La助剂对甲醇水蒸气转化制氢CuO-ZnO/Al_2O_3催化剂性能的影响

研究了La助剂对CuO -ZnO/Al2 O3催化剂性能的影响 ,得到了活性和稳定性较好的CuO -ZnO -La2 O3/Al2 O3催化剂。应用TPR、XRD、SEM及XPS等方法对催化剂进行了表征 ,结果表明 :La助剂的加入使催化剂表面的Cu组份含量增加并使Cu/Zn摩尔比提高 ;La助剂的加入极大地提高了催化剂的稳定性 ;反应过程中催化剂表面Cu组份含量逐渐下降是催化剂活性下降的直接原因。

Effects of La-Promoter on Catalytic Performance of CuO-ZnO/Al_2O_3 Catalyst for Steam Reforming of Methanol

La promoted CuO-ZnO/Al 2O 3 catalyst for steam reforming of methanol was prepared.A series of techniques,such as TPR,XRD,SEM and XPS,were used to characterize the catalysts with or without La- promoter. TPR and XPS results showed that the dispersion of copper on catalyst surface was influenced greatly by La-promoter,Cu/Zn atom ratio on the surface of CuO-ZnO-La 2O 3/Al 2O 3 was 1.24,while on the surface of CuO-ZnO/Al 2O 3 it was 0.69.Copper content on the catalyst surface decreased greatly after stability test,which was one of the main reasons of catalyst deactivation.When La-promoter was added to CuO-ZnO/Al 2O 3 catalyst,its activity and stability improved greatly;during the 600 h stability test of CuO-ZnO-La 2O 3/Al 2O 3 catalyst,CH 3OH conversion was between 87.5%～92.5%,and CO content was less than 0.35%. WT5HZ]