Enhanced H₂O adsorption by Ca²⁺ doping substantially improves the catalytic performance for light-driven thermocatalytic steam cellulose reforming on Ni/Ca_1/8-SiO₂

Using renewable biomass to produce syngas can form a closed carbon cycle, curbing carbon emissions. However, thermocatalysis suffers from high energy consumption, while the reaction rates of photocatalysis are relatively low. Here, we report the light-driven thermocatalytic steam cellulose reforming to hydrogen-rich syngas on the Ni nanoparticles loaded on Ca2+ doping SiO2 (Ni/Ca-1/8-SiO2). It exhibits a high production rate of hydrogen-rich syngas (H-2 3059.4 and CO 1612.1 mmol g(catalyst)(-1) h(-1)) and good cycling durability. Tar from cellulose pyrolysis, which is inherently challenging to prevent, is substantially decreased by the involvement of H2O. Ca2+ doping dramatically enhances H2O adsorption, resulting in a significant improvement in catalytic performance. The efficient light-driven thermocatalysis derives from the strong absorption over the whole solar spectrum of Ni/Ca-1/8-SiO2 on the one hand. On the other hand, noticeable photoactivation effect is observed to promote the oxidation of carbon species by oxygen due to the surface Ni-O bonds being activated upon light illumination.