尖晶石CuM2O4(M=Al、Fe、Cr)催化甲醇重整反应的特性

采用柠檬酸络合法,经900 ℃热处理制备了CuAl₂O₄、CuFe₂O₄和CuCr₂O₄三种尖晶石,并进行了甲醇重整性能评价。结合XRD、H₂-TPR、SEM和BET等表征,研究了铜基尖晶石的催化特性。结果表明,三种铜基尖晶石的形貌和大小有极大差异,表现出不同的催化性能,CuAl₂O₄尖晶石获得最优的稳定性和最低的CO选择性,CuFe₂O₄尖晶石上CO选择性最高且稳定性差,CuCr₂O₄尖晶石上石墨碳沉积最严重。根据长时间评价结果和表征数据发现,在反应气氛中铜基尖晶石不稳定,通过释放活性铜而起催化作用;同时铜的烧结长大与积炭现象共同影响催化性能。

Catalytic characteristics of spinel CuM2O4 (M=Al,Fe, Cr) for the steam reforming of methanol

Spinel oxides of CuAl₂O₄, CuFe₂O₄ and CuCr₂O₄ were prepared by citrate process at 900 ℃, and their catalytic properties for methanol steam reforming was evaluated. In combination with the XRD, H₂-TPR, SEM and BET data, the catalytic characteristics of spinel oxides were also discussed. The results showed that the morphology and size of the three spinel oxides were quite different and catalytic properties varied among the three spinel oxide catalysts. CuAl₂O spinel showed the highest stability and lowest CO selectivity while CuFe₂O₄ indicated the highest CO selectivity and poor stability and CuCr₂O₄ encountered serious coke deposition. It has been shown, according to the long test data and results, that active Cu species were released from copper based spinel during methanol steam reforming, and their catalytic performances were influenced by both Cu sintering and coke deposition.