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采用超临界甲醇处理活性炭,传统水浸渍制备负载钌炭催化剂,用N2物理吸附、Boehm滴定、X光电子能谱仪(XPS)、程序升温还原(TPR)、扫描电镜(SEM)、透射电镜(TEM)等表征手段,研究了超临界甲醇处理活性炭对活性炭表面结构、表面基团含量,及Ru/C催化剂的还原性能、钌的分布的影响.并以葡萄糖加氢生产山梨醇为模型反应对负载钌基催化剂的性能进行了评价.研究结果表明,超临界甲醇处理活性炭,活性碳的孔结构性能变化不大,但可有效降低活性炭表面含氧酸性基团的含量,有效提高钌的分散度,使催化剂的还原温度升高,增强了载体和活性组分钌间的相互作用,提高了钌的电子结合能,从而有效的提高所负载催化剂的催化活性.在实验范围内,当超临界甲醇的温度为300℃,处理时间为12 h以上时,在4.0 MPa,120℃,葡萄糖浓度为50%(w/w)反应条件下,催化剂的反应速率达到了118.65 mmol.min-1g-1Ru,是未处理活性碳的1.96倍.
The catalysts were characterized by N2 adsorption, Boehm titration, XPS, TPR, TEM and TEM (TEM) ) Were used to characterize the effect of supercritical methanol treatment on the surface structure of activated carbon, the content of surface groups, the reduction performance of Ru / C catalyst and the distribution of ruthenium. The sorbitol production by glucose hydrogenation Ruthenium-based catalysts were studied.The results showed that the pore structure properties of activated carbon and activated carbon treated with supercritical methanol showed little change, but could effectively reduce the content of oxygenated acidic groups on the surface of active carbon and effectively improve the dispersion of ruthenium, The temperature of the catalyst is increased, the interaction between the support and the active component of ruthenium is enhanced, the electron binding energy of the ruthenium is increased, and the catalytic activity of the catalyst is effectively increased.In the experimental range, when the supercritical methanol When the reaction temperature is 300 ℃ and the treatment time is above 12 h, the reaction rate of the catalyst reaches 118.65 mmo under 4.0 MPa, 120 ℃ and 50% (w / w) glucose concentration l.min-1g-1Ru, 1.96 times that of untreated activated carbon.