Ni/MgAl2O4 catalyst for low-temperature oxidative dry methane reforming with CO2

Oxidative dry reforming of methane has been performed for 100 h on stream using Ni supported on MgAl2O4 spinel at different loadings at 500-700 degrees C, CO2/CH4 molar ratio of 0.76, and variable O-2/CH4 molar ratio (0.12-0.47). Syngas with an H-2/CO ratio of 1.5-2.1 has been produced by manipulating reforming feed composition and temperature. The developed oxidative dry reforming process allowed high CH 4 conversion at all conditions, while CO2 conversion decreased significantly with the lowering of the reforming temperature and increasing O-2 concentration. When considering both greenhouse gas conversions and O-2/CO ratio enhancement, the optimal reforming condition should be assigned to 550 degrees C and O-2/CH4 molar ratio of 0.47, which delivered syngas with H-2/CO ratio of 1.5. Coke-free operation was also achieved, due to the combustion of surface carbon species by oxygen. The 3.4 wt% Ni/MgAl2O4 catalyst with a mean Ni nanoparticle diameter of 9.8 rim showed stable performance during oxidative dry reforming for 100 h on stream without deactivation by sintering or coke deposition. The superior activity and stability of MgAl2O4 supported Ni catalyst shown during reaction trials is consistent with characterization results from XRD, TPR, STEM, HR-STEM, XPS, and CHNS analysis. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.