EDTA修饰对Ru/Ba-MgO氨合成催化剂性能的影响及作用机理（英文）  

Influence of Ethylene Diamine Tetraacetic Acid on the Performance of Magnesia Supported Ru-based Catalysts for Ammonia Synthesis

作　　者：霍超[1] 程向炜[1,2] 杜彦磊[1] 

机构地区：[1]浙江工业大学,浙江杭州310014 [2]浙江警察学院,浙江杭州310053

出　　处：《稀有金属材料与工程》2017年第3期657-662,共6页Rare Metal Materials and Engineering

基　　金：the Public Technology Research(Test)Program of Zhejiang Province of China(2014C37048)

摘　　要：利用超声-共沉淀技术制备了一系列EDTA修饰的掺钡纳米氧化镁载体(EDTA-Ba-MgO)及其负载的钌基氨合成催化剂(Ru/EDTA-Ba-MgO)。通过场发射扫描电镜、X射线粉末衍射仪、氮物理吸附、热重分析仪及H_2程序升温还原等方法对载体/催化剂进行表征。结果表明:EDTA的修饰作用改变了钡助剂与载体的作用方式,通过与Ba助剂发生络合作用形成了[Ba(EDTA)]^(2-),改变了Ba^(2+)的带电性质,使钡助剂在带正电荷的载体表面实现了直接吸附,从而更有利于对钡助剂在Ba-MgO中掺杂量及掺杂形式的调控,最终达到提高催化剂活性的目的。在10 MPa,10 000 h^(-1)和698 K的反应条件下,Ru/EDTA-Ba-MgO催化剂上氨合成速率达到69.31 mmol·(g·h)^(-1),比Ru/Ba-MgO提高了7.4%。A series of barium doped nano-magnesia supports （Ba-MgO） modified with ethylene diamine tetraacetic acid （EDTA） were prepared by chemical co-precipitation with an ultrasonic method and were used as supports to prepare Ru-based catalysts. The surface texture and the matter phase of the supports and Ru catalysts were characterized by X-ray diffraction, scanning electron microscope, N2 physical-adsorption, HE temperature-programmed reduction and inductively coupled plasma-atomic emission spectrometry. The results show that modification of EDTA increases the amount of barium promoter into the support and controls the formation state of barium in supports. The effects of barium promoter content and surface texture in supports achieve an equilibrium state when the molar ratio of EDTA to Ba is 1/2, and the highest activity of Ru/Ba-MgO catalyst is 69.31 mmol.（g.h）-1 under the reaction conditions of 10 MPa, 10 000 h-1 and 698 K.

关 键 词：EDTA修饰 掺钡纳米氧化镁 钌基催化剂 氨合成 络合作用 

分 类 号：O643.36[理学—物理化学]