CO2 methanation over BEA zeolite catalysts: Effect of MgO and in-situ Ni incorporation

Carbon dioxide methanation is a promising carbon management technology that reduces CO 2 concentrations and facilitates the long-term storage of excess renewable energy, thereby closing the carbon cycle. This study investigates the catalytic performance of BEA zeolite-based catalysts in the methanation of CO 2 , focusing on the role of MgO as a promoter and investigating the incorporation of Ni by in-situ method. The catalysts were synthesized via two methods: post-modification with Ni and MgO loading, and in-situ incorporation of Ni within the zeolite framework. Characterization techniques, including X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), H 2 -TPR, and CO 2 -TPD, were used to evaluate the physical and chemical properties of the catalysts. The results demonstrated that MgO promoted the catalytic activity of BEA zeolites, enhancing CO 2 conversion and methane selectivity at lower reaction temperatures. The in-situ incorporation of Ni showed negligible activity at temperatures below 350 °C but outperformed post-modified catalysts at higher temperatures, particularly above 400 °C. These findings suggest that while post-modified catalysts are more effective at lower temperatures, in-situ Ni incorporation offers superior catalytic performance at elevated temperatures, making it a promising approach for high-temperature methanation reactions. This work contributes to the development of efficient catalysts for CO 2 methanation, supporting carbon capture and utilization efforts. Beta (BEA) zeolite structure modified by post and in-situ methods. The in-situ method incorporated Ni into BEA zeolite structure by replacing silicon or aluminum atoms, while the post-modification method disperses NiO on both the surface and within the pores of the BEA zeolite structure • BEA zeolite synthesized, modified with MgO, and 13 wt% Ni via post-modification. • MgO in BEA catalysts boosts CO 2 conversion and methane selectivity. • 5 wt% MgO and 13 wt% Ni catalyst showed optimal performance and over 50 h stability. • Ni incorporated successfully into the BEA zeolite framework using in-situ method. • In-situ Ni method achieved 6.6 h −1 TOF vs. 14 h −1 for post-modification.