模型催化剂表面上CO加氢的原位谱学研究
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- 英文论文题名：In-situ spectrum study of CO hydrogenation on model catalyst surfaces
- 论文作者：陈明树 ; 万惠霖
- 英文论文作者：Mingshu Chen ; Huilin Wan ; State Key Laboratory of Physical Chemistry of Solid Surfaces ; National Engineering Laboratory for Green Chemical Productions of Alcohols-Ethers-Esters ; Department of Chemistry ; College of Chemistry and Chemical Engineering ; Xiamen University
- 年：2016
- 作者机构：固体表面物理化学国家重点实验室醇醚酯化工清洁生产国家工程实验室厦门大学化学化工学院化学系厦门大学;
- 论文关键词：多相催化 ; 模型催化 ; 催化反应机理 ; 催化剂活性中心
- 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：179k
- 原文格式：D
- 会议级别：全国
摘要
模型催化研究是基于研制具结构规整性的模型催化剂表面,特别是在超高真空条件下研制原子水平清洁的模型表面,研究结构与催化活性/选择性的一一对应关系,并结合无温度、压力差距的原位表征手段检测表面状态/活性物种,从而能得到更为准确的催化活性位本质、活性物种及催化反应机理。本报告报道制备了Cu/Al_2O_3/Zn O(0001)-Zn,FeO_x/Rh(111)和M O_x/Rh(111)等模型催化剂并用XPS,LEIS,AES,LEED,STM和IRAS进行表征。结果表明在Zn O(0001)-Zn面上Al_2O_3可以按层-层模式生长,而Cu仅在很低覆盖度以二维岛生长然后形成三维纳米簇。适量Al_2O_3可以抑制铜的还原,并提高Cu~+的浓度,这可能与其对甲醇合成性能的促进作用有关。亚单层的Fe Ox和MnO_x对Rh表面上CO加氢性能有明显的促进作用,提高其烯烃和乙醇的选择性。
The model catalysts of Cu/Al_2O_3/ZnO(0001)-Zn,FeO_x/Rh(111) and MnO_x/Rh(111) have been prepared and characterized using XPS,LEIS,AES,LEED,STM,IRAS.The deposition rates and growth models were carefully checked with varying the preparation conditions.It was found that Al_2O_3 grew on the Zn O(0001)-Zn surface by a layer-by-layer model,while Cu formed two-dimensional islands only at a low coverage and three dimensional clusters at a high coverage.Comparing to the Cu/Zn O binary model catalyst,the addition of Al_2O_3 obviously slowed down the reduction of Cu/Al_2O_3/Zn O by H_2.More significantly,the existence of Al_2O_3 in the ternary model catalyst leaded to an increase of Cu~+ concentration.The enhancement of Al_2O_3 in Cu/Al_2O_3/Zn O(0001)-Zn for methanol synthesis may origin from that the Al_2O_3 helps to stabilize the surface Cu~+ which has been proposed as one of the active sites.Submonolayer of Fe Ox and MnO_x were found to significantly modify the catalytic properties for CO hydrogenation on Rh(111),and to enhance the seclectivities of ethene and ethanol.
The model catalysts of Cu/Al_2O_3/ZnO(0001)-Zn,FeO_x/Rh(111) and MnO_x/Rh(111) have been prepared and characterized using XPS,LEIS,AES,LEED,STM,IRAS.The deposition rates and growth models were carefully checked with varying the preparation conditions.It was found that Al_2O_3 grew on the Zn O(0001)-Zn surface by a layer-by-layer model,while Cu formed two-dimensional islands only at a low coverage and three dimensional clusters at a high coverage.Comparing to the Cu/Zn O binary model catalyst,the addition of Al_2O_3 obviously slowed down the reduction of Cu/Al_2O_3/Zn O by H_2.More significantly,the existence of Al_2O_3 in the ternary model catalyst leaded to an increase of Cu~+ concentration.The enhancement of Al_2O_3 in Cu/Al_2O_3/Zn O(0001)-Zn for methanol synthesis may origin from that the Al_2O_3 helps to stabilize the surface Cu~+ which has been proposed as one of the active sites.Submonolayer of Fe Ox and MnO_x were found to significantly modify the catalytic properties for CO hydrogenation on Rh(111),and to enhance the seclectivities of ethene and ethanol.
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