Structured NiFe catalysts derived from in-situ grown layered double hydroxides on ceramic monolith for CO2 methanation

Monolithic catalysts for CO2 methanation have become an active research area for the industrial development of Power-to-Gas technology. In this study, we developed a facile and reproducible synthesis strategy for the preparation of structured NiFe catalysts on washcoated cordierite monoliths for CO2 methanation. The NiFe catalysts were derived from in-situ grown layered double hydroxides (LDHs) via urea hydrolysis. The influence of different washcoat materials, i.e., alumina and silica colloidal suspensions on the formation of LDHs layer was investigated, together with the impact of total metal concentration. NiFe LDHs were precipitated on the exterior surface of cordierite washcoated with alumina, while it was found to deposit further inside the channel wall of monolith washcoated with silica due to different intrinsic properties of the colloidal solutions. On the other hand, the thickness of in-situ grown LDHs layers and the catalyst loading could be increased by high metal concentration. The best monolithic catalyst (COR-AluCC-0.5M) was robust, having a thin and well-adhered catalytic layer on the cordierite substrate. As a result, high methane yield was obtained from CO2 methanation at high flow rate on this structured NiFe catalysts. The monolithic catalysts appeared as promising structured catalysts for the development of industrial methanation reactor.