Surface NiOCe Formation After CeO ₂ Incorporation Markedly Improves Photothermocatalytic Cellulose Steam Reforming Over Ni/SiO ₂

Photothermocatalysis offers a green and sustainable pathway for biomass resource utilization. Herein, a catalyst (denoted as Ni/Ce 2.5 –S) of Ni dispersed on amorphous mesoporous SiO 2 modified by trace CeO 2 nanoparticles (NPs) was prepared. By photothermocatalytic cellulose steam reforming on Ni/Ce 2.5 –S, high production rates of H 2 and CO (3283.9 and 1918.0 mmol g catalyst −1 h −1 , respectively) are achieved. The excellent photothermocatalytic performance originates from the formation of NiOCe bonds due to the partial surface reconstruction of CeO 2 NPs by Ni modification, which donate plentiful active lattice oxygen (O L ) to the reaction. Moreover, the resulting oxygen vacancies (O V ) enhance H 2 O adsorption, thus facilitating the involvement of H 2 O in the reaction, effectively suppressing byproducts formation, and improving syngas yield. Concurrently, Ni NPs function as broadband plasmonic absorbers that convert solar photons into intense local heat, while the excitation of photon‐induced NiO bonds, particularly NiOCe bonds, notably promotes the decomposition of carbonaceous intermediates (C x H y O z ), their subsequent reaction with H 2 O, and the steam gasification of char. These effects collectively drive exceptional photothermocatalytic performance.