Chitosan-Derived Porous N-Doped Carbon as a Promising Support for Ru Catalysts in One-Pot Conversion of Cellobiose to Hexitol
Xin Xiao, San Hua Lim, Wei Chu, Yan Liu
Abstract
Tailoring the metal properties over N-doped carbon materials is essential to lignocellulose/cellobiose hydrogenation reactions. In this contribution, using a facile Na2CO3-assisted mechanochemical synthesis approach and tuning the weight ratio of Na2CO3/CTS (chitosan), the surface properties of Ru, including metal particle size, dispersion, and surface Ru0/RuO2 species, were tailored by adjusting the metal–support interaction between Ru and the CTS-derived carbons for cellobiose hydrogenation. The total content of N was tunable with the weight ratio of Na2CO3/CTS, further moderating the metal–support interactions. Excellent catalytic performance at 95% of hexitol yield was achieved over the 0.75 wt %Ru/CTS-0.5 catalyst at 185 °C with a moderate N content. The results indicated that the dominated nitrogen species (pyridinic and oxidized N species) in CTS-x carbon worked as the anchor sites for Ru loading. The structure–performance analysis demonstrated that the metal dispersion of Ru and the relative content of surface-exposed Ru0 were sensitive to the total content of N and determined the catalytic performance in cellobiose hydrogenation. The insightful understanding may extend the CTS-derived N-doped carbon materials as ideal supports for a wide range of biomass hydrogenation.