Solid　oxide　electrolysis　cells　(SOECs)　can　convert　the　electric　energy　into　chemical　energy,　which　is　convenient　for　energy　storage　and　transportation.　Meanwhile,　it　can　reduce　the　CO2　and　CH4　in　the　atmosphere,　thus　reduce　the　greenhouse　effect.　In　this　paper,　we　demonstrate　the　high-efficiency　electrochemical　reforming　of　CO2/CH4　into　syngas　(CO　and　H2)　in　a　SOEC　in　which　we　in　situ　construct　active　metal-oxide　interface　in　perovskite　cathodes　to　improve　the　coking　resistance　and　catalyst　stability.　XRD,　XPS,　SEM　and　TEM　analysis　together　confirm　that　the　exsolution　of　metal-oxide　interfaces　on　the　surface　of　LSCM　creates　the　active　electrochemical　interface　to　enhance　the　activity　as　well　as　the　stability　with　the　durable　operation　of　CO2　and　CH4　to　syngas　for　more　than　70　h　and　7　redox　cycles.　The　exsolved　metal-oxide　interface　could　also　be　applied　for　other　metal-oxide　catalyst　for　improving　catalytic　activity　and　stability.　©　2022　Elsevier　B.V.