In their Comment (X. Yin, E. F. Holby and P. Zelenay, Energy Environ. Sci., the comment.) entitled “Kinetic degradation models of Fe–N–C electrocatalysts for the oxygen reduction reaction (ORR) and mechanistic implications”, Yin, Holby and Zelenay declared that the INRS model, analyzing and interpreting the instability of our NC_Ar + NH₃ highly active, high performance, but unstable Fe/N/C catalyst in a PEM fuel cell, contains several essential misconceptions that weaken the validity of the conclusions regarding the degradation mechanisms that we might draw from our model. In particular, they address two main issues that they believe are not valid: (i) the inclusion of non-kinetic effects in kinetic modeling, which, according to them, will prevent us from obtaining true kinetic information about the loss of FeN₄ active sites when the decay of the current density of the catalyst is measured at 0.6 V in PEM fuel cells; and (ii) inconsistencies in the thermodynamics underpinning the proposed degradation mechanisms. Here, according to their Comment, the cohesion energy of bulk (metal) iron would be disregarded in our thermodynamic calculations of the demetallation equilibrium constant (K_c) of FeN₄ sites in the acid medium of PEM fuel cells. This would lead us to false conclusions about the K_c values determined for all FeN₄ demetallation reactions that were considered in our model. Four of our recent publications are targeted in this Comment: two main ones, published in Energy Environ. Sci., 2018, 11, 365–382, and 2019, 12, 3015–3037; and two satellite ones, published in J. Electrochemical Society, 2017, 164, F948–F957 and 2019, 166, F3277–F3286. In this reply to their comment, we demonstrate that the conclusions drawn in the four targeted publications remain valid and that the arguments expressed in the Comment are unfounded. The fast decay in PEM fuel cells of a highly active, high performance, but unstable Fe/N/C catalyst like our NC_Ar + NH₃ does not follow an electrochemical but a chemical mechanism which is governed (in conjunction with Le Chatelier's principle) by the thermodynamic equilibrium constant (K_c) of the demetallation reaction of its ORR active FeN₄ sites in the catalyst micropores.

中文翻译：

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Xi Yin，Edward Environ的“关于“用于PEM燃料电池的非PGM电催化剂：氟化对高活性NC_Ar + NH3催化剂的活性和稳定性的影响”的评论”答复。科学，10.1039 / D0EE02069A

在他们的评论（X. Yin，EF Holby和P. Zelenay，Energy Environ。Sci。，评论）中，标题为“ Fe- NC催化剂对氧还原反应（ORR）的动力学降解模型及其机理”， Yin，Holby和Zelenay宣布采用INRS模型，分析并解释了我们的NC_Ar + NH ₃的不稳定性PEM燃料电池中的高活性，高性能但不稳定的Fe / N / C催化剂包含一些基本的误解，这些误解削弱了我们可能从模型中得出的有关降解机理的结论的有效性。特别是，他们解决了他们认为无效的两个主要问题：（i）在动力学建模中包含非动力学效应，据他们所述，这将阻止我们获得有关FeN ₄损失的真实动力学信息。在PEM燃料电池中在0.6 V处测量催化剂的电流密度衰减时的活性位；（ii）提出的降解机理的热力学不一致。在这里，根据他们的评论，在我们对PEM燃料电池酸性介质中FeN ₄位的脱金属平衡常数（K _c）进行热力学计算时，将不考虑大块（金属）铁的内聚能。这将导致我们得出关于在模型中考虑的所有FeN ₄脱金属反应的K _c值的错误结论。本注释针对的是我们最近的四本出版物：《能源环境》中的两本主要出版物。科学，2018，11，365-382，和2019年，12，3015-3037; 以及两颗卫星，分别发表在《J.电化学学会》，2017年，第164页，F948-F957和2019年，第166页，F3277-F3286中。在对他们的评论的答复中，我们证明了在四个有针对性的出版物中得出的结论仍然有效，并且评论中表达的论点是没有根据的。高活性，高性能但不稳定的Fe / N / C催化剂（如我们的NC_Ar + NH _3）在PEM燃料电池中的快速衰变并不遵循电化学原理，而是遵循化学机理（由Le Chatelier原理决定）热力学平衡常数（K _c催化剂微孔中ORR活性FeN ₄位点的脱金属反应）