摘要
多相催化臭氧化技术因能有效去除水中有机污染物而受到广泛关注.然而,基于单一位点氧化还原的金属氧化物催化臭氧化过程存在速率限制步骤,使活性受到抑制,极大地限制了多相催化臭氧化技术的实际应用.为解决这一瓶颈,以过渡金属物种Fe和Ti对金属氧化物γ-Al_(2)O_(3)基底进行晶格掺杂制备出新型双反应中心催化剂FT-A-1 DRCs.通过XRD、TEM和XPS等技术对其形貌结构和化学组成进行了表征分析,证明Fe和Ti对于Al的晶格取代,形成表面贫富电子微区(富电子Fe微中心和缺电子Ti微中心).FT-A-1 DRCs被用于催化臭氧化过程,对布洛芬等一系列难降解有机污染物的去除表现出优异的活性和稳定性.利用EPR和电化学技术揭示了界面反应机制.发现在催化臭氧化过程中,O_(3)/H_(2)O在富电子微中心被定向还原产生·OH,而污染物可在缺电子微中心作为电子供体而被氧化,为反应体系持续提供电子.这一反应过程利用污染物自身的能量实现了污染物的双途径降解(·OH攻击和直接电子供体),突破了金属氧化物催化臭氧化过程存在速率限制步骤.
Multiphase catalytic ozone oxidation technology has received wide attention for its effectiveness in removing organic pollutants from water. However,the existence of a rate-limiting step in the metal oxide-catalyzed ozonation process based on single-site redox,which inhibits the activity,greatly limits the practical application of the multiphase catalytic ozonation technology. To solve this bottleneck problem,lattice doping of metal oxide γ-Al_(2)O_(3) substrates with transition metal species Fe and Ti was used to prepare novel dual reaction center catalysts( FT-A-1 DRCs). Characterization of their morphological structures and chemical compositions was conducted by XRD,TEM,XPS,and other techniques,and it was demonstrated that the lattice substitution of Fe and Ti for Al resulted in the formation of surface-poor electron-rich microregions( electron-rich Fe microcenters and electron-deficient Ti microcenters). The FT-A-1 DRCs were used to catalyze the odor oxidation process and exhibited excellent activity and stability for the removal of a range of non-degradable organic pollutants,such as ibuprofen. The interfacial reaction mechanism was revealed using EPR and electrochemical techniques. It was found that in the catalytic odor oxidation process, O_(3)/H_(2)O was directionally reduced at the electron-rich microcenters to produce ·OH,whereas the contaminants could be oxidized at the electron-deficient microcenters as electron donors to continuously supply electrons to the reaction system. This reaction process utilizes the pollutant’s own energy to achieve two-way degradation of the pollutant( ·OH attack and direct electron donor),thereby overcoming the rate-limiting step in the metal-oxidecatalyzed ozone oxidation process.
作者
张帆
宋阳
胡春
吕来
ZHANG Fan;SONG Yang;HU Chun;LYU Lai(Key Laboratory for Water Quality and Conservation of the Pearl River Delta,Ministry of Education,Institute of Environmental Research at Greater Bay,Guangzhou University,Guangzhou 510006,China;Faculty of Civil and Transportation Engineering,Guangdong University of Technology,Guangzhou 510006,China;Key Laboratory of Drinking Water Science and Technology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2021年第5期2360-2369,共10页
Environmental Science
基金
国家自然科学基金青年科学基金项目(51808140)
国家自然科学基金重点项目(51838005)。
关键词
污染物供电子
催化臭氧化
双反应中心
铁钛共掺杂
表面电子转移
electron donation of pollutants
catalytic odor oxidation
dual reaction center
Fe-Ti co-doping
surface electron transfer
