The　oxidative　dehydrogenation　(ODH)　of　alkane　is　one　of　the　most　attractive　routes　in　alkane　production　because　of　its　favourable　thermodynamic　characteristic.　Nitrogen-doped　nanocarbons　have　demonstrated　great　potential　in　this　reaction　due　to　its　cost-effective,　high　catalytic　activity　and　stability.　However,　the　influence　of　nitrogen　on　the　catalytic　properties　of　carbon　materials　is　poorly　understood　due　to　the　complexities　of　surface　oxygen　and　nitrogen　functional　groups.　Here　we　derive　the　performance　descriptor　that　account　for　the　nitrogen-dependent　carbocatalysis　in　ODH　reaction.　To　achieve　this,　we　designed　a　set　of　nitrogen-doped　nanocarbon　materials　with　tunable　nitrogen　species　by　hydrothermal　carbonization　(HTC)　treatment　of　the　biomass　folic　acid　(FA),　which　are　applied　in　ODH　of　ethylbenzene.　Among　them,　FA-180-1000　catalyst　can　achieve　high　ethylbenzene　conversion　(up　to　-62　%)　and　styrene　selectivity　(-87　%),　outperforming　other　HTC　carbon-based　catalysts.　Structural　characterizations　and　kinetic　analyses　revealed　that　nitrogen　doping　strongly　interferes　the　charge　polarization　of　-C=O　site　via　electron　transfer　between　-C=O,　and　nitrogen　(mainly　pyridine　nitrogen　and　graphitic　nitrogen)　thus　enhancing　the　reactivity　of　-C=O.　Furthermore,　the　induction　period　during　reaction　process　can　be　shortened　by　applying　of　sulfuric　acid-assisted　HTC　method　for　constructing　nitrogen-doped　carbon　catalyst　with　low　crystallinity.　The　present　work　provides　new　insights　into　the　contribution　of　nitrogen　doping　to　the　ODH　reaction　of　carbon　nanocatalysts,　as　well　as　guidance　for　the　rational　design　of　carbon　catalysts　for　the　conversion　of　hydrocarbons　to　high-value　chemicals.　(c)　2023　Elsevier　Inc.　All　rights　reserved.