Enhanced CO2Methanation Reaction in C1 Chemistry over a Highly Dispersed Nickel Nanocatalyst Prepared Using the One-Step Melt-Infiltration Method

The Paris Agreement requires the world to put the best efforts to reduce CO(2)emissions, due to the global warming problems. As a promising technology corresponding to this greenhouse gas treatment, the CO(2)methanation process a.k.a power to gas (PtoG), which catalytically converts CO(2)into methane, has been in the limelight. To develop an efficient catalytic process, it is necessary to design a low-cost and high-efficiency catalyst for high CO(2)conversion and CH(4)selectivity. In this study, we have developed Ni/gamma-Al(2)O(3)catalysts by the one-step melt-infiltration method, where both aging and calcination are done in one pot. For enhancement of the catalytic activity and selectivity, sufficient Ni content (>25 wt %) and a high dispersion (<10 nm) are simultaneously required. Thus, the aging conditions of the melt-infiltration methods, e.g., time and temperature, were optimized for the high dispersion with sufficient Ni content (15-50 wt %). The catalytic performance tests were carried out under atmospheric pressure, 275 to 400 degrees C and gas hourly velocity (GHSV) = 25,000 h(-1). And the various characteristic analyses (Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), H-2-chemisorption, temperature programmed reduction (TPR), etc.) were performed to confirm the effects on the catalytic performance. As a result, based on the experiments and the characterization data, the 30 wt %-Ni catalyst (Ni particles size = 11 nm) showed the best CO(2)conversion at 300 degrees C and the 20 wt % one having the highest Ni dispersion (Ni particles size = 8.8 nm), which showed the best intrinsic reaction rate and CH(4)selectivity in the entire temperature range.