5Ni/MgO and 5Ni/MgO + MOx (M = Zr, Ti, Al) Catalyst for Hydrogen Production via Dry Reforming of Methane: Promotor-Free, Cost-Effective, and Handy Catalyst System

Utilization of CO2 as a promising oxidant under dry reforming methane (DRM) can mitigate two greenhouse gases (CO2 and CH4) together, as well as DRM reaction may be a source of H-2 energy in future. The cost-effective and handy catalyst preparation procedures like mixing, drying and calcining may turn this reaction from lab to industry. In this line, herein, 5Ni/MgO and 5Ni/MgO + MOx (M = Zr, Ti, Al) catalysts were prepared, investigated for DRM and characterized by X-ray diffraction, Raman, temperature programmed reduction/desorption, thermogravimetry and transmission electron microscope. Among the prepared catalysts, the 5Ni/MgO + TiO2 catalyst exhibits the highest concentration of active Ni sites enhanced reducibility under oxidizing and reducing environments, but catalytic excellency is hindered by severe graphitic-type coke deposition. On the other hand, the 5Ni/MgO + Al2O3 catalyst predominantly comprises metallic Ni resulting from the reduction of "strongly interacted NiO", expanded surface area and the highest concentration of easily accessible active sites, contributing to its superior performance (H-2 yield similar to 71% up to 430 min time on stream) under oxidizing and reducing conditions during DRM. The outstanding performance of the 5Ni/MgO + Al2O3 catalyst marks a significant stride towards the development of an industrially viable, cost-effective, and convenient catalyst system for DRM.