Potential Dependence of Volcano Plot of Oxygen Reduction Reaction: Mathematical Origin and Implications for Catalyst Design.
Potential Dependence of Volcano Plot of Oxygen Reduction Reaction: Mathematical Origin and Implications for Catalyst Design.
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DOI：
10.1021/acs.jpclett.9b02436
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发表时间：
2019-10
期刊：
影响因子：
--
通讯作者：
Yufan Zhang;Jianbo Zhang;Jun Huang
中科院分区：
文献类型：
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作者：
Yufan Zhang;Jianbo Zhang;Jun Huang
Climbing up to the volcano peak stands as a challenging problem for oxygen reduction. Repeated efforts have been put into fine-tuning the binding energy of oxygen reaction intermediates within a narrow region of 0.2 eV by adjusting the catalyst electronic structure. Herein, we address ourselves to two different, oft-neglected but non-trivial problems: (a) does a superior ORR catalyst in rotating disk electrode (RDE) experiments still work well, usually at a different potential, in practical fuel cells? (b) for a given catalyst, can we place it on the volcano peak by adjusting the electrode potential (ϕ^M) which can be easily varied within 0.5 V in experiments, and the potential at the reaction plane in solution (ϕ^OHP) which is modulated by double layer electrostatic effects? To answer these two problems, we articulate mathematical origin of the volcano plot and reveal its dependence on ϕ^M and ϕ^OHP, by combining a microkinetic model for oxygen reduction reaction and a mean-field model for the double layer. Furthermore, we explore possible approaches of adjusting ϕ^OHP, for instance, by varying electrolyte concentration, and particularly, by tuning the electrostatic properties of the support material in a supported catalyst system. The investigation of how electrostatic properties of the support material affect the volcano plot of supported catalyst opens an additional channel of catalyst-support interactions.
