Analytische Chemie-Zentrum für Elektrochemie (CES), Ruhr-Universität Bochum, NC04/788, 44780 Bochum (Germany) http://www.rub.de/elan.
Angew Chem Int Ed Engl. 2014 Aug 4;53(32):8508-12. doi: 10.1002/anie.201402710. Epub 2014 Jun 27.
Reversible interconversion of water into H2 and O2, and the recombination of H2 and O2 to H2O thereby harnessing the energy of the reaction provides a completely green cycle for sustainable energy conversion and storage. The realization of this goal is however hampered by the lack of efficient catalysts for water splitting and oxygen reduction. We report exceptionally active bifunctional catalysts for oxygen electrodes comprising Mn3O4 and Co3O4 nanoparticles embedded in nitrogen-doped carbon, obtained by selective pyrolysis and subsequent mild calcination of manganese and cobalt N4 macrocyclic complexes. Intimate interaction was observed between the metals and nitrogen suggesting residual M-N(x) coordination in the catalysts. The catalysts afford remarkably lower reversible overpotentials in KOH (0.1 M) than those for RuO2, IrO2, Pt, NiO, Mn3O4, and Co3O4, thus placing them among the best non-precious-metal catalysts for reversible oxygen electrodes reported to date.
水可逆地转化为 H2 和 O2，并且 H2 和 O2 重新组合为 H2O，从而利用反应的能量，为可持续能源的转换和存储提供了一个完全绿色的循环。然而，缺乏高效的水分解和氧还原催化剂阻碍了这一目标的实现。我们报告了一种由嵌入氮掺杂碳中的 Mn3O4 和 Co3O4 纳米粒子组成的用于氧电极的异常活性的双功能催化剂，该催化剂通过锰和钴 N4 大环配合物的选择性热解和随后的温和煅烧获得。在金属和氮之间观察到了紧密的相互作用，表明在催化剂中存在残留的 M-N(x)配位。与 RuO2、IrO2、Pt、NiO、Mn3O4 和 Co3O4 相比，该催化剂在 KOH（0.1 M）中的可逆过电势明显更低，因此将其列为迄今为止报道的用于可逆氧电极的最佳非贵金属催化剂之一。
