The　low-potential　formaldehyde　oxidation　reaction　(FOR)　is　a　significant　replacement　for　oxygen　evolution　reaction,　as　FOR　can　couple　with　the　cathode　hydrogen　evolution　reaction　(HER)　to　obtain　a　bipolar　H2　production　system　with　an　extra　low　cell　voltage.　Cu-based　electrocatalysts　offer　cost　advantages　in　FOR　but　suffer　from　poor　intrinsic　activity　and　stability.　Herein,　a　novel　defect　rich　CF-Cu@Cu2+1O/Cu　pinecone-shaped　array　electrocatalyst　is　fabricated　by　in-situ　solution　immersion　of　electrodeposited　Cu　cone　arrays　on　foam　for　efficient　and　stable　formaldehyde　selective　oxidation　reaction　to　co-produce　hydrogen　and　valuable　formate.　Benefitting　from　the　partially　mixed　Cu2+1O　in　metallic　copper　and　concomitant　production　of　defect　rich　oxygen　vacancies,　only　0.04　VRHE　is　required　for　electrocatalytic　FOR　at　100　mA·cm−2　under　alkaline　conditions.　FOR　current　density　of　CF-Cu@Cu2+1O/Cu　electrode　exhibits　2.35　times　than　that　of　CF-Cu　(144　mA·cm−2)　and　77　times　than　that　of　copper　foam　(4.4　mA·cm−2)　at　0.5　VRHE.　Moreover,　the　special　pinecone-shaped　structure　is　constructed　to　modify　Cu-based　catalysts　with　substantially　enhanced　stability.　A　FOR-HER　co-electrolysis　device　of　CF-Cu@Cu2+1O/Cu(+)||Pt/C(−)　can　achieve　bipolar　H2　production　with　an　approaching　200　%　Faradaic　efficiency,　requiring　an　extremely　low　electrical　energy　consumption　of　only　∼　0.35　kWh　per　m3　of　H2　and　potential　of　0.291　V　at　100　mA·cm−2　at　room　temperature.　©　2024　Elsevier　B.V.