High-performance Ni–Ce1−xZrxO2 nanoparticles for biogas reforming: enhanced CO2 activation and stability

Abstract

The efficient utilization of renewable biogas has attracted ever-increasing interest in the past few decades. Ni–Ce_1−xZr_xO₂ supported on monolithic SiC-F (named Ni–Ce_1−xZr_xO₂/SiC-F) is developed and applied in biogas reforming. Monolithic Ni–Ce_1−xZr_xO₂/SiC-F catalysts were comprehensively characterized by ICP-AES, XRD, SEM, HR-TEM, CO₂-TPD, etc. The promotional roles of Ce_1−xZr_xO₂ in coke elimination as well as CO₂ activation were deeply analyzed via in situ CH₄-TPSR/CO₂-TPO and in situ H₂-TPR/CO₂-TPSR. Ni–Ce_1−xZr_xO₂/SiC-F exhibits satisfactory catalytic activity and ability to inhibit sintering and coke-deposition due to (a) the homogeneous dispersion of Ni nanoparticles (NPs) and (b) the strong interaction between Ce_1−xZr_xO₂ solid solutions and Ni NPs. At 900 °C and a weight hourly space velocity (WHSV) of 24 000 mL g_cat⁻¹ h⁻¹, an excellent CH₄/CO₂ conversion of 90/92% was initially achieved over the Ni–Ce_1−xZr_xO₂/SiC-F catalyst, followed by a slight decrease after 150 h, but remained basically stable for the next 250 h.