铈和镨改性Ni/Al_2O_3催化剂对甲醇水蒸气重整制氢的影响  

Effect of Cerium and Praseodymium Addition on Ni/Al_2O_3 Catalyst to Produce H_2 from Methanol Steam Reforming

作　　者：李晓峰[1] 王晶[1] 张磊[1] 雷燕秋 刘攀[1] 陈然[1] 陈柯臻 何素芳[1] 罗永明[1] 

机构地区：[1]昆明理工大学环境科学与工程学院,云南昆明650500

出　　处：《中国稀土学报》2016年第4期403-410,共8页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金项目(U1402233;21267011;21367015)资助

摘　　要：考察了Ni/Al_2O_3,Ce和Pr改性Ni/Al_2O_3催化剂在甲醇水蒸气重整制氢过程中的性能。研究结果表明:稀土的添加可增加H2的选择性并降低CO的选择性。Pr改性Ni/Al_2O_3催化剂表现出最好的催化性能,Ni的最佳负载量为10%(质量分数)。在相同的反应条件下(反应温度为350℃和水醇摩尔比=3∶1),Ni/Al_2O_3与Pr改性的Ni/Al_2O_3催化剂的甲醇转化率相当,但Pr改性的Ni/Al_2O_3催化剂H_2的选择性从64.5%提高到了75.6%,相应的CO选择性则从31.4%降低到了4.5%。H2选择性随着水醇摩尔比的增加而升高,当水醇摩尔比为6∶1时,几乎没有CO产生。XRD和TPR表征结果表明:Pr的添加不仅促进了Ni在载体上的分散而且促进了Ni的还原,从而有利于催化性能的改善。The catalytic performances of methanol steam reforming over Ni/Al2O3 and Ce and Pr modified Ni/Al2O3 catalysts were investigated. It was found that the addition of rare earth was in favor of improvement of selectivity of H2,but not for CO. The catalyst modified with Pr exhibited the best catalytic performances for methanol steam reforming,and the optimal loading of Ni was 10%. The conversion of methanol over Ni/Al2O3 was comparable to that of the Pr modified Ni/Al2O3 under the same reaction conditions（ reaction temperature = 350 ℃ and the mole ratio of H2O to CH3OH = 3 /1）. However,the selectivity of H2 over the latter increased from 64. 5% to 75. 6%,and the corresponding selectivity of CO decreased from 31. 4% to 4. 5%. It was also noted that the selectivity of CO decrease with further increasing the mole ratio of H2O to CH3OH,and almost no carbon monoxide was produced when the ratio increasing from 3 /1 to 6 /1. Based on the results of XRD and H2-TPR characterization,it could be concluded that the addition of Pr was not only beneficial to the dispersion of nickel species but also to the reduction,which should be responsible for the improvement of catalytic performances for methanol steam reforming.

关 键 词：稀土 Ce Pr NI/AL2O3催化剂 甲醇水蒸气重整 制氢 

分 类 号：X24[环境科学与工程—环境科学]