Novel Ce-modified cobalt catalysts supported over α-Al2O3 open cell foams for lean methane oxidation

[EN] A series of CeO2-modified Co3O4 catalysts supported over alpha-Al2O3 foams was prepared by solution combustion synthesis and examined for the lean methane oxidation. Two different fuels were used namely, urea and glycine, with varying fuel/oxidiser (phi) ratio. The catalysts were characterised by SEM-EDX, STEM-HAADF coupled to EDX mapping, ICP-AES, WDXRF, N-2 physisorption, XRD, HRTEM, Raman spectroscopy, XPS, H-2-TPR and CH4-TPRe, and their activity in the abatement of methane was analysed under realistic conditions. The use of glycine produced catalysts with significantly better morphological and structural properties. Likewise, a favoured insertion of cerium cations into the Co3O4 spinel lattice was observed, which caused a significant distortion of the spinel structure, thereby leading to a higher amount of mobile oxygen species capable of oxidising methane. These beneficial structural alterations were more pronounced with higher phi ratios.This work was supported by the Spanish Ministry of Science and Innovation [PID2019-107105RB-I00 AEI/FEDER, UE]; the Basque Government [IT1297-19]; and the University of the Basque Country UPV/EHU [PIF15/335 and DOCREC21/23]. The technical and human support provided by Advanced Research Facilities-SGIker (UPV/EHU), and Central Scientific and Technological Research Services/Atomic Spectroscopy Division (University of Cadiz) is acknowledged. In addition, authors acknowledge the use of instrumentation as well as the technical advice provided by the National Facility ELECMI ICTS, node 'Advanced Microscopy Laboratory' at University of Zaragoza