Regulating Carbon Vacancies and Undercoordinated Mo Sites in Mo₂C Catalysts Toward Photo-Thermal Catalytic Conversion...

The conversion of biomass into chemical fuels is exciting but quite challenging in the development of an effective conversion strategy to generate easily-separated products without energy consumption. Herein, a lignocellulosic biomass-to-H₂ conversion system via photo-thermal catalysis over Mo₂C hierarchical nanotube catalysts in an acidic solution, in which the lignocellulose is hydrolyzed to small organic molecules (such as glucose, etc) by dilute H₂SO₄, and then the resulting glucose is oxidized by Mo₂C catalyst to generate H₂ are reported. During the photo-thermal catalytic processes, the carbon vacancy in Mo₂C catalysts results in the generation of undercoordinated Mo sites, which act as active sites for both biomass oxidation and H₂ generation reactions. Thus, the successful photo-thermal catalytic conversion of common agricultural and forestry biomass including polar wood chip, bamboo, wheat straw, rice straw, corncob, and rice hull into H₂ fuel is realized, and the highest H₂ generation rate achieves 30 µmol g^-1 h^-1 in the wheat straw system. Outwork affords efficient noble-metal-free catalysts with adjustable active sites for photo-thermal catalytic conversion of lignocellulosic biomass into H₂.