Ag substituted LaCoO3 perovskites as precursors for the catalytic hydrogenation of levulinic acid

BACKGROUND Perovskite-type mixed oxides with the formula La1-xAgxCoO3 (xAg = 0.05, 0.10, 0.20) were successfully used as precursors to prepare cobalt nanoparticle catalysts for use in the catalytic hydrogenation of levulinic acid (LA). The calcined, reduced, and post reaction catalysts were characterized by X-ray diffraction, N-2 adsorption isotherms at -196 degrees C, H-2-Temperature programmed reduction, NH3-Temperature programmed desorption, H-2 chemisorption, and X-ray photoelectron spectroscopy. The catalytic performance was evaluated in a batch reactor at 50 bar of H-2 at different temperatures to determine the kinetic parameters. RESULTS An increase in the reducibility of the perovskite and Co3+ species contents was detected upon the silver doping. The highest catalytic activity was observed for the perovskite with xAg = 0.20 and this activity was attributed to the high content of metallic cobalt. CONCLUSION The active site corresponds to surface metallic cobalt and the presence of silver increases the amount of reduced cobalt. The high hydrogenating capacity of metallic cobalt explains the 100% selectivity towards gamma valero lactone of the synthesized catalysts. (c) 2022 Society of Chemical Industry (SCI).