Modification of the Microstructure and Transport Properties of La2CuO4−δ Electrodes via Halogenation Routes

Abstract

Ruddlesden–Popper type electrodes with composition La2CuO4−δ are alternative cathode materials for solid oxide fuel cells (SOFCs); however, the undoped compound exhibits low electrical conductivity for potential applications, which is usually increased by alkaline-earth doping. A promising alternative to alkaline-earth doping is the modification of the anionic framework by halogen doping. In this study, La2CuO4−0.5xAx (A = F, Cl, Br; x = 0–0.3) compounds are prepared by a freeze-drying precursor method, using an anion doping strategy. The composition, structure, morphology and electrical properties are studied to evaluate their potential use in solid oxide fuel cells (SOFCs). The halogen-doped materials show higher electrical conductivity and improved electrocatalytic activity for oxygen reduction reactions when compared to the pristine material, with polarization resistance values 2.5 times lower, i.e., 0.20, 0.11 and 0.08 Ω cm2 for undoped, F- and Cl-doped samples, respectively, at 800 °C. Moreover, halogen doping prevents superficial copper segregation in La2CuO4−δ, making it an attractive strategy for the development of highly efficient electrodes for SOFCs.

Halide ions doped SrMnO3 for chemical looping oxidative dehydrogenation of ethane

“…This difference can be attributed to the larger radius of Sc 3+ compared to Fe 3+ (with Sc 3+ 0.81 Å > Fe 3+ 0.64 Å). The Rietveld refinement was used to further analyze the lattice structures of redox catalysts, and the refined results were summarized in Table 1 31,32 . The Rietveld refinement plots for SMO, SMOC, and SMOB were shown in Fig.…”

“…The Rietveld refinement was used to further analyze the lattice structures of redox catalysts, and the refined results were summarized in Table 1. 31,32 The Rietveld refinement plots for SMO, SMOC, and SMOB were shown in Fig. 6(A-C).…”