Zhang Biaobiao, Daniel Quentin, Fan Lizhou, Liu Tianqi, Meng Qijun, Sun Licheng
Department of Chemistry, KTH Royal Institute of Technology, Stockholm 10044, Sweden.
Department of Chemistry, KTH Royal Institute of Technology, Stockholm 10044, Sweden; State Key Laboratory of Fine Chemicals, Institute of Artificial Photosynthesis, DUT-KTH Joint Education and Research Center on Molecular Devices, Dalian University of Technology (DUT), Dalian 116024, P. R. China.
iScience. 2018 Jun 29;4:144-152. doi: 10.1016/j.isci.2018.05.018. Epub 2018 May 30.
Identifying surface active intermediate species is essential to reveal the catalytic mechanism of water oxidation by metal-oxides-based catalysts and to develop more efficient catalysts for oxygen-oxygen bond formation. Here we report, through electrochemical methods and ex situ infrared spectroscopy, the identification of a Mn = O intermediate during catalytic water oxidation by a c-disordered δ-MnO with an onset-potential-dependent reduction peak at 0.93 V and an infrared peak at 912 cm. This intermediate is proved to be highly reactive and much more oxidative than permanganate ion. Therefore, we propose a new catalytic mechanism for water oxidation catalyzed by Mn oxides, with involvement of the Mn = O intermediate in a resting state and the Mn-O-Mn = O as a real active species for oxygen-oxygen bond formation.
识别表面活性中间体对于揭示基于金属氧化物的催化剂催化水氧化的机理以及开发更高效的氧-氧键形成催化剂至关重要。在此，我们通过电化学方法和非原位红外光谱，报道了在由c-无序δ-MnO催化水氧化过程中鉴定出一种Mn = O中间体，其起始电位依赖性还原峰在0.93 V，红外峰在912 cm。该中间体被证明具有高反应活性且氧化性比高锰酸根离子强得多。因此，我们提出了一种由锰氧化物催化水氧化的新催化机理，其中Mn = O中间体处于静止状态，而Mn-O-Mn = O作为氧-氧键形成的真正活性物种。
