Key role of light in highly efficient photothermocatalytic steam cellulose reforming on Co/CeO2–Al1Mg3O4.5

Photothermocatalysis provides an effective approach to sustainably produce renewable fuels by utilizing the energy of the whole solar spectrum. Here, merely with focused solar spectrum illumination, highly efficient photothermocatalytic steam cellulose reforming is achieved on Co/CeO2–Al1Mg3O4.5. The catalyst exhibits extremely high H2 and CO production rates (3374.4 and 1872.1 mmol gcatalyst−1 h−1) along with a 7.8% light-to-fuel efficiency, attributed to the light-driven thermocatalytic process on Co nanoparticles that utterly differs from traditional photocatalysis. The undesired tar mainly produced by cellulose pyrolysis is substantially reduced by the reaction of H2O with carbon-containing species. The active lattice oxygen (Olattice) of CeO2 is involved in the reaction by transferring to the surface of Co nanoparticles (Co NPs) loaded on the CeO2. The oxygen vacancies left on the surface of CeO2 nanoparticles can subsequently be replenished by oxygen from H2O dissociation, thus substantially enhancing the reaction of H2O with carbon-containing species, which is key to improving catalytic activity and reducing undesired tar yield. In addition to being the single heating source, the illumination exhibits a significant photoactivation effect on promoting the Olattice of CeO2, and surface oxygen species of Co NPs to react with the carbon-containing species, thus considerably facilitating the reaction of H2O with carbon-containing species.