The　borocarbonitrides　(BCNs)　have　exhibited　enormous　potential　as　non-metallic　catalysts　for　alkane　oxidative　dehydrogenation　(ODH)　reactions.　However,　the　poor　electron　transportation　ability　in　BCN　leads　to　a　low　reactivity　of　oxygen　functional　groups　(–C[dbnd]O　and　–B–OH).　Herein,　we　present　a　generalized　strategy　to　promote　the　catalytic　activity　of　BCN　through　in　situ　encapsulation　of　transition-metal　(Fe,　Co,　Ni)　nanoparticles　within　BCN　nanotubes　(BCNNTs).　Among　them,　individual　metal　particles　themselves　do　not　contribute　directly　on　ODH　reactions　and　mainly　serve　as　electron　modulators　to　tune　the　electron　density　of　–C[dbnd]O　and　–B–OH　active　sites　on　BCNNTs.　As　a　result,　catalytic　activities　of　all　metal@BCNNTs　catalysts　surpass　pure　BCN　in　ethylbenzene　(EB)　ODH　reactions,　among　which　Fe@BCNNTs　displays　a　significant　activity　enhancement　with　36　%　EB　conversion　with　the　styrene　(ST)　selectivity　remaining　＞98%　under　gentle　reaction　conditions.　Structural　and　kinetic　analyses　proved　that　the　promotion　effect　originated　from　the　strong　interactions　between　metal　nanoparticles　and　BCNNTs.　The　theoretical　calculations　disclosed　that　the　enhanced　ODH　activity　was　due　to　the　electron　transfer　from　the　encapsulated　metal　to　BCNNTs,　which　increases　the　electron　transportation　ability　and　electron　density　of　BCNNTs,　thus　promoting　the　nucleophilicity　of　–C[dbnd]O　and　–B–OH　active　sites,　leading　to　the　reduced　activation　energy　barrier　for　–C–H　bond　dissociation.　The　present　work　sets　forth　the　structure-function　relationship,　identifying　opportunities　for　rational　design　of　highly　efficient　BCN　catalysts　for　ODH　reactions.　©　2021　Elsevier　Inc.