Physical Biosciences Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720.
1] Physical Biosciences Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720 [2].
Nat Chem. 2014 Apr;6(4):362-7. doi: 10.1038/nchem.1874. Epub 2014 Feb 23.
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.
在任何人工光合作用系统中，将水氧化为氧气提供了用于将质子或二氧化碳还原为燃料所需的电子。详细了解这个四电子反应的工作原理对于开发由丰富的地球材料（如第一过渡金属氧化物）制成的改进型、稳健的催化剂非常重要。在这里，我们使用时间分辨傅里叶变换红外光谱并在反应条件下，鉴定了丰富的金属氧化物催化剂钴氧化物（Co3O4）催化的水氧化反应的中间产物。一个中间产物是表面超氧化物（吸收在 1013 cm(-1)处的三电子氧化中间产物），而观察到的第二个中间产物归因于氧合 Co(IV)位（吸收在 840 cm(-1)处的单电子氧化中间产物）。中间产物的时间行为表明它们属于不同的催化位点。表面中间产物的结构和动力学知识将使设计更有效的水氧化催化的改进型金属氧化物材料成为可能。
