Ni-based Catalysts Supported on SCS–Derived MgAl2O4 for CO2 Methanation: Effect of Bimetallic Promoters

Abstract In this study, Ni-based catalysts (Ni, NiFe, and NiCo) were synthesized via wet impregnation method using MgAl 2 O 4 spinel supports calcined at 700, 800, and 900 °C. These supports, previously synthesized and optimized by the solution combustion method, enabled investigation of thermal treatment and bimetallic promotion affect catalytic performance in CO 2 methanation. Structural, morphological, and redox properties were characterized using XRD, BET, FT-IR, SEM-EDS, TEM, H 2 -TPR, CO 2 -TPD, and TGA analyses. Catalytic activity tests under atmospheric pressure revealed that the NiCo catalyst supported on MgAl 2 O 4 calcined at 800 °C exhibited the highest CO 2 conversion and CH 4 selectivity. This enhancement was attributed to improved metal dispersion, stronger metal–support interaction, and synergistic effects between Ni and Co species. These results demonstrate dual impact of support calcination temperature and bimetallic design on methanation efficiency. This work offers valuable insight into the rational design of thermally stable and highly active Ni-based catalysts for efficient CO 2 utilization in methane production. Graphical Abstract