(632f) Enhancing the Activity and Stability of Nickel-Supported Catalysts for Dry Reforming of Methane Using Halloysite Nanotubular Clay As a Support

Greenhouse gases, such as methane (CH₄) and carbon dioxide (CO₂), contribute to climate change, therefore reducing their effects has become a crucial challenge. Dry reforming of methane (DRM) can convert CH₄ and CO₂ to synthetic gas, but catalyst deactivation limits the process. In catalysis, nickel represents an ideal candidate as cheaper alternative to noble metals, but it suffers from coke formation and sintering at high temperatures. Using appropriate support and preparation methods play a major role in improving the activity and stability of Ni supported catalysts. For example, surface treatment of natural clays such as halloysites is one of the strategies explored to enhance nickel catalyst stability. In this study, halloysite nanotubular (HNT) clay is utilized as a support for Ni deposition. Here, efforts are made to activate the surface of HNT with acids (HNO₃ and H₂SO₄) and alkalis (Na₂CO₃ + NaNO₃ and NaOH) prior to Ni doping to assess the effect of support treatment on the stability, and activity of the catalyst. 10 wt% Ni catalysts on raw, acid, and alkali treated-HNT supports were prepared via the wet impregnation method. The as-prepared catalysts were characterized using X-ray diffraction, BET surface area, scanning electron microscopy, transmission electron microscopy, X-ray photo electron spectroscopy, H₂-Temperature Programmed Reduction, CO₂-Temperature Programed Desorption, and Temperature Programmed Oxidation. The catalyst morphology, chemical structure, and performance testing of the developed catalysts are presented. Ni doped NaOH-treated HNT showed a more than 2-fold increase in surface area (SA > 115 m²/g) compared to Ni-raw and Ni-HNO₃ treated HNT, with small Ni nanoparticle size (9 nm) and uniform distribution. In addition, it yielded higher basic sites and stronger Ni interaction, resulting in more stable catalyst compared to acid treatment with conversions (> 90%) and minimal coke formations. HNT could be an effective support for Ni catalysts in DRM reactions.