Lignocellulosic biomass conversion into CO and H2 via sunlight-enhanced lattice oxygen recycling in perovskite oxides

Converting biomass to syngas (CO + H2) is an accessible way to incorporate renewable carbon into the sustainable chemical industry. However, due to insufficient C–C bond breaking even at high temperature, biomass reforming produces syngas with a reduced yield accompanied by the formation of tar, char, and complex side-products. Herein, irradiation of perovskite La0.6Sr0.4Co0.2Fe0.75Ru0.05O3−δ (LSCFR) by concentrated sunlight activates thermodynamically stable lattice oxygen, thereby increasing the fraction of activated lattice oxygen from 12 % to 43 %. This enhanced oxidation ability enables biomass conversion to COx in 96 % yield alongside H2 production. Sunlight irradiation also facilitates lattice oxygen replenishment via CO2 reduction, allowing dry photoreforming of biomass over LSCFR. In a flow apparatus, the dry photoreforming affords CO and H2 in 80 % and 41 % yields, respectively, producing 0.15 and 0.06 m3 of CO and H2 in 20 h. This work reveals the light-responsive oxidation ability of oxides for the sustainable refining of native biomass.