The　composited　catalyst　of　graphene　nanoribbons　supported　platinum-gold　nanoalloy　(PtAu/GNR)　was　prepared　by　microwave-assisted　polyol　method.　GNRs　network　is　a　suitable　carrier　to　support　metal　nanoparticles　dispersedly.　The　effects　of　new　GNR　support　and　PtAu　co-existence　on　the　electrocatalytic　performance　of　composite　catalyst　for　ethanol　oxidation　are　discussed.　For　further　analyzing　the　anti-CO　poisoning　capability,　the　electron　density　difference　and　the　electrostatic　potential　of　catalyst　surface,　and　the　energy　curve　of　CO　oxidation　reaction　are　calculated　theoretically　based　on　the　first　principle.　The　results　show　that　PtAu/GNR　has　much　superior　catalytic　activity　and　higher　poisoning　tolerance　than　the　monometal　composite　catalyst.　©　2015　Elsevier　Ltd.　All　rights　reserved.