CO2 methanation over open cell foams prepared via chemical conversion coating

Abstract

In the framework of the CO2 utilization, and of the integration of renewable energy sources into the power generation scenario, the methanation reaction plays a key role, being the core of the power-to-gas, or power-to-X, processes. Structured catalysts are widely recognized for being particularly promising in exothermic processes, as they ensure a better thermal management of the heat generated within the system. In recent years, the application of metallic structures has spread. Nevertheless, the functionalization of these structures via washcoating procedure has several disadvantages. Herein, it is highlighted the potential of ceria chemical-conversion coating (CCC) as technique for the preparation of methanation catalysts, and optimize the Ni deposition procedure on such structures. In this work, the suitability of the obtained catalysts for CO2 methanation was evaluated in several operating conditions, obtaining CO2 conversion as high as 70 % below 400 °C with the most promising sample. In a first analysis, it was demonstrated that the catalysts prepared through the CCC technique can be applied in the CO2 methanation systems. In addition, through a kinetic analysis it was highlighted that the preparation method could be a key parameter for the selectivity of the process, driving the system towards a direct CO2 methanation or to the CO-path mechanism, therefore further studies should be performed to better explore this aspect.