富氧条件下流化床内Ru基双贵金属催化去除碳颗粒  

Catalytic removal of soot over Ru-based bimetallic noble catalysts in fluidized bed reactor under oxygen-rich condition

作　　者：郭明新[1] 欧阳峰[1] 苏俊涛[1] 朱荣淑[1] 

机构地区：[1]哈尔滨工业大学深圳研究生院环境科学与工程研究中心,广东深圳518055

出　　处：《环境污染与防治》2012年第10期23-27,32,共6页Environmental Pollution & Control

基　　金：深圳双百计划资助项目(No.2008)

摘　　要：采用等体积浸渍法制备了系列Ru基双贵金属催化剂。利用程序升温技术研究了富氧条件下Ru基双贵金属催化剂催化氧化碳颗粒的反应,考察了双贵金属活性组分比例、载体以及双贵金属组合对催化活性的影响。还对固定床与流化床内碳颗粒氧化进行了比较,分析了流化床内碳颗粒低温氧化的原因。结果表明,双贵金属摩尔比为1∶1时具有较高的催化活性,复合载体TiO2/SiO2更易与双贵金属组分形成协同效应,不同贵金属取代形成的双贵金属催化剂中,Ru-X/TiO2/SiO2(X=Rh、Ag和Ir)的催化活性较高。与固定床相比,流化床因其良好的传热和传质特性,使得碳颗粒催化氧化温度最多可降低50℃左右。流化床是一种类似于尾气中气流流动状态的反应装置,具有潜在的应用前景。Series of Ru-based bimetallic noble catalysts Ru-X （X：Rh, Pd, Ag, Ir, Pt and Au） were prepared by supporting two noble metals on MOx/SiO2 （M=None, Al, Ti and Zr） using impregnation method. Oxidation of soot over catalysts has been conducted in fluidized bed reactor with temperature programmed reaction （TPR） technique. The effects of molar ratio and combination of Ru and noble metal X as well as supporters on the activity in the soot oxidation have been investigated. Meanwhile, the soot oxidation in fluidized bed and fix bed reactors are contras- ted, the reason of soot low temperature oxidation in fluidized bed is analyzed. Results showed that Ru-X exhibited the high catalytic activity and selectivity to CO2 when the molar ratio of two noble metals is 1 ~ 1. Among MOx/SiO~, synergetic effect appeared between TiO2/SiO2 and bimetallic noble. Ru-Rh/Ti02/Si02, Ru-Ag/TiO2/SiO2 and Ru-Ir/TiO2/SiO2 presented a higher activity among Ru-X/TiO2/SiO2 catalysts. Compared to soot oxidation in fixed bed reactor, the oxidation of soot was accomplished at low temperature and this can be attributed to the promotion of mass transfer in fluidized bed reactor,indicating that soot oxidation in fluidized bed reactor is a promising method for application in diesel exhaust.

关 键 词：双贵金属 富氧 碳颗粒 流化床 RU 

分 类 号：X734.2[环境科学与工程—环境工程] O657.32[理学—分析化学]