Although the renewable energy will play a major role in the energy supply in the future. its unavoidable fluctuation in the energy supply requires the energy storage system. To store the surplus energy from the renewable energy sector, the power-to-gas concept was proposed to convert CO2 into methane with hydrogen produced using the surplus electricity. Methane can be used directly for the generation of heat and electricity, or it can be distributed through developed infrastructure. The CO2 methanation, which is called Sabatier reaction, was first reported in the early 1900s. Nickel is reported to be active and selective towards methane production. Since this is an exothermic reaction, it is desirable to develop the catalyst active at low temperatures to achieve high single-pass conversion of CO2. Additionally, the facilitated heat removal is also important not to form the hot spots in the catalyst bed. The core-shell structure has gained much interest in catalysis because the multi-purpose design of catalyst can be done by changing the composition of core and shell. The unique core-shell Al@Al2O3, which can be obtained by a simple hydrothermal surface oxidation (HTSO) of Al metal particles in an aqueous solution of heterometal ions at elevated temperature (150 oC), is used as the support for Ni catalysts for CO2 methanation. The catalytic activity was measured at atmospheric pressure in the reaction temperature range 140 - 450 oC. The feed gas composed of 1 mol% CO (or CO2), 50 mol% H2, and 49 mol% He was contacted with 0.10 g of the catalyst at a flow rate of 100 mL/min. Various techniques including N2 physisorption, CO2, H2 chemisorption, H2-TPR, chemisorption, CO2-TPD, XRD, ICP-OES, STEM-EDX, and TEM are employed to characterize the catalysts. The use of the core-shell micro-structured support Al@Al2O3 is very helpful to develop the highly efficient Ni-based catalyst at low reaction temperatures compared to commercial γ-Al2O3 on CO2 methanation. Besides, the deposition-precipitation method has a significant effect on the catalytic performance compared with the wet-impregnation due to the improvement of the dispersion of NiO nanoparticles as well as the increased fraction of the reduced active Ni species. Enhanced resistance to Ni sintering is also observed over Ni/Al@Al2O3.

CO2 methanation over Ni/Al@Al2O3 core-shell catalyst

2019 Spring National Meeting

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