Optimal Co doping to Ni-based catalyst to promote partial oxidation of methane for syngas production

In this study, Co doped Ni-based catalyst were synthesized and employed for partial oxidation of methane for syngas production. Ni Co bimetallic nanocatalyst displayed excellent catalytic performance at a temperature of 350 to 600 °C in fix-bed reactor. An optimal Co doping level (0.5 M Co precursor) with Ni, significantly favors low temperature (350 °C) partial oxidation of methane to H 2 and CO, while higher Co doping (≥0.7 M Co precursor) resulted in reduced catalytic activity, and reaction shifted toward complete oxidation to CO 2 . A 100-h long-term stability test of optimally Co-doped Ni-based catalyst (Ni 1.2 Mg 0.5 Al 0.5 Co 0.5 ) at 400 °C demonstrated excellent catalytic activity, achieving 90% CH 4 conversion, 78% H 2 and 57% CO selectivities and an H 2 /CO ratio of 1.4 without any notable deactivation. Spent catalysts analysis revealed the formation of metallic Ni ° and Co ° particles with no evidence of coke deposition and negligible sintering during extended reaction periods. The strong catalytic performance is attributed to the formation of metallic Ni ° and Co ° particles, and Ni Co alloy formation through synergistic interaction between Ni and Co that improves redox behavior and stability. The incorporation of Co into Ni-based catalysts induces structural distortions, leading to the formation of surface-active oxygen species (Ni-O/Co-O) and improved lattice oxygen mobility. The superior catalytic performance of Co doped Ni-based catalysts suggest that an optimal Co doping level improves the reaction efficiency by mitigating the coking and sintering issues.