Selective Methanol Oxidation to Hydrogen over Ag/ZnO Catalysts Doped with Mono- and Bi-Rare Earth Oxides
Selective Methanol Oxidation to Hydrogen over Ag/ZnO Catalysts Doped with Mono- and Bi-Rare Earth Oxides
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DOI：
10.1021/ie502609z
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发表时间：
2014-12
影响因子：
4.2
通讯作者：
H. AbdelDayem;S. Al-Shihry;S. Hassan
中科院分区：
文献类型：
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作者：
H. AbdelDayem;S. Al-Shihry;S. Hassan
研究了稀土氧化物（RE = La, Dy, Gd, Ce）修饰ZnO负载银催化剂和ce1 - xgdxoy修饰ZnO负载银催化剂上甲醇部分氧化制氢的反应。在150 ~ 400℃范围内研究了温度对催化剂活性的影响，并采用时序（TOS）法监测催化剂的稳定性。稀土金属氧化物促进剂的加入使催化剂的催化性能有了明显的提高。在350℃条件下，AgCe20Zn的甲醇氧化性能最佳，氢选择性为90.8%，甲醇转化率为95.2%；然而，催化剂在TOS作用下明显失活。用钆助剂验证了Ag/ZnO催化剂的良好稳定性。用Gd掺杂AgCe20Zn催化剂，大大提高了AgCe20Zn催化剂至少24 h的使用寿命，并显著降低了CO含量（降至<1%）。x射线衍射分析…
The hydrogen production by the catalytic partial oxidation of methanol (POM) over rare earth oxide (RE = La, Dy, Gd, and Ce)-modified ZnO-supported silver catalysts, as well as silver supported on Ce1–xGdxOy-modified ZnO catalysts, was investigated. The effect of the temperature on the activity was studied in the range between 150 and 400 °C, and the catalyst stability was monitored with time-on-stream (TOS). The addition of rare earth metal oxide promoters resulted in a significant improvement in the catalytic performance. The optimal performance in methanol oxidation was achieved using AgCe20Zn, which exhibited a hydrogen selectivity of 90.8% with 95.2% methanol conversion at 350 °C; however, the catalyst suffered from marked deactivation with TOS. The good stability of the Ag/ZnO catalyst was verified using a gadolinium promoter. Doping of the AgCe20Zn catalyst by Gd greatly enhanced its life span over at least 24 h on-stream and markedly reduced the CO content (down to <1%). X-ray diffraction analysis...