Journal of Industrial and Engineering Chemistry, Vol.124, 224-231, August, 2023
Selective aerobic-oxidation of glycerol to lactic acid over ruthenium-vanadium bimetallic catalysts
Ongoing trends to increase biodiesel production translates into enhanced surplus glycerol production, driving the need to develop value-added products, such as lactic acid, from glycerol. The present work is devoted to synthesizing Ru-V bimetallic and monometallic catalysts supported on activated carbon and testing them to produce lactic acid from glycerol through selective aerobic oxidation. The synthesized catalysts were thoroughly characterized to obtain morphological and structural properties, elemental composition, and surface area. The Ru-V2O5/AC (Ru-V/AC) bimetallic catalysts demonstrated superior performance to monometallic Ru and V catalysts, exhibiting a synergistic effect. The Ru-V/AC bimetallic catalyst containing 1.5 wt% Ru and 0.5 wt% V exhibited the best catalytic performance with a lactic acid yield of 75.5% at 98.7% glycerol conversion under mild operating conditions (1 NaOH/glycerol molar ratio, 4400 glycerol/metal molar ratio, 473 K temperature, 5 Bar air pressure and 3 h reaction time). The Ru-V/AC bimetallic catalyst showed good stability during the reaction with only a marginal loss in activity when reused for four consecutive cycles, suggesting that this catalyst can be recycled multiple times.