Dry reforming of methane over embedded Ni nanoparticles in CeZrO2: Effect of Ce/Zr ratio and H2O addition

Abstract

Biogas has emerged as renewable source of CH4 towards energy decarbonization in recent years. Among the biogas valorization routes, the dry reforming of methane (DRM) process is particularly interesting for H2 production. However, the development of new catalysts with high metal dispersion and coke resistance is a significant challenge, particularly under industrial condition. Therefore, this work studies the performance of Ni@CexZr1-xO2 catalysts with different Ce/Zr molar ratios for the dry reforming and bi-reforming of methane reactions. The addition of Zr promotes the Ni dispersion and the oxygen mobility of the support, leading to enhanced resistance to coke formation. Additionally, H2O suppresses coke formation under high CH4/CO2 molar ratio, but catalyst deactivation is still observed. Finally, an optimal Ce/Zr molar ratio (i.e., 4.0) is achieved, demonstrating remarkable resistance to coke formation and high CH4 and CO2 conversion rates through the control of Ni particle size and the promotion of oxygen mobility.