Photothermal catalytic hydrogen production via methanol steam reforming on Cu/ZnO composites

Methanol steam reforming (MSR) is a reaction with great promise that enables the efficient generation and safe conveyance of hydrogen. Nevertheless, it needs a relatively high temperature to reach high activity, leading to considerable energy consumption. In the present study, Cu/ZnO catalysts synthesized via co-precipitation, hydrothermal, and incipient impregnation method were employed for photothermal catalysis MSR under low temperature. The catalysts were characterized by XRD, SEM, H-2-TPR, XPS, UV-vis, N2O titration, and N-2 adsorption-desorption at low temperature, etc. The results showed that the crystal size, structure and photoresponse of Cu/ZnO were influenced by different synthesis methods, and then affecting the photothermal catalysis MSR performance. The Cu/ZnO synthesized by the hydrothermal method demonstrated superior photothermal catalysis MSR performance due to its advantages such as relatively large specific surface area, pore volume, pore diameter, uniform distribution of active components, as well as strongest light absorption. Under the reaction conditions of a pressure of 0.1 MPa, a temperature of 240 degrees C, and a space velocity of 17,300 mL/(g<middle dot>h), the initial methanol conversion and hydrogen yield reached 94.65% and 92.51 mL/(g<middle dot>min), respectively. In-situ diffuse reflectance infrared Fourier transform spectra (DRIFTS) were employed to elucidate the reaction mechanism of the photothermal catalysis MSR. This research would provide significant understandings for the advancement of photothermal catalysis MSR for hydrogen production and in the domain of green chemistry.