Insight into the effects of the CO2/H2O activation and Ce redox cycle over ni/CeO2/hydrotalcite catalyst surface on biogas Bi-reforming for methanol friendly syngas

The use of green biogas as a raw material for producing methanol-friendly syngas (H2/CO ≈ 2) for one-step methanol synthesis has gained significant attention. However, developing efficient catalysts with high activity and stability remains challenging, as they often face issues with stability and carbon deposition. This study presents a Ni/CeO2/HT catalyst designed for high activity and long-term stability by leveraging the Ce redox cycle and strong interactions between Ni-CeO2 and hydrotalcite (HT). The catalyst benefits from abundant oxygen vacancies generated by the Ce3+ - Ce4+ pathway, enhancing its ability to activate CO2 and H2O and providing excellent coke resistance. Comprehensive analyses of CO2/H2O adsorption and carbon elimination mechanisms were conducted using techniques such as in situ H2-TPR, CO2/H2O-TPSR, in situ CH4-TPSR, CO2/H2O-TPO, and FTIR. The Ni/CeO2/HT catalyst outperformed others in CO2/H2O adsorption and CH4 activation capacity, promoting the generation of active oxygen species and effectively removing coke precursors, thereby improving resistance to Ni sintering and carbon deposition. At 750 °C and a weight hourly space velocity (WHSV) of 32,400 mLgCat−1 h−1, it achieved CH4 and CO2 conversions of 93 % and 66 %, respectively, with long-term stability exceeding 200 h.