ToF-SIMS study of the surface of catalysts used in biomass valorization

摘要

Hydrolytic hydrogenation of cellulose toward fuel additive - γ-valerolactone (GVL) - has been studied, and the catalytic performance of Pt/TiO_2 and Ru/TiO_2 and reaction conditions were optimized. Additionally, new information about the changes of catalyst surface after the reactions of lignocelulose toward GVL was obtained. Two procedures were investigated: one-pot hydrolysis-hydrogenation and hydrolysis of cellulose followed by hydrogenation in two separate reactions. Spent catalysts were tested by time-of-flight SIMS (ToF-SIMS). Reaction conditions strongly influence the GVL yield, which was much lower during one-pot procedure where much higher carbon deposit and catalyst deactivation was observed by ToF-SIMS and temperature-programmed reduction. Ruthenium catalysts were more active than platinum ones in liquid phase reactions toward GVL, independently of the feedstock.