Selective　oxidation　of　alcohols　to　aldehydes　is　widely　applicable　to　the　synthesis　of　various　green　chemicals.　The　poor　chemoselectivity　for　complicated　primary　aldehydes　over　state-of-the-art　metal-free　or　metal-based　catalysts　represents　a　major　obstacle　for　industrial　application.　Bucky　nanodiamond　is　a　potential　green　catalyst　that　exhibits　excellent　chemoselectivity　and　cycling　stability　for　the　selective　oxidation　of　primary　alcohols　in　diverse　structures　(22　examples,　including　aromatic,　substituted　aromatic,　unsaturated,　heterocyclic,　and　linear　chain　alcohols)　to　their　corresponding　aldehydes.　The　results　are　comparable　to　reported　transition-metal　catalysts　including　conventional　Pt/C　and　Ru/C　catalysts　for　certain　substrates　under　solvent-free　conditions.　The　possible　activation　process　of　the　oxidant　and　substrates　by　the　surface　oxygen　groups　and　defect　species　are　revealed　with　model　catalysts,　ex　situ　electrochemical　measurements,　and　ex　situ　attenuated　total　reflectance.　The　zigzag　edges　of　sp　2　carbon　planes　are　shown　to　play　a　key　role　in　these　reactions.　©　2017　Wiley-VCH　Verlag　GmbH　&　Co.　KGaA,　Weinheim