The synergistic effect of a Ru-Cu bimetallic cocatalyst on anatase for methanol photocatalytic reforming.

Hydrogen (H2) has become a promising clean energy carrier due to its unique merits of high energy density and zero carbon emissions. Photocatalytic reforming of methanol is regarded as an efficient strategy for hydrogen production. Herein, we report the synthesis of Ru-Cu bimetallic-modified anatase TiO2 photocatalysts for efficient photocatalytic methanol reforming. By modulating the relative mass fractions of the bimetallic co-catalyst, a 1/6wt%Ru-5/6wt%Cu/TiO2 sample displayed an impressive H2 production rate, up to 1706 µmolg-1 h-1, which is 28 and 1.7 times that of pure TiO2 and 1wt%Cu/TiO2, respectively. Furthermore, the optimized 1/6wt%Ru-5/6wt%Cu/TiO2 matched the catalytic efficacy of the 1wt%Ru/TiO2 system while reducing noble-metal consumption by 80%, thereby demonstrating superior precious-metal atom economy. In addition, the Ru-Cu/TiO2 catalyst demonstrated excellent stability, showing no significant decrease in activity after five cycles of a photocatalytic reaction lasting 2 h for each cycle. The scavenging assays and in situ DRIFTS reveal that the intimate spatial and electronic synergy between Ru and Cu accelerates the surface reaction kinetics. These observations offer critical benchmarks for promoting solar-driven hydrogen evolution technologies utilizing liquid organic hydrogen carriers (LOHCs).