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 CH_4−x (x = 1–4). The next step comprises two steps, namely the oxidation of CH_4−x into syngas (by CO₂) and the self-polymerization of CH_4−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 ℃.