通过并流共沉淀方法,制备了一系列添加助剂ZrO2和Nb2O5的Au/α-Fe2O3催化剂,并用紫外-可见漫反射光谱,X射线光电子能谱,透射电镜和X射线荧光元素分析对其进行了表征。结果表明ZrO2和Nb2O5之间存在着较强的协同作用;两种助剂的同时添加促进了Au,ZrO2和Nb2O5在Au/α-Fe2O3催化剂表面的富集,有效地阻止了纳米微粒的团聚。经甲醇重整气氛下的催化性能评价,在200℃时,AuFZN的活性达到平衡转化率99.9%;经50h的稳定性测试,其稳定性远远高于未加助剂的Au/α-Fe2O3样品。这表明ZrO2和Nb2O5双助剂的添加有效地改善了Au/α-Fe2O3催化剂的性能。
A series of Au/α-Fe2 O3 catalysts promoted with ZrO2 and Nb2 O5 were prepared by parallel co-precipitation method. Detailed characterizations were conducted by techniques including UV-Vis-DRS, XPS, TEM and XRF. Results indicated that the enrichment of Au, ZrO2 and Nb2O5 on the surface induced by the strong interaction between ZrO2 and Nb2O5 kept the nanoparticles apart, delaying sintering. Performance tests carried out in the reformed methanol steam showed that its CO conversion almost reached the maximum value of 99% at 200 ℃, and maintained a better stability compared with unmodified samples within 50 h on-stream. All these indicated that ZrO2 and Nb2O5 promoters efficiently improved the performance of the Au/α-Fe2O3 catalysts.