Demonstration of direct conversion of CO₂/H₂O into syngas in a symmetrical proton-conducting solid oxide electrolyzer

We have previously reported the electrochemical reduction of CO₂ to CO with simultaneous steam electrolysis in a proton conducting solid oxide electrolyzer (PCSOE); however, the conventional Ni-cermet electrode is rapidly oxidized by H₂O/CO₂ in cathode that causes cell performance degradation. In this work, we report a novel symmetrical PCSOE with redox-stable LSCM ((La_0.75Sr_0.25)_0.95Cr_0.5Mn_0.5O_3-δ) electrode for the electrochemical conversion of CO₂/H₂O into syngas (CO/H₂). The Ru catalyst is impregnated to LSCM to improve electrode activity. Electrochemical measurements demonstrate that the CO₂ is electrochemically reduced to syngas (CO/H₂) with simultaneous steam electrolysis. The loading of Ru catalyst promotes the electrochemical process with higher Faradic efficiency while induces a more competitive process of hydrogen evolution at 700 °C.