Nanoceria supported palladium(0) nanoparticles: Superb catalyst in dehydrogenation of formic acid at room temperature

Highly efficient dehydrogenation of formic acid (FA) at room temperature was achieved using palladium(0) nanoparticles supported on nanoceria (Pd-0/CeO2) as catalysts. Pd-0/CeO2 was prepared by impregnation of palladium(II) ions on the surface of ceria followed by their reduction with sodium borohydride in aqueous solution at room temperature. Pd((0)/CeO2 was isolated from the reaction solution by centrifugation and characterized by a combination of advanced analytical techniques. The catalytic activity of Pd-0/CeO2 samples with various Pd loading in the range 1.0-5.0% wt was tested in dehydrogenation of formic acid plus sodium formate with a molar ratio of FA/SF = 1/9. Pd-0/CeO2 with Pd loading of 2.27% wt shows superb catalytic activity in dehydrogenation of FA with a turnover frequency (TOF) value of 1400 h(-1) at 25.0 +/- 0.1 degrees C. The superb catalytic activity of Pd-0/CeO2 is ascribed to the reducible nature of ceria during the decomposition of FA (HCO2H -> CO2+H-2). The kinetic data, obtained by measuring the volume of pure H-2 gas, could be converted to the change in concentration of FA by considering the equilibrium between the formate ion and formic acid (HCO2H reversible arrow HCOO- + H3O+). The FA concentration versus time data fit to the first order kinetics with respect to the FA concentration. (C) 2017 Elsevier B.V. All rights reserved.