Ni/CeO2 Catalysts Incorporated with Cassava-Peel-derived Biochar for CO2 Methanation: Effects of Biochar Activation and Impregnation Route

Modifying highly active Ni/CeO2 catalysts with less expensive materials whilst maintaining their catalytic activity is a challenging yet intriguing research direction. Herein, biochar was engineered from cassava peels and introduced into a Ni/CeO2-based catalyst for methanation. The as-prepared catalysts were tested for CO2 methanation in a temperature range of 250 °C – 400 °C at a volumetric weight hourly space velocity of 30,000 mL g−1 h−1. Systematic analysis of the prepared materials was conducted to elucidate the performance–characterisation relationship. The incorporation of biochar resulted in modified Ni/CeO2 catalysts with favourable textural properties and Ni crystallite sizes (25–37 nm). Sequential impregnation was found to be an effective procedure to fabricate biochar-modified Ni/CeO2 catalysts with high catalytic activity corresponding to a CO2 conversion of 74.8% and a CH4 selectivity of over 98% at 350 °C. This high catalytic activity remained stable without any significant deactivation throughout a 100-h stability test. Although further development is still needed, the obtained results show the potential of utilising low-value biomass resources to tailor a high-performance catalyst with good catalytic activity and stability during methanation.