The catalytic ammoxidation of ethane with oxygen and ammonia was investigated over a series(Sb2O3) promoted ion-exchanged Co-ZSM-5 zeolites(Sb2O3/Co-ZSM-5).The introduction of appropriate amount of Sb2O3 can considerably improve the conversion of ethane,suppress the formation of COx,and increase the total C2 selectivity to acetonitrile and ethylene.Among them,the sample with 5% Sb2O3 loading(in mass fraction) shows a 68.4% ethane conversion at 550 ℃, a 51.6% selectivity to acetonitrile and a 31.7% selectivity to ethylene,and a 35.3% yield of acetonitrile were obtained,which is to our knowledge the highest ever reported for the direct ammoxidation of ethane.