金红石型SnO_2在金红石和锐钛矿型TiO_2载体上的分散:相似相分散行为初探
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- 英文论文题名：Rutile SnO_2 dispersed on rutile and anatase TiO_2 supports:studies on like-disperses-like behavior
- 论文作者：徐香兰 ; 刘芳 ; 李林 ; 彭洪根 ; 方修忠 ; 刘文明 ; 王翔
- 英文论文作者：Xianglan Xu ; Fang Liu ; Lin Li ; Honggen Peng ; Xiuzhong Fang ; Wenming Liu ; Xiang Wang ; College of Chemistry ; Nanchang University
- 年：2016
- 作者机构：南昌大学化学学院;
- 论文关键词：负载型催化剂 ; 单层分散阈值 ; 相似相分散 ; XRD外推法
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第十五分会：表界面结构调控与催化
- 语种：中文
- 分类号：O643.36
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第十五分会 ; 表界面结构调控与催化
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：203k
- 原文格式：D
- 会议级别：全国
摘要
氧化物和盐类在载体上具有自发单层分散的倾向,形成二维单层或亚单层结构[1]。当活性组分负载量为单层分散阈值、呈单层分散时,催化剂往往表现出高活性和高选择性的阈值效应[2]。本文采用XRD外推法[3],测定了金红石型SnO_2在金红石型和锐钛矿型TiO_2上的单层分散阈值,结果如图1。SnO_2在金红石型TiO_2上分散阈值为0.682 mmol/100 m~2,远大于SnO_2在锐钛矿型TiO_2上的单层分散阈值(0.086 mmol/100 m~2),表明载体与分散组分具有相同晶型时,有助于活性组分的高分散。类似于溶液中存在"相似相溶"原理,本文提出"相似相分散"原理,即负载组分与载体结构相同或相似时,更利于分散。根据"相似相分散"原理,采用与活性组分结构相似的载体可能获得具有更高分散度的负载型催化剂,在催化剂的设计和制备中具有重要的理论及实际意义。
It is a common phenomenon and thermodynamic favored for oxides and salts to disperse spontaneously onto the surfaces of supports to form a monolayer or sub-monolayer [1].A catalyst with a loading of the active component at a monolayer dispersion capacity usually shows positive catalytic properties,such as higher activity and selectivity [2].The monolayer dispersion capacities of rutile SnO_2 supported on rutile and anatase TiO_2 supports were investigated and quantified by XRD extrapolation method [3].As shown in Fig.1,the monolayer dispersion capacity of SnO_2 on rutile TiO_2(0.682 mmol/100 m~2) is much higher than that on anatase TiO_2(0.086 mmol/100 m~2),which indicates that if an oxide support and a supported active phase have similar crystalline structure,it is favourable for the supported active phase to form more highly dispersed states.This phenomenon is named by us as like-disperses-like behavior,which is similar to the famous like-dissolves-like rule for solutions.The presence of this behavior could be potentially valuable for designing and preparing highly dispersed catalysts with improved performance.
It is a common phenomenon and thermodynamic favored for oxides and salts to disperse spontaneously onto the surfaces of supports to form a monolayer or sub-monolayer [1].A catalyst with a loading of the active component at a monolayer dispersion capacity usually shows positive catalytic properties,such as higher activity and selectivity [2].The monolayer dispersion capacities of rutile SnO_2 supported on rutile and anatase TiO_2 supports were investigated and quantified by XRD extrapolation method [3].As shown in Fig.1,the monolayer dispersion capacity of SnO_2 on rutile TiO_2(0.682 mmol/100 m~2) is much higher than that on anatase TiO_2(0.086 mmol/100 m~2),which indicates that if an oxide support and a supported active phase have similar crystalline structure,it is favourable for the supported active phase to form more highly dispersed states.This phenomenon is named by us as like-disperses-like behavior,which is similar to the famous like-dissolves-like rule for solutions.The presence of this behavior could be potentially valuable for designing and preparing highly dispersed catalysts with improved performance.
引文
[1]Xie,Y.C.;Tang,Y.Q.Adv.Catal.1990,37,1.
[2]Wachs,I.E.;Dalton Trans.,2013,42,11762.
[3]刘英骏,谢有畅,明晶,刘军,唐有祺,催化学报,1982,3(4),262.
[2]Wachs,I.E.;Dalton Trans.,2013,42,11762.
[3]刘英骏,谢有畅,明晶,刘军,唐有祺,催化学报,1982,3(4),262.