A　novel　non-noble　electrocatalyst　with　an　average　particle　size　of　approximately　4　nm　was　prepared　by　heat-treating　carbon-supported　molybdenum　tetraphenylporphyrin　in　a　flow　NH3　atmosphere.　The　effects　of　heating　time　and　temperature　on　its　electrocatalystic　properties　were　investigated.　The　samples　obtained　were　characterized　by　X-ray　diffraction,　transmission　electron　microscopy,　X-ray　photoelectron　spectroscopy,　and　EDX.　The　results　show　that　the　synthesized　catalyst　has　the　same　composition　as　that　of　MoN.　This　carbon-supported　catalyst　displays　a　strong　activity　towards　oxygen　reduction　reaction　(ORR)　and　a　methanol-tolerant　property.　The　catalyzed　ORR　proceeds　by　an　approximate　four-electron　reduction　pathway　from　O-2　directly　to　H2O.　(C)　2007　Elsevier　B.V　All　rights　reserved.