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.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
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)
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
EDTA modification
barium doped nano-magnesia
ruthenium catalyst
ammonia synthesis
complexing agent effect
作者简介
霍超，女，1971年生，博士，教授，浙江工业大学化学工程学院，浙江杭州310014，电话：0571-88320815，E-mail：chaohc@zjut．edu．cn
