Ru／CNTs高效催化转化纤维二糖制备山梨醇

Efficient Conversion of Cellobiose into Sorbitol over Ru/CNTs Catalyst

针对纤维素的转化,以纤维二糖催化加氢制备山梨醇为模型反应,研究了负载Ⅷ及IB族金属催化剂的催化性能.研究发现,在测试的金属组分中,负载Ru、Ir催化剂显示了较高的转化纤维二糖生成山梨醇性能.在使用碳纳米管(CNTs)、活性炭(AC)、Al_2O_3、HY、SiO_2、CeO_2、MgO等不同载体制备的催化剂中,Ru/Al_2O_3及Ru/CNTs显示较高山梨醇收率.在185℃中性水溶液中,最佳催化剂Ru/CNTs上的山梨醇收率为87%.初步探讨了Ru/CNTs催化剂上纤维二糖转化为山梨醇的反应途径.纤维二糖首先主要通过加氢反应生成3-β-D-吡喃糖醇,而后,3-β-D-吡喃糖醇水解为山梨醇和葡萄糖,而生成的葡萄糖可以迅速加氢转化为山梨醇.山梨醇还可异构为甘露醇和降解生成其它低碳醇.

As a model reaction for cellulose transformation,the conversion of ceUobiose was studied over supported metallic VIII and IB group elements catalysts,and Ru and Ir were found effective for the formation of sorbitol. Catalytic performances of catalysts on different supports including CNTs, AC, Al2O3, SiO2, H Y, CeO2, MgO showed that CNTs is the most suitable support for metallic Ru species, and a superior performance obtained was 87 % yield of sorbitol from the conversion of eellobiose over Ru/CNTs catalysts. The reaction route of cellobiose conversion was proposed. Firstly,cellobiose is transformed into 3-β-D- glucopyranosyl-D- glucitol by hydrogenation. Next,this 3-β-D-glucopyranosyl-D-glueitol was hydrolyzed to sorbitol and glucose which could be hydrogenated to sorbitol very quickly. However,the sorbtiol could also be converted by degradation or isomerization.