In　the　quest　for　long-lasting　energy　alternatives,　solid　oxide　electrolysers　have　become　a　crucial　technology　in　facilitating　the　transformation　of　CO2　toward　fuels　and　valuable　chemicals.　This　study　proposes　a　unique　method　for　the　catalytic　reduction　of　carbon　dioxide　at　the　cathode　using　porous　CeO2　single-crystal　electrodes　in　a　solid　oxide　electrolyser,　utilizing　temperatures　from　an　industrial　waste　heat　stream.　The　fluxes　and　chemical　states　of　oxygen-containing　species　evolved　from　the　cathode　were　identified　and　designed,　and　the　catalytic　process　of　CO2　reduction　to　CO　was　effectively　regulated　by　the　oxygen-containing　species　(lattice　oxygen,　oxygen　vacancies　and　adsorbed　oxygen).　The　results　show　that　the　CO　yield　can　reach　6.05　mL　min−1　cm−1　with　porous　(111)　CeO2　single　crystal　as　the　cathode　at　850　°C　and　1.8　V.　The　solid　oxide　electrolyser　exhibits　remarkable　stability　even　after　100　h　of　continuous　operation.　©　2024　Elsevier　B.V.