Preparation of methanation catalysts for high temperature SOEC by β-cyclodextrin-assisted impregnation of nano-CeO2 with transition metal oxides

The aim of this work was to prepare and examine the catalytic activity of nanometric CeO2 decorated with transition metal oxides Ni, Co, Cu, Fe and Mn towards a high temperature methanation process under SOEC CO2/H2O simulated co-electrolysis conditions. Samples were prepared using the wet impregnation method via the conventional process and with the addition of native cyclodextrin. The influence of beta-cyclodextrin (beta CD) onto the size, dispersion and integration of the obtained metal nanoparticles was investigated. The differences between the catalysts' reducibility revealed that samples prepared from beta CD-containing solutions, in most cases, resulted in the creation of smaller MexOy NPs on the surface of the substrate material compared to those prepared using traditional nitrate solutions. The samples containing Ni and Co were the only ones that observably catalysed methane synthesis. The high dispersion and integration of NPs prepared via the proposed synthesis route resulted in increased catalytic activity and enhanced stability, which was most pronounced for the Co-impregnated sample. The methane production peak for Ni-beta CD/CeO2 at 375 degrees C was characterised by nearly 99% CO conversion and 80% selectivity towards CH4 production. Co-beta CD/CeO2 reached 84% CO conversion and almost 60% methane selectivity at 450 degrees C. The usage of CeO2 coupled with beta CD for the preparation of catalysts for high-temperature methane synthesis for use in SOECs gave promising results for further application. (C) 2021 The Author(s). Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC.

Automated summary

The study focused on preparing and investigating the catalytic activity of nanometric CeO2 decorated with transition metal oxides under high temperature methanation process conditions. The use of beta-cyclodextrin in the synthesis process led to smaller metal nanoparticles with higher dispersion and integration, resulting in enhanced catalytic activity and stability. Ni and Co-containing samples showed the most significant catalytic effects in methane synthesis.