Molecular metal-Nx centres in porous carbon for electrocatalytic hydrogen evolution.
Molecular metal-Nx centres in porous carbon for electrocatalytic hydrogen evolution.
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DOI：
10.1038/ncomms8992
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发表时间：
2015-08-07
影响因子：
16.6
通讯作者：
Müllen K
中科院分区：
文献类型：
--
作者：
Liang HW;Brüller S;Dong R;Zhang J;Feng X;Müllen K
用高效、低成本的催化剂替代贵金属铂，在低过电位下进行电催化析氢，对清洁能源装置具有巨大的前景。在这里，我们报告了一种新型的强大的钴-氮/碳催化剂的析氢反应（HER），这是通过热解的钴-N4大环或钴/邻苯二胺复合材料，并使用二氧化硅胶体作为硬模板。我们将碳载体上分散良好的分子CoNx位点确定为负责HER的活性位点。CoNx/C催化剂在酸中每个钴位点表现出极高的转换频率，例如，在100和200 mV的过电位下分别为0.39和6.5 s-1，这高于其他可扩展的非贵金属HER催化剂的报道。我们的研究结果表明，开发新的非贵金属HER催化剂家族的基础上，通过经济上可扩展的协议的控制转化均匀的金属络合物到固态碳催化剂的巨大希望。从水中析氢有望成为未来的清洁能源，然而，高效率所必需的贵金属催化剂的成本非常昂贵。在这里，作者制造了一种多孔钴-氮/碳催化剂，它可以提供高活性和稳定性，但成本降低。
Replacement of precious platinum with efficient and low-cost catalysts for electrocatalytic hydrogen evolution at low overpotentials holds tremendous promise for clean energy devices. Here we report a novel type of robust cobalt–nitrogen/carbon catalyst for the hydrogen evolution reaction (HER) that is prepared by the pyrolysis of cobalt–N4 macrocycles or cobalt/o-phenylenediamine composites and using silica colloids as a hard template. We identify the well-dispersed molecular CoNx sites on the carbon support as the active sites responsible for the HER. The CoNx/C catalyst exhibits extremely high turnover frequencies per cobalt site in acids, for example, 0.39 and 6.5 s−1 at an overpotential of 100 and 200 mV, respectively, which are higher than those reported for other scalable non-precious metal HER catalysts. Our results suggest the great promise of developing new families of non-precious metal HER catalysts based on the controlled conversion of homogeneous metal complexes into solid-state carbon catalysts via economically scalable protocols. Hydrogen evolution from water promises a future clean energy source, however the cost of noble metal catalysts, which are necessary for high efficiency, are very expensive. Here, the authors fabricate a porous cobalt–nitrogen/carbon catalyst which can deliver high activity and stability but at reduced cost.