Two-electron　oxygen　reduction　reaction　(2e−　ORR)　for　H2O2　production　is　regarded　as　a　more　ecologically　friendly　substitute　to　the　anthraquinone　method.　However,　the　search　of　selective　and　cheap　catalysts　is　still　challenging.　Herein,　we　developed　a　neutral-selective　and　efficient　nonprecious　electrocatalyst　that　was　prepared　from　a　commercial　activated　carbon　(AC)　by　simply　microwave-assisted　ash　impurity　elimination　and　hydrogen　peroxide　oxidation　for　surface　functional　sites　optimization.　The　oxygen　configuration　can　be　tuned　with　enriching　carboxyl　group　up　to　6.65　at.%　by　the　dosage　of　hydrogen　peroxide　(mass　ratio　of　H2O2/C　=　∼0-8.3).　Chemical　titration　experiments　identified　the　carbonyl　groups　as　the　most　potential　active　sites,　with　selectivity　boosted　by　the　additional　carboxyl　groups.　The　microwave-assisted　moderate-oxidized　activated　carbon　(MW-AC5.0)　demonstrated　optimal　2e−　ORR　activity　and　selectivity　in　neutral　electrolyte　(0.1　M　K2SO4),　with　H2O2　selectivity　reaching　∼75%-97%,　a　maximum　H2O2　production　rate　(1.90　mol·gcatal−1·h−1@0.1　V)　and　satisfying　faradaic　efficiency　(∼85%)　in　gas-diffusion-electrode.　When　coupled　with　Fenton　reaction,　it　can　degrade　a　model　organic　pollutant　(methylene　blue　[MB],　50　ppm)　to　colorless　in　a　short　time　of　20　min,　indicating　the　potential　applications　in　the　environmental　remediation.　©　2023　IOP　Publishing　Ltd