Chemical looping-based catalytic CH4 decomposition and successive coke gasification with CO2 on ordered mesoporous NiMCeOx (M = Co, Zr, La)

Abstract

Highly ordered mesoporous NiLaCeOx mixed metal oxides were investigated as effective catalysts for the chemical looping-based dry reforming of methane (CH4) with carbon dioxide (CO2) (CL-DRM). This catalyst exhibited an excellent catalytic activity and stability in the decomposition of CH4 to form H2 with surface carbons subsequently activated by CO2 via reverse Boudouard reaction to form CO. Among the NiMCeOx catalysts with various promoter (M = Co, Zr, or La), the optimal NiLaCeOx catalyst preserved its original highly ordered mesoporous structures, leading to the higher dispersion of smaller Ni nanoparticles. This was attributed to the stronger Ni-Ce interactions facilitated by the La2O3 metal oxide promoter. The NiLaCeOx demonstrated a higher rate of H2 formation and successive CO production in the CL-DRM reaction, resulting in a H2/CO ratio above 1.0. Additionally, the NiLaCeOx catalyst exhibited superior structural stability over 5 cyclic CL-DRM reactions for CH4 decomposition (>85 %) and CO2 activation (>45 %), with minimal deposition of cokes.