Unravelling the synergistic promotion effect of simultaneous doping Fe and Cr into Cu-based spinel oxide on methanol steam reforming

Abstract

The effects of Fe and Cr species on Cu-based supported and spinel oxide catalysts during methanol steam reforming (MSR) reaction and the Cu–Fe–Cr synergy were investigated. Herein, a series of Al2O3 supported catalysts were prepared. And their MSR performance was evaluated. The addition of Fe and Cr had a significant promotion on MSR performance compared with the corresponding Cu-based catalyst. In order to unravel the beneficial effect, CuFe, CuCr, CuAl, CuFeAl, CuCrAl and CuFeCr catalysts were synthesized by the hydrothermal method. And BET, XRD, SEM-EDX mapping, HRTEM, H2-TPR, NH3-TPD, CH3OH-TPD and XPS characterizations were performed. Results showed that CuFeCr catalyst possessed superior MSR behaviors. At the temperature of 260–270 °C, its methanol conversion was maintained above 80% during a time-on-stream stability of 100 h. And it exhibited better fast start-up behaviors than commercial catalyst. In combination with the characterizations, it was assumed that the excellent catalytic performance of the CuFeCr catalyst was attributed to its moderate Cu+ content and Ovac/Oads ratio. And it was the result of the Cu–Fe–Cr synergistic effect.