^(57)Fe穆斯堡尔谱研究Ir-Fe催化剂用于CO选择氧化反应(英文)  

^(57)Fe Mssbauer Spectroscopy of Ir-Fe Catalysts for Preferential CO Oxidation in H_2

作　　者：刘阔[1,2] 张万生[1] 王军虎[1] 王爱琴[1] 黄延强[1] 金长子[1] 沈俭一[3] 张涛[1] 

机构地区：[1]中国科学院大连化学物理研究所催化基础国家重点实验室,辽宁大连116023 [2]中国科学院研究生院,北京100049 [3]南京大学化学化工学院,江苏南京210093

出　　处：《催化学报》2010年第11期1335-1341,共7页

基　　金：Supported by the Hundred Talents Program of Chinese Academy of Sciences and the National Natural Science Foundation of China (20325620, 20773122, and 20673055)

摘　　要：采用不同浸渍顺序制备了三种Ir-Fe催化剂,其CO选择氧化(PROX)反应活性差别很大,其中共浸渍的Ir-Fe催化剂活性最高.吸附量热研究表明,三种催化剂的H2和CO吸附存在差别.通过对三种催化剂还原后、再氧化和反应后准原位57Fe穆斯堡尔谱的研究,得到各种Fe物种信息.结果表明,三种制备方法影响催化剂中Ir-Fe相互作用强度,导致催化剂中Fe物种的氧化还原性能不同.催化剂中Fe2+(a)的含量与CO转化率呈正比关系,Fe2+(a)是PROX反应过程中活化氧的活性中心.浸渍顺序改变了Ir-Fe间相互作用强度,从而改变Fe2+(a)物种含量,影响PROX反应活性.Ir-Fe间的相互作用可以稳定活化氧的Fe2+(a)物种,为今后研究金属-金属间的相互作用提供借鉴.New insights on the interaction between Ir and Fe oxide are reported.Three Ir-Fe catalysts were prepared by different impregnation sequences of an Al2O3 support.Co-impregnation gave a better catalyst for the preferential CO oxidation in H2（PROX） reaction.Microcalorimetry data showed that the adsorption of CO and H2 were different.Quasi in situ Mssbauer data of the three catalysts after reduction,reoxidation,and PROX reaction showed that a strong interaction between Ir and Fe affected the redox properties of the Ir-Fe catalysts.CO conversion was proportional to the concentration of the Fe2＋（a） species,thus,Fe2＋（a） was an active site in the PROX reaction.The impregnation sequence influenced the interaction between Ir and Fe and consequently,the amount of the active Fe2＋（a） species.A strong Ir-Fe interaction stabilized the active Fe2＋ sites for activating O2.

关 键 词：一氧化碳 选择氧化 铱 铁 准原位穆斯堡尔谱 吸附量热 金属-金属相互作用 

分 类 号：O643.36[理学—物理化学]