Zr掺杂对PdO/Ce_(1-x)Pd_xO_(2-δ)催化剂CO和CH_4催化氧化的影响（英文）  

Effects of Zr Addition on CO and CH_4 Catalytic Oxidation over PdO/Ce_(1-x)Pd_xO_(2-δ) Catalyst

作　　者：贾永昌[1] 王树元[1] 孟涟[1] 鲁继青[1] 罗孟飞[1] 

机构地区：[1]浙江师范大学物理化学研究所先进催化材料教育部重点实验室,浙江金华321004

出　　处：《物理化学学报》2016年第7期1801-1809,共9页Acta Physico-Chimica Sinica

基　　金：supported by the National Natural Science Foundation of China(21203167,21173195);Zhejiang Province Public Technology Applied Research Projects,China(2013C31049)~~

摘　　要：采用溶液燃烧法制备出PdO/Ce_(1-x)Pd_xO_(2-δ)和PdO/Ce_(1-x)Pd_xO_(2-δ)(Pd O/CPZ)催化剂,通过硝酸处理去除催化剂表面的Pd O物种得到对应的Ce_(1-x)Pd_xO_(2-δ)(CP)和Ce_(1-x)Pd_xO_(2-δ)(CPZ)催化剂。考究四种催化剂(Pd O/CP、Pd O/CPZ、CP、CPZ)对CO和CH_4的氧化活性,并计算得出表面Pd O和Pdn+物种的转化频率(TOF)。结果表明Zr的添加对Pd O催化剂上CO和CH_4的催化氧化活性具有不同的影响。Zr的添加对Pd O/CPZ和CPZ催化剂的CO催化活性具有明显的促进作用,前者归因于PdO/CPZ催化剂表面生成了更小颗粒的Pd O粒子,后者归因于CPZ催化剂中含有更多的氧空位。对于CH_4的催化氧化,Pd^(n+)物种起到关键的作用。由于Zr的掺杂导致Ce O2的晶格中Pd物种的含量减少,致使PdO/CPZ催化剂和CPZ催化剂对CH_4氧化活性的降低。PdO/Ce（1-x）PdxO（2-δ）（Pd O/CP） and PdO/Ce（1-x）PdxO（2-δ）（Pd O/CPZ） catalysts were prepared via a solution combustion method. The corresponding Ce1-xPdxO2-δ（CP） and Ce（1-x-y）PdxZryO（2-δ）（CPZ） catalysts were obtained by nitric acid treatment of the Pd O/CP and Pd O/CPZ catalysts to remove the surface Pd O species.These catalysts were tested for CO and CH4 catalytic oxidation. The turnover frequencies（TOFs） of surface Pd O and Pdn＋cations in the CP and CPZ solid solutions were calculated. The results showed that Zr addition in the Pd O/CP catalyst had very different effects on CO and CH4 oxidation. A significant improvement in CO oxidation activity was observed over the Zr-containing catalysts; this could be related to the formation of smaller Pd O particles on the surface of the Pd O/CPZ catalyst and a higher oxygen vacancy concentration in the CPZ solid solution. For CH4 oxidation, Pdn ＋cations in the solid solution play a key role in the catalytic oxidation process. The penetration of Zr^（4＋）cations into the Ce O2 lattice decreased the amount of Pd^（2＋）cations in the CPZ solid solution and thus inhibited the activities of the Zr-containing catalysts（Pd O/CPZ and CPZ） for CH4 oxidation.

关 键 词：铈 氧化钯 氧空位 CO氧化 CH4氧化 

分 类 号：O643.36[理学—物理化学]