Boron-doped graphene as active electrocatalyst for oxygen reduction reaction at a fuel-cell cathode
Boron-doped graphene as active electrocatalyst for oxygen reduction reaction at a fuel-cell cathode
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DOI：
10.1016/j.jcat.2014.07.024
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发表时间：
2014-10-01
影响因子：
7.3
通讯作者：
Di Valentin, Cristiana
中科院分区：
文献类型：
--
作者：
Fazio, Gianluca;Ferrighi, Lara;Di Valentin, Cristiana
据报道，在0.035 V的起始电位下，硼掺杂石墨烯是氧还原反应（ORR）的最佳非金属掺杂石墨烯电催化剂（Jiao etal ., 2014）。在目前的DFT研究中，沿可能的反应途径确定了中间体和过渡结构。讨论了Langmuir-Hinschelwood机制和ley- ideal机制。分子氧与带正电的B原子结合，形成一个开壳层的端对二氧中间体。联想路径比解离路径更受青睐。在酸性和碱性条件下，用Norskov和co.（2004）的方法研究了四个还原步骤的自由能图。用Pourbaix图分析了pH值对还原中间体稳定性的影响。在pH = 14时，我们计算了U = 0.05 V时电化学ORR的起始电位值，与碱性条件下的实验值比较吻合。(C) 2014爱思唯尔公司版权所有。
Boron-doped graphene was reported to be the best non-metal doped graphene electrocatalyst for the oxygen reduction reaction (ORR) working at an onset potential of 0.035 V (Jiao et al., 2014). In the present DFT study, intermediates and transition structures along the possible reaction pathways are determined. Both Langmuir-Hinschelwood and Eley-Rideal mechanisms are discussed. Molecular oxygen binds the positively charged B atom and forms an open shell end-on dioxygen intermediate. The associative path is favored with respect to the dissociative one. The free energy diagrams along the four-reduction steps are investigated with the methodology by Norskov and co. (2004) in both acidic and alkaline conditions. The pH effect on the stability of the intermediates of reduction is analyzed in terms of the Pourbaix diagram. At pH = 14, we compute an onset potential value for the electrochemical ORR of U = 0.05 V, which compares very well with the experimental value in alkaline conditions. (C) 2014 Elsevier Inc. All rights reserved.