reported the dehydration of ethanol over SAPO-11 catalyst. The yield of ethylene achieved about 90% at 320 8C. In order to improve the yield of ethylene, Zhang et al. [13] chose metal doped-SAPO as catalyst, the best yield of ethylene was 92.3% for dehydration of ethanol at 350 8C over Ni-substituted SAPO-34. Unfortunately, the yield only increased about 2% at the cost of improving temperature by 30 8C. So far dehydration reaction of bio-ethanol to ethylene has been studied extensively. Thus, a systematic study is necessary for investigating the influence of reaction conditions on the catalytic properties over modified SAPO.