Highly dispersed Ni nanoparticles supported by porous Al2O3 rods for catalytic dry reforming of methane

Abstract

Dry reforming of methane (DRM) is one of the most valuable ways to convert carbon dioxide (CO₂) and methane (CH₄) simultaneously. Although Ni-based catalysts have been widely used due to their high activity and low cost, the problems with sintering and carbon deposition have consistently limited their large-scale industrial applications. In this work, based on the high surface area and excellent adsorption capacity of porous Al₂O₃ materials, three kinds of rod-like Ni–Al₂O₃ catalysts (Ni–Al₂O₃-500, Ni–Al₂O₃-700, and Ni–Al₂O₃-900) were successfully synthesized using an impregnation strategy and calcination at 500, 700 and 900 °C, respectively. During the 60 h stability test, the conversions of CH₄ and CO₂ catalyzed by the Ni–Al₂O₃-700 catalyst with 3% Ni were consistently maintained at around 60.0% and 65.0%, respectively, with only 5.8% residual carbon on the catalyst surface. According to the analysis of temperature programmed reduction (H₂-TPR), X-ray photoelectron spectroscopy (XPS), temperature programmed deposition (CO-TPD) and the test results, the influence of calcination temperature on the catalytic performance of the Ni–Al₂O₃ catalyst was comprehensively studied. Under different calcination temperatures, the interaction between Ni species and porous Al₂O₃ support was successfully regulated. Different from introducing more favorable chemical components to the catalyst system, this work created a rod-like Ni–Al₂O₃-700 catalyst with excellent resistance to carbon deposition and sintering and a higher ratio of Ni⁰/Ni²⁺ (0.044) based on the calcination temperature and the changes of microstructure during the phase transition of Al₂O₃ materials, which provided a new strategy for constructing a structured and high-performance Ni-based catalyst.