Catalytic transfer hydrogenation of CO2 to formic acid with glycerol as the hydrogen donor over Ru-REUSY catalysts

Abstract

In this work, a "hydrogen-free" strategy based on the ruthenium (Ru) modified REUSY molecular sieve catalysts was proposed, which can promote CO2 catalytic transfer hydrogenation using endogenous hydrogen induced by glycerol dehydrogenation. As the active component, Ru can not only act on the dehydrogenation reaction with glycerol, but also promote the hydrogenation reaction of CO2. Comparison experiments confirmed that under conditions of 200 °C, 36 h, and 7.92 g KHCO3, the reaction could obtain the highest yields over 10 wt.% Ru-deAl(5 h)-REUSY. The yields of formic acid and lactic acid were 19.81 % and 6.13 % respectively. In addition, when replacing the carbon source from KHCO3 to CO2 (dry ice), formic acid and lactic acid yields over 10 wt.% Ru-deAl(5 h)-REUSY catalysts were further improved, reaching 64.14 % and 17.13 %, respectively. This work demonstrated the feasibility of the "hydrogen-free" upgrade process realizing the catalytic transfer hydrogenation of CO2 into formic acid with glycerol as hydrogen donor.