RuNi-Supported TiO2-Modified MgAl2O4 Catalyst for CO Selective Methanation in Hydrogen-Rich Gas

CO selective methanation is regarded as an efficient technological solution for hydrogen-rich gas purification in fuel cells. In this study, a series of bimetallic catalysts (Ru-Ni/xTiO2-MgAl2O4) were synthesized by impregnation method after surface modification of MgAl2O4 supports with different contents of TiO2. The prepared catalysts were characterized by XRD, BET, SEM, TEM, H2-TPR, CO-TPD, NH3-TPD, and XPS. The Ru-Ni/10TiO2-MgAl2O4 exhibited excellent CO-SMET performance, removing the CO in the H2-rich gas to less than 10 ppm with the selectivity above 50% in a temperature window range of 210–280 °C. The results showed that the TiO2-modified MgAl2O4 support not only improved the interaction between metal and support, and promoted the dispersion of active component nanoparticles on the support, but also introduced oxygen vacancies or defects in the catalyst and enhanced the acidity, resulting in better catalytic activity and stability.