehexitol yield is still low. In order to get high hexitol yield, we designed a series of thesolid acid catalyst to promote the catalytic performances of Ru-based catalyst forhydrolysis-hydrogenation of cellulose. Commercial available silica was used as hardtemplate to prepare mesoporous carbon via reverse copy and then the as-preparedmesoporous carbon was sulfonated to get solid acid. By combining the solid acidwith the as-prepared Ru/C, higher hexitol yield can be achieved for one stephydrolysis-hydrogenation of cellulose.（2） The Cu/MgO catalyst was prepared by precipitate depositing method,showing high activity, selectivity and stability during the gas-phase hydrogenation ofmethyl acetate to ethanol. It was found that the catalytic activity increased withincreasing the active surface area of the copper, and when the copper loading was14.8wt%, the copper surface area was maximum. Further increase the loading of copper led to agglomeration of copper species, resulting in decrease in activity.（3） In order to improve the stability of the catalyst, a Cu/SiO₂catalyst wasprepared by in situ ammonia-evaporation （AE） method. The formation of coppersilicate can be confirmed by IR analysis, which improved the dispersion degree ofcopper species, and, on the other hand, increased the interaction between the copperspecies and the carrier. When the copper loading was12.4wt%and the calcinationtemperature was623K, the conversion of methyl acetate and selectivity to ethanolwere more than99%and98%at reaction temperature of503K.