Improving the efficiency of Ru metal supported on SiO2 in liquid-phase hydrogenation of gluconic acid by adding activated carbon

Abstract

Improving the efficiency of heterogeneous catalytic reactions is essential for enhancing the production efficiency of highly sustainable biorefineries. As a feedstock of biorefineries, alginic acid, which is a major component of brown algae, is converted into high value-added sugar alcohols such as sorbitol via hydrolytic hydrogenation over a Ru-based heterogeneous catalyst. In this study, Ru catalysts loaded on various supports such as activated carbon (AC), SiO2, TiO2, and Al2O3 were prepared and applied in the liquid-phase hydrogenation of gluconic acid – an intermediate in the hydrolytic hydrogenation of alginic acid. When AC was mixed as an additive with the oxide-supported Ru catalysts, the turnover rate of Ru in the hydrogenation of gluconic acid increased threefold, particularly for Ru/ SiO2. According to various analyses, AC can uptake more spilt-over hydrogen from Ru and exhibit superior adsorption ability for reactants compared to other metal oxides, thereby providing additional catalytically active sites. The simple strategy of adding pristine AC resulted in significantly enhanced turnover rate of the oxide-supported Ru catalyst, which is a significant breakthrough for sustainable biorefinery processes.