Oxidative steam reforming of methanol over CuO/ZnO/CeO2/ZrO2/Al2O3 catalysts

The composition (CuO/ZnO/Al2O3 = 30/60/10) of a commercial catalyst G66B was used as a reference for designing CuO/ZnO/CeO2/ZrO2/Al2O3 catalysts for the oxidative (or combined) steam reforming of methanol (OSRM). The effects of Al2O3, CeO2 and ZrO2 on the OSRM reaction were clearly identified. CeO2, ZrO2 and Al2O3 all promoted the dispersions of CuO and ZnO in CuO/ZnO/CeO2/ZrO2/Al2O3 catalysts. Aluminum oxide lowered the reducibility of the catalyst, and weakened the OSRM reaction. Cerium oxide increased the reducibility of the catalyst, but weakened the reaction. Zirconium oxide improved the reducibility of the catalyst, and promoted the reaction. A lower CuO/ZnO ratio of the catalyst was associated with greater promotion of ZrO2. The critical CuO/ZnO ratio for the promotion of ZrO2 was approximately 0.75–0.8. Introducing of ZrO2 into CuO/ZnO/Al2O3 also improved the stability of the catalyst. Although Al2O3 inhibited the OSRM reaction, a certain amount of it was required to ensure the stability and the mechanical strength of the catalysts.