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%0 Thesis
%A Ren, Jie
%T Designing highly active and stable Ni-based catalysts for methanation of carbon dioxide
%I RWTH Aachen University
%V Dissertation
%C Aachen
%M RWTH-2022-03376
%P 1 Online-Ressource : Illustrationen
%D 2022
%Z Veröffentlicht auf dem Publikationsserver der RWTH Aachen University
%Z Dissertation, RWTH Aachen University, 2022
%X Power-to-Gas (PtG) concept is under discussion as a technology for storing energy on a large scale as a result of the fluctuating and locally concentrated availability of renewable energy sources. Therefore, methanation of CO2 with renewable H2 (i.e., via electrolysis) is considered promising due to the fact that it can be integrated in the existing infrastructure of natural gas and electricity grids. CO2 methanation is an exothermic and thermodynamically favorable reaction requiring an effective catalyst. Ni-based catalysts are widely investigated for CO2 methanation due to their low cost, easy availability, and comparable activity during the reaction. Nevertheless, conventional Ni-based catalysts (i.e., Ni/Al2O3) are easily deactivated due to sintering and coke deposition during the exothermic methanation reaction. Hence, Ni-based catalysts with enhanced properties (e.g., special structure, Ni dispersion, oxygen vacancy, reduction degree) need to be deeply investigated for providing crucial knowledge for related researchers. In chapter 2, hydrotalcite-derived Mg-Al oxides with different morphologies were synthesized through co-precipitation and used for Ni-based catalyst preparation. The effect of support morphology on the Ni dispersion and catalytic activity in CO2 methanation was investigated. Obtained supports and catalysts were rigorously characterized by various techniques, determining crystallite size, Ni dispersion, morphologies, and basic sites of the materials. The activity, selectivity, and long-term stability of Ni-based hydrotalcite-derived catalysts were evaluated for CO2 methanation under different conditions (i.e., gas hourly space velocities, reaction temperatures, and reduction temperatures). Based on the results, Mg-Al hydrotalcites prepared under solution pH of 10 and aging temperature of 20 oC (MAH-10) supported 20 wt
%F PUB:(DE-HGF)11
%9 Dissertation / PhD Thesis
%R 10.18154/RWTH-2022-03376
%U https://publications.rwth-aachen.de/record/843754