The　precise　control　of　morphology　and　structure　of　porous　carbon　derived　from　metal-organic　frame-works　(MOFs)　is　crucial　for　determining　the　oxygen　reduction　reaction　(ORR)　activity.　Herein,　defect-enriched　hollow　porous　Co-N-doped　carbon　nanomaterials　(Co-N/PCNs)　towards　ORR　were　obtained　by　pyrolyzing　a　ZIF-8　encapsulated　Co　ions　nanocomposite.　We　found　that　the　amount　of　the　incorpo-ration　of　cobalt　(II)　into　ZIF-8　precursors　play　very　important　role　in　the　structural　evolution　of　ZIF-8　derivatives　during　the　high　temperature　pyrolysis.　The　experiments　show　that　defect-enriched　hollow　porous　Co-N-doped　carbon　derived　from　the　incorporation　of　2　wt%　cobalt　(II)　into　ZIF-8　precursors　(Co-N/PCNs-2)　showed　excellent　stability　and　activity　towards　ORR.　The　onset　potential　(E-onset)　and　the　half-wave　potential　(E-1/2)　on　Co-N/PCNs-2　are　0.99　V　and　0.88　V,　respectively,　outperforming　the　commercial　Pt/C　(E-onset　=　0.98　V,　E-1/2　=　0.85　V).　Moreover,　the　Zn-air　batteries　with　Co-N/PCNs-2　as　an　air　electrode　displays　robust　stability　and　high　activity,　affording　a　maximum　power　density　of　135　mW　cm(-2)　in　comparison　with　the　Pt/C　catalysts　(114　mW　cm(2)).　The　density　functional　theory　(DFT)　verified　that　the　Co-N-X　active　site　along　with　the　defects　are　conducive　to　the　O-2　adsorption　and　thus　improve　the　ORR　process　compared　with　the　pure　Co-N-X　active　site.　(C)　2020　Elsevier　Ltd.　All　rights　reserved.