Time-resolved observations of water oxidation intermediates on a cobalt oxide nanoparticle catalyst
Time-resolved observations of water oxidation intermediates on a cobalt oxide nanoparticle catalyst
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DOI：
10.1038/nchem.1874
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发表时间：
2014-04-01
期刊：
影响因子：
21.8
通讯作者：
Frei, Heinz
中科院分区：
文献类型：
--
作者：
Zhang, Miao;de Respinis, Moreno;Frei, Heinz
在任何人工光合系统中，水氧化为分子氧提供了质子或二氧化碳还原为燃料所需的电子。详细了解这种四电子反应是如何工作的，对于开发由地球上丰富的材料（如第一排过渡金属氧化物）制成的改进的强效催化剂非常重要。本文利用时间分辨傅立叶变换红外光谱，在反应条件下，鉴定了由丰富的金属氧化物催化剂氧化钴（Co3O4）催化的水氧化中间体。一个中间体是表面超氧化物（三电子氧化中间体在1013厘米（-1）处吸收），而第二个观察到的中间体归因于氧Co（IV）位点（单电子氧化中间体在840厘米（-1）处吸收）。中间体的时间行为表明它们属于不同的催化位点。了解表面中间体的结构和动力学将有助于设计出更有效的水氧化催化的金属氧化物材料。
In any artificial photosynthetic system, the oxidation of water to molecular oxygen provides the electrons needed for the reduction of protons or carbon dioxide to a fuel. Understanding how this four-electron reaction works in detail is important for the development of improved robust catalysts made of Earth-abundant materials, like first-row transition-metal oxides. Here, using time-resolved Fourier-transform infrared spectroscopy and under reaction conditions, we identify intermediates of water oxidation catalysed by an abundant metal-oxide catalyst, cobalt oxide (Co3O4). One intermediate is a surface superoxide (three-electron oxidation intermediate absorbing at 1,013 cm(-1)), whereas a second observed intermediate is attributed to an oxo Co(IV) site (one-electron oxidation intermediate absorbing at 840 cm(-1)). The temporal behaviour of the intermediates reveals that they belong to different catalytic sites. Knowledge of the structure and kinetics of surface intermediates will enable the design of improved metal-oxide materials for more efficient water oxidation catalysis.