TiO ₂ Supporting Cu–Au Alloy Nanoparticles for Photocatalytic Methanol Reforming to Hydrogen Production

Methanol steam reforming (MSR) is a promising approach for hydrogen production, allowing for efficient production and safe transportation of hydrogen via liquid methanol. However, it requires relatively high temperatures to achieve high activity, resulting in huge energy consumption. In this study, a plasma copper-gold alloy catalyst supported on titanium dioxide was synthesized via the impregnation method followed by high-temperature calcination. The resulting nanoparticles exhibited an average size of approximately 12 nm, and their composition was controlled by adjusting the molar ratio of the precursor materials. The synthesized CuAu-TiO₂ catalyst facilitates efficient solar-driven MSR without the need for additional thermal input. The optimized catalyst achieves a continuous hydrogen production rate of 78 µmol·g^-1·h^-1, with a solar energy conversion efficiency of 2.66%. We determined that the maximum conversion rate under photochemical catalysis conditions can reach 90.6%. We verified that the plasmon-induced hot carriers could catalyze the methanol steam reforming reaction at temperatures significantly lower than those required for traditional thermal catalysis, releasing hydrogen. Post-reaction, the catalyst can be recovered and reactivated for repeated use. This work provides a valuable demonstration for the development and application of future light-driven clean energy conversion systems.