Ni/CeO2 catalysts incorporated with cassava-peel-derived biochar for CO2 methanation: Effects of biochar activation and impregnation route

Abstract

Modifying highly active Ni/CeO 2 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/CeO 2 -based catalyst for methanation. The as-prepared catalysts were tested for CO 2 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/CeO 2 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/CeO 2 catalysts with high catalytic activity corresponding to a CO 2 conversion of 74.8% and a CH 4 selectivity of over 98% at 350 °C. This high catalytic activity remained stable without any significant deactivation throughout a 100-hour 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.