Song Kun-Ting, Zagalskaya Alexandra, Schott Christian M, Schneider Peter M, Garlyyev Batyr, Alexandrov Vitaly, Bandarenka Aliaksandr S
Physik-Department ECS, Technische Universität München, James-Franck-Str. 1, Garching D-85748, Germany.
Department of Chemical and Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States.
J Phys Chem C Nanomater Interfaces. 2024 Mar 18;128(12):4969-4977. doi: 10.1021/acs.jpcc.4c00531. eCollection 2024 Mar 28.
Electrolyte species can significantly influence the electrocatalytic performance. In this work, we investigate the impact of alkali metal cations on the oxygen reduction reaction (ORR) on active PtGd and PtY polycrystalline electrodes. Due to the strain effects, Pt alloys exhibit a higher kinetic current density of ORR than pure Pt electrodes in acidic media. In alkaline solutions, the kinetic current density of ORR for Pt alloys decreases linearly with the decreasing hydration energy in the order of Li > Na > K > Rb > Cs, whereas Pt shows the opposite trend. To gain further insights into these experimental results, we conduct complementary density functional theory calculations considering the effects of both electrode surface strain and electrolyte chemistry. The computational results reveal that the different trends in the ORR activity in alkaline media can be explained by the change in the adsorption energy of reaction intermediates with applied surface strain in the presence of alkali metal cations. Our findings provide important insights into the effects of the electrolyte and the strain conditions on the electrocatalytic performance and thus offer valuable guidelines for optimizing Pt-based electrocatalysts.
电解质种类会显著影响电催化性能。在本工作中，我们研究了碱金属阳离子对活性PtGd和PtY多晶电极上氧还原反应（ORR）的影响。由于应变效应，在酸性介质中，铂合金表现出比纯铂电极更高的ORR动力学电流密度。在碱性溶液中，铂合金的ORR动力学电流密度随着水合能的降低呈线性下降，顺序为Li > Na > K > Rb > Cs，而铂则呈现相反的趋势。为了进一步深入了解这些实验结果，我们进行了考虑电极表面应变和电解质化学效应的互补密度泛函理论计算。计算结果表明，碱性介质中ORR活性的不同趋势可以通过在碱金属阳离子存在下，反应中间体吸附能随施加的表面应变的变化来解释。我们的研究结果为电解质和应变条件对电催化性能的影响提供了重要见解，从而为优化铂基电催化剂提供了有价值的指导。
