Construct Cu–Zn Interfaces and Cu 0/ + Sites over Al 2 O 3 -Supported Catalyst for Hydrogen Production

In the fabrication of Cu-based catalysts, inducing the formation of Cu0/+ sites and constructing the interfaces between Cu-containing species and promoters are particularly important for the development of high-performance catalysts but remain a challenge. Herein, an Al2O3-supported catalyst with abundant Cu–Zn interfaces and Cu0/+ sites was designed and successfully constructed by taking advantage of the competitive adsorption of Cu and Zn ions and applied in the methanol steam reforming (MSR) reaction. Based on the evolution of the microstructural and physicochemical properties of the catalyst before and after a 125-h reaction, the copromoting effect of rich in Cu–Zn interfaces and Cu0/+ sites, and uniform dispersion of small-sized Cu-containing species, as well as the excellent reducibility on the outstanding MSR performance was confirmed. Among all the comparative catalysts, the CZA co-imp. catalyst prepared by the co-impregnation method exhibited the relatively excellent activity, i.e., 92% conversion of methanol and 1.25% selectivity of CO at 230 °C. Importantly, the H2 productivity (997 mmolH2·molCu–1·min–1) and catalytic stability (decrease rate of conversion within 125 h was only 0.04%·h–1) of the optimized sample were 4-fold higher and 1 order of magnitude lower than that of the commercial one, respectively. Furthermore, the reforming process over an Al2O3-supported Cu–Zn catalyst involving methoxy, formate, and formaldehyde species was demonstrated by in situ TP-DRIFTS analysis. This study provides a feasible experimental reference for fabricating Cu-based catalysts related to the MSR reaction.