Enhancing catalytic performance, coke resistance, and stability with strontium-promoted Ni/WO3-ZrO2 catalysts for methane dry reforming

The first step of the DRM reaction is just the decomposition of CH4 into CH4-x (x = 1-4). The next step comprises two steps, namely the oxidation of CH4-x into syngas (by CO2) and the self-polymerization of CH4-x species. The earlier one is known as dry reforming of methane (DRM), and the latter one generates carbon deposits over the catalyst surface. In this study, we investigated the impact of 1-3 wt% Sr over Ni-based catalysts on a ZrO2-WO3 support on the catalytic activity and coke deposit. Various characterization techniques such as thermogravimetric analysis, X-ray diffraction, Raman spectroscopy, temperature-programed oxidation, temperature-programed reduction, and temperature-programed desorption were used to assess the physicochemical properties of the fresh and spent catalysts. The addition of 2wt% Sr promoter significantly improves the catalyst's basicity in strong basic sites region through Sr2+ mediated interaction of CO2 species as well as inhibits the deposition of carbyne type carbon. Enhanced CO2 interaction results into the potential oxidation of carbon deposit and the highest CH4 conversion, reaching 60% up to 470 min TOS at a reaction temperature of 700 degree celsius.