Mechanistic Investigation of Water Oxidation Catalyzed by Uniform, Assembled MnO Nanoparticles

详细信息    查看全文

• 作者：Kyoungsuk Jin ; Hongmin Seo ; Toru Hayashi ; Mani Balamurugan ; Donghyuk JeongYoo Kyung Go ; Jung Sug Hong ; Kang Hee Cho ; Hirotaka Kakizaki ; Nadège Bonnet-Mercier ; Min Gyu Kim ; Sun Hee Kim ; Ryuhei NakamuraKi Tae Nam
• 刊名：Journal of the American Chemical Society
• 出版年：2017
• 出版时间：February 15, 2017
• 年：2017
• 卷：139
• 期：6
• 页码：2277-2285
• 全文大小：757K
• ISSN：1520-5126

文摘

The development of active water oxidation catalysts is critical to achieve high efficiency in overall water splitting. Recently, sub-10 nm-sized monodispersed partially oxidized manganese oxide nanoparticles were shown to exhibit not only superior catalytic performance for oxygen evolution, but also unique electrokinetics, as compared to their bulk counterparts. In the present work, the water-oxidizing mechanism of partially oxidized MnO nanoparticles was investigated using integrated in situ spectroscopic and electrokinetic analyses. We successfully demonstrated that, in contrast to previously reported manganese (Mn)-based catalysts, Mn(III) species are stably generated on the surface of MnO nanoparticles via a proton-coupled electron transfer pathway. Furthermore, we confirmed as to MnO nanoparticles that the one-electron oxidation step from Mn(II) to Mn(III) is no longer the rate-determining step for water oxidation and that Mn(IV)═O species are generated as reaction intermediates during catalysis.