The　NO　oxidation　on　Cu2O(111)　with　molecular　oxygen,　dissociated　oxygen,　and　lattice　O,　was　studied　by　using　periodic　density　functional　theory.　Cu2O　could　promote　NO　oxidation　via　the　more　favorable　Elay-Rideal　mechanism.　For　NO　oxidation　with　molecular　oxygen,　path　II　(NO　+　O2∗　→　O∗ONO　→　NO2　+　O∗;　NO　+　O∗→　NO2∗→　NO2)　was　found　as　the　most　probable　route,　in　which　NO2　desorption　is　the　reaction　rate　determining　step.　The　NO　oxidation　reaction　with　dissociated　oxygen　is　also　possible.　In　this　case,　O2　dissociation　occurs　after　surpassing　a　barrier　of　105　kJ/mol.　Thereafter,　NO　molecule　can　readily　react　with　oxygen　adatoms　without　barrier　or　with　a　moderate-low　barrier　of　49　kJ/mol.　Both　of　the　produced　NO2　molecules　will　release　from　the　surface.　The　barrier　to　be　surmounted　is　53.3　and　103.2　kJ/mol,　respectively.　The　reaction　of　NO　with　lattice　O　has　a　high　barrier　and　it　is　very　unlikely.　The　present　results　enrich　our　understanding　of　the　catalytic　oxidation　of　NO　by　metal-oxide　catalysts.　©　2014　Elsevier　B.V.　All　rights　reserved.