TiO_(2)-facet-dependent effect on methane combustion over Ir/TiO_(2)catalysts  

Ir/TiO_(2)催化剂甲烷燃烧反应中TiO_(2)晶面依赖效应

作　　者：Huimei Duan Xiaofei Li Chuanhui Wang Congyun Zhang Kaiwen Yu Lei Chen Yunshang Zhang Jiabin Ji Xianfeng Yang Dongjiang Yang 段会梅;李晓菲;王传辉;张丛筠;余楷文;陈磊;张云尚;纪嘉宾;杨贤峰;杨东江(青岛大学环境科学与工程学院,生物纤维与生态纺织品国家重点实验室,山东青岛266071;昆士兰大学环境学院,澳大利亚昆士兰州布里斯班;中国科学技术大学化学物理系,安徽省表界面化学与能源催化重点实验室,安徽合肥230026;华南理工大学分析测试中心,广东广州510640;宁波工业大学微纳材料与器件研究所,浙江宁波315211)

机构地区：[1]School of Environmental Science and Engineering,State Key Laboratory of Bio-fibers and Eco-textiles,Qingdao University,Qingdao 266071,Shandong,China [2]School of the Environment,The University of Queensland,Brisbane,QLD,4072,Australia [3]Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes,Department of Chemical Physics,University of Science and Technology of China,Hefei 230026,Anhui,China [4]Analytical and Testing Centre,South China University of Technology,Guangzhou 510640,Guangdong,China [5]Institute of Micro/Nano Materials and Devices,Ningbo University of Technology,Ningbo 315211,Zhejiang,China

出　　处：《Chinese Journal of Catalysis》2025年第3期378-387,共10页催化学报(英文)

基　　金：国家自然科学基金(22376110);山东省自然科学基金(ZR2023ME098,ZR2021QB083);青岛市应用基础研究项目(RZ2200001413);生物纤维与生态纺织品国家重点实验室(青岛大学,RZ2000004399).

摘　　要：Engineering the morphology of the support is effective in tuning the redox properties of active metals for efficient catalytic methane combustion via tailoring the metal-support interaction.Herein,uniform Ir nanoparticles supported on anatase TiO_(2)with different morphologies predominantly exposing{100},{101},and{001}planes were synthesized and tested for methane combustion.The CH_(4) catalytic activity shows a remarkable TiO_(2)-facet-dependent effect and follows the order of Ir/TiO_(2)-{100}>Ir/TiO_(2)-{101}>>Ir/TiO_(2)-{001}.Detailed characterizations and DFT calculations reveal that compared with Ir-TiO_(2)-{101}and Ir-TiO_(2)-{001}interfaces,the superior Ir-TiO_(2)-{100}interface facilitates the generation of electron-rich Ir species through more profound charge transfer from TiO_(2)-{100}to Ir atoms.The electron-rich Ir structure,featuring abundant defect oxygen vacancies,significantly enhances the redox properties of active Ir species and reduces the activation energy for breaking the initial C-H bond in CH_(4),resulting in the superior catalytic activity for methane combustion.These findings deepen fundamental insights into the TiO_(2)-facet-dependent reactivity of different Ir/TiO_(2)nanomaterials in methane oxidation and pave the way for designing efficient Ir-based methane oxidation catalysts.甲烷作为一种清洁能源,也是一种强温室效应气体.在天然气汽车尾气净化、天然气电厂尾气处理、乏风瓦斯和油田伴生气处理等过程中,大量低浓度未燃尽甲烷的直接排放会造成严重的能量损失和温室效应.甲烷催化燃烧是一种有效处理低浓度甲烷的净化技术.负载型Ir催化剂,特别是负载在TiO_(2)载体上的Ir基催化剂,因其较好的低温活化甲烷能力而受到越来越多的关注.活性金属的氧化还原性能对催化剂的甲烷燃烧性能至关重要.载体形貌工程借助金属-载体相互作用可有效调控活性金属的氧化还原性能.然而至今,TiO_(2)暴露晶面对Ir/TiO_(2)催化剂甲烷燃烧性能影响及其相关机制研究尚不清楚,阐明TiO_(2)暴露面与Ir/TiCO_(2)催化剂甲烷燃烧反应活性之间的结构-性能关系具有重要意义.本文首先制备了主要暴露{100},{101}和{001}晶面的TiO_(2)纳米晶,采用湿化学法制备了均匀负载的Ir/TiO_(2)纳米催化剂,并用于甲烷催化燃烧性能评估.研究发现,TiO_(2)暴露晶面显著影响了Ir/TiO_(2)催化剂的甲烷燃烧催化性能,活性顺序为Ir/TiO_(2)-{100}>Ir/TiO_(2)-{101}>>Ir/TiO_(2)-{001}.TiO_(2)显著的晶面依赖效应与催化剂中不同电子金属-载体相互作用(EMSI)和氧空位紧密相关.相比于Ir-TiO_(2)-{101}和Ir-TiO_(2)-{001}界面Ir-TiO_(2)-{100}界面处具有更强的电子转移TiO_(2)→Ir,诱导了富电子Ir物种的形成.原位红外漫反射结合密度泛函理论计算研究发现,相比于Ir/TiO_(2)-{101}和Ir/TiO_(2)-{001}催化剂,Ir-TiO_(2)-{100}催化剂表面更易发生CH_(4)分子中C-H的断裂.Ir/TiO_(2)-{100}催化剂中富电子Ir结构和丰富的氧空位极大地增强了活性Ir物种的氧化还原性能,加速了CH_(4)和O_(2)分子在催化剂表面的吸附和活化,进而显著增强了甲烷氧化催化性能.本文清楚阐明了Ir/TiO_(2)催化剂在甲烷燃烧反应中TiO_(2)晶面依赖效应,加深了Ir纳米催化反应体�

关 键 词：Ir/TiO_(2) TiO_(2)-facet-dependent Methane combustion Oxygen vacancies Metal-support interaction 

分 类 号：O643.36[理学—物理化学]