Making H 2 from Light and Biomass over Ni/Mo 2 C Catalysts under Mild Conditions

Photothermal reforming of biomass to H2 has emerged as a promising strategy for biomass utilization but remains an enormous challenge to construct an efficient conversion system under mild conductions. Here, Ni-coated Mo2C microsphere (Ni/Mo2C) composites with an electron-depletion Ni (Niδ+) region and an electron-accumulation Mo2C (Mo2Cδ-) region were developed as efficient catalysts for photothermal reforming of biomass to H2 in neutral aqueous solution. In Ni/Mo2C catalysts, the Niδ+ region acted as efficient Lewis acidic sites to be used as active sites for biomass oxidation, while Mo2Cδ- can be used as active sites for the H2 generation reaction, which enhances the photothermal catalytic activity of Ni/Mo2C catalysts for biomass-to-H2 conversion. As a result, common plant biomass was successfully converted to H2 by Ni/Mo2C catalysts in neutral aqueous solution with the maximum H2 evolution rate of 117 μmol g-1 h-1 in the wheat straw system under 300 W Xe lamp irradiation.