Chromate cathode decorated with in-situ growth of copper nanocatalyst for high temperature carbon dioxide electrolysis

Composite cathode based on La0.75Sr0.25Cr0.5Mn0.5O3−δ (LSCM) can be used for direct carbon dioxide electrolysis without a flow of reducing gas over it in an oxide-ion-conducting solid oxide electrolyzer; however, the insufficient electro-catalytic activity of LSCM electrode still restricts electrode performance and Faraday current efficiency. In this work, catalytic-active copper nanoparticles are grown on the surface of LSCM cathode via in-situ exsolution of copper metal from A-site deficient and B-site excess (La0.75Sr0.25)0.9(Cr0.5Mn0.5)0.9Cu0.1O3−δ (LSCMC) after reduction. XRD, SEM, EDS and XPS results together confirm the reversible exsolution of copper nanocatalyst on the surface of LSCM. Carbon dioxide adsorption/desorption of LSCM is investigated. The electrical properties of reduced LSCMC are investigated and correlated to the electrochemical performance of the composite electrodes. The current efficiencies of approximately 85% are obtained with LSCM cathode decorated with copper nanocatalyst for direct carbon dioxide electrolysis in an oxide-ion-conducting solid oxide electrolyzer.