Microporous　supports　typically　fail　to　fully　expose　active　sites　for　electrolytes　and　CO2　molecules,　and　this　usually　results　in　low　current　density　for　the　electrocatalytic　CO2　reduction　reaction　(CO2RR).　To　overcome　the　biggest　obstacle　and　facilitate　commercial　applications,　defective　single-atomic　Ni-N3　sites　anchored　to　ordered　micro-macroporous　N-doped　carbon　(Ni-N/OMC)　have　been　prepared　by　the　pyrolysis　of　the　Ni-ZIF-8@PS　(ZIF　=　zeolitic　imidazolate　framework)　and　are　intended　to　provide　enhanced　CO2RR　with　a　current　density　at　an　industrial　level.　This　Ni-ZIF-8@PS　is　constructed　of　nickel-based　ZIF-8　embedded　in　the　three-dimensional　(3D)　highly　ordered　polystyrene　spheres　(PS).　The　3D　ordered　micro-macroporous　architecture　of　Ni-N/OMC　could　facilitate　the　mass　transfer　of　substrates　to　the　accessible　defective　single-atomic　Ni-N3　sites　through　micropores　(0.6　nm)　and　macropores　(∼200　nm)　interconnected　by　50　nm　channels.　In　a　flow　cell,　Ni-N/OMC　exhibits　almost　100.0%　CO　Faraday　efficiency　(FECO)　between　−0.2　and　−1.1　V　vs.　RHE　and　an　industrial　level　CO　partial　current　density　of　208　mA　cm−2.　It　has　a　turnover　frequency　of　1.5×105　h−1　at　−1.1　V　vs.　RHE　in　1　M　KOH　electrolyte,　which　exceeds　that　of　most　reported　nickel-based　electrocatalysts.　This　excellent　CO2RR　performance　for　Ni-N/OMC　makes　it　a　state-of-the-art　electrocatalyst　for　CO2RR.　Theoretical　calculations　show　that　the　defective　Ni-N3　site　can　lower　the　energy　of　*COOH　formation　compared　with　that　of　the　Ni-N4　site,　thereby　accelerating　CO2RR.　Ni-N/OMC　can　also　be　utilized　as　a　cathodic　catalyst　in　Zn-CO2　battery,　exhibiting　high　CO　selectivity　in　the　discharge　process　and　excellent　stability.　This　work　paves　a　pathway　to　rational　design　of　highly　efficient　electrocatalysts　with　3D　hierarchically　ordered　micro-macroporous　architecture　for　CO2RR　towards　industrial　production　and　commercial　applications.[Figure　not　available:　see　fulltext.].　©　2022,　Science　China　Press　and　Springer-Verlag　GmbH　Germany,　part　of　Springer　Nature.