Pd and PdAu on mesoporous silica for methane oxidation: Effect of SO2
Pd and PdAu on mesoporous silica for methane oxidation: Effect of SO2
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DOI：
10.1016/j.jcat.2007.07.013
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发表时间：
2007-10
影响因子：
7.3
通讯作者：
A. Venezia;R. Murania;G. Pantaleo;G. Deganello
中科院分区：
文献类型：
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作者：
A. Venezia;R. Murania;G. Pantaleo;G. Deganello
采用浸渍法制备了以介孔二氧化硅为载体的钯催化剂和金-钯催化剂。用XPS、X射线衍射仪、比表面积法和傅里叶变换红外光谱对其进行了表征。在贫氧条件下对甲烷的氧化反应进行了活性测试。考察了在反应物中加入SO2对反应的影响。连续进行试验反应，评价其热稳定性和中毒可逆性。在起燃温度(t50<；300 °C)和耐SO2方面，钯催化剂表现得很好。此外，在350 °C的SO2中夜间处理后活性下降，在随后的循环中完全恢复。金的存在略微降低了酶的活性，但不改变对SO2的耐受性。从金促进的样品中获得了在钯表面发生动态还原-氧化过程的证据，其中确定了SO2处理时钯的还原。
Palladium and gold–palladium catalysts supported on mesoporous silica were prepared by incipient wetness impregnation. They were characterized by XPS, XRD, BET, and FTIR acidity measurements. The activity was tested in the oxidation of methane under lean conditions. The effect of adding SO2to the reactant mixture was investigated. Test reactions were consecutively performed to evaluate the thermal stability and poisoning reversibility. The palladium catalyst performed quite well in terms of the light-off temperature (T50<300 °C) and SO2tolerance. Moreover, the activity, which decreased after a night treatment in SO2at 350 °C, was completely recovered in subsequent cycles. The presence of gold decreased the activity slightly without altering the SO2tolerance. Evidence of a dynamic reduction–oxidation process occurring at the palladium surface was obtained from the gold-promoted sample in which the reduction of palladium on SO2treatment was ascertained.