Catalytic Conversion of CO2 to Methane Using Nickel-Functionalized Mesoporous SBA-1 with 3D Cage-Type Porous Structure

Abstract

Developing efficient heterogeneous catalysts for activating CO₂ is of considerable interest for achieving carbon neutrality. Therefore, many researchers have devoted a lot of effort to design and develop various porous materials-based catalysts for CO₂ conversion. Catalysts with high activity and stability for CO₂ conversion are crucial for easy commercialization, but it remains a significant challenge to develop these catalysts. Herein, we report the fabrication of Ni-functionalized mesoporous silica with 3D mesoporous structure, cage-type pores, and different Ni contents for achieving enhanced CO₂ methanation and stability. The highly ordered mesoporous structure of SBA-1 offers a high surface area (1315 m² g⁻¹) that helps to anchor a significant amount of nickel nanoparticles. Insight into the structure of the catalyst and fine-tuning of metal-support interaction were in-depth, characterized by the combination of X-ray diffraction, electron imaging, and spectroscopic tools. The prepared Ni-functionalized SBA-1 materials exhibit an ordered mesoporous structure and the specific surface area decreases with increasing the concentration of the Ni on the porous channels of SBA-1. The optimized Ni-functionalized SBA-1 yielded 80.1% conversion with a CH₄ selectivity of 96.9% at a gas hourly space velocity (GHSV) of 21,000 mLg_cat⁻¹h⁻¹ under the optimized reaction conditions. Temperature-programmed surface reaction (TPSR) studies suggest a mechanism involving CO₂ dissociation into CO. The Ni-loaded SBA-1 catalyst demonstrated remarkable stability over five consecutive 24 h cycles, indicating its promising potential for practical application in sustainable energy production and greenhouse gas mitigation.