Enhancement of Ni-NiO-CeO[sub.2] Interaction on Ni–CeO[sub.2]/Al[sub.2]O[sub.3]-MgO Catalyst by Ammonia Vapor Diffusion Impregnation for CO[sub.2] Reforming of CH[sub.4]

Ni-based catalysts have been widely used for the CO[sub.2] reforming of methane (CRM) process, but deactivation is their main problem. This study created an alternative electronic Ni-NiO-CeO[sub.2] interaction on the surface of 5 wt% Ni-5 wt% CeO[sub.2]/Al[sub.2]O[sub.3]-MgO (5Ni5Ce(xh)/MA) catalysts to enhance catalytic potential simultaneously with coke resistance for the CRM process. The Ni-NiO-CeO[sub.2] network was developed on Al[sub.2]O[sub.3]-MgO through layered double hydroxide synthesis via our ammonia vapor diffusion impregnation method. The physical properties of the fresh catalysts were analyzed employing FESEM, N[sub.2] physisorption, and XRD. The chemical properties on the catalyst surface were analyzed employing H[sub.2]-TPR, XPS, H[sub.2]-TPD, CO[sub.2]-TPD, and O[sub.2]-TPD. The CRM performances of reduced catalysts were evaluated at 600 °C under ambient pressure. Carbon deposits on spent catalysts were determined quantitatively and qualitatively by TPO, FESEM, and XRD. Compared to 5 wt% Ni-5 wt% CeO[sub.2]/Al[sub.2]O[sub.3]-MgO prepared by the traditional impregnation method, the electronic interaction of the Ni-NiO-CeO[sub.2] network with the Al[sub.2]O[sub.3]-MgO support was constructed along the time of ammonia diffusion treatment. The electronic interaction in the Ni-NiO-CeO[sub.2] nanostructure of the treated catalyst develops surface hydroxyl sites with an efficient pathway of OH* and O* transfer that improves catalytic activities and coke oxidation.