Hydrogen production via methanol steam reforming over Au/CuO, Au/CeO2, and Au/CuO–CeO2 catalysts prepared by deposition–precipitation

Abstract

The production of hydrogen (H2) with a low concentration of carbon monoxide (CO) via steam reforming of methanol (SRM) over Au/CuO, Au/CeO2, (50:50)CuO–CeO2, Au/(50:50)CuO–CeO2, and commercial MegaMax 700 catalysts were investigated over reaction temperatures between 200°C and 300°C at atmospheric pressure. Au loading in the catalysts was maintained at 5wt%. Supports were prepared by co-precipitation (CP) whilst all prepared catalysts were synthesized by deposition–precipitation (DP). The catalysts were characterized by Brunauer–Emmett–Teller (BET) surface area, X-ray diffraction (XRD), temperature-programmed reduction (TPR), and scanning electron microscopy (SEM). Au/(50:50)CuO–CeO2 catalysts expressed a higher methanol conversion with negligible amount of CO than the others due to the integration of CuO particles into the CeO2 lattice, as evidenced by XRD, and a interaction of Au and CuO species, as evidenced by TPR. A 50:50 Cu:Ce atomic ratio was optimal for Au supported on CuO–CeO2 catalysts which can then promote SRM. Increasing the reaction time, by reducing the liquid feed rate from 3 to 1.5cm3h−1, resulted in a catalytic activity with complete (100%) methanol conversion, and a H2 and CO selectivity of ∼82% and ∼1.3%, respectively. From stability testing, Au/(50:50)CuO–CeO2 catalysts were still active for 540min use even though the CuO was reduced to metallic Cu, as evidenced by XRD. Therefore, it can be concluded that metallic Cu is one of active components of the catalysts for SRM.