Sustainable Syngas Generation from Methane: Enhanced Catalysis with Metal-Promoted Nickel on Silica-Alumina Composites

The urgent challenge to mitigate fossil fuel emissions for environmental preservation has never been more crucial. Fossil fuels are a significant contributor to climate change because of their greenhouse gas (GHG) emissions. They have a significant negative impact on our environment. Burning fossil fuels releases heat-trapping greenhouse gases such as carbon dioxide, which worsens climate change. Additionally, the extraction processes for fossil fuels pollute the air we breathe by emitting harmful substances into the atmosphere. As a result, sustainable alternatives are necessary. One promising alternative is the dry reforming of methane (DRM), which converts two GHGs, CH₄ and CO₂, into syngas, a valuable chemical feedstock. However, efficient and selective DRM requires optimized catalyst performance. While existing research explores Ni catalysts for DRM, there is a gap in identifying optimal promoters that maximize conversion rates and achieve the ideal H₂/CO ratio for syngas production. To address this gap, we investigated Ni catalysts supported on silica-alumina (SiAl) composites, incorporating Ir, Rh, Ru, Pt, and Pd as promoters. We used a central composite design technique to optimize the DRM process. Characterization techniques, including N₂ adsorption, XRD, H₂-TPR, CO₂-TPD, Raman, TGA, SEM, and TEM, were used to analyze the catalysts' properties. Our research aimed to identify the most effective metal promoter for Ni catalysts in DRM, optimize the DRM process for high CH₄ and CO₂ conversion rates while achieving a suitable H₂/CO ratio for syngas production, and evaluate catalyst properties using various characterization techniques. Our results showed that Rh-promoted Ni catalysts displayed superior performance, achieving CH₄ (87.0%) and CO₂ (93.1%) conversion rates under optimized conditions. The H₂/CO ratio of 0.99 indicates ideal syngas composition. Characterization techniques confirmed these findings and revealed the catalysts' efficacy and durability.