The electrocatalytic activity of metallic nanostructures is commonly tuned by changing their structure, composition, size and morphology to decrease the activation energy of a rate-determining elementary step. Here, we report that the electrocatalytic activity of the excited plasmonic model Pd nanostructured electrocatalyst for oxygen reduction reaction (ORR) can be enhanced significantly by increasing the kinetic pre-exponential factor. The localized surface plasmon resonance (SPR) effect promotes a two-orders of magnitude increase in the apparent pre-exponential factor in the Arrhenius equation. Combined experimental and theoretical analyses of the kinetic H/D isotope effect indicate that the observed increase in the apparent pre-exponential factor is attributable to an increased quantum–mechanical proton tunneling arising from the local electric field enhancement upon SPR excitation. Intriguingly, the ORR activity enhancement can be observed under simulated solar light illumination, implying potential for fuel cell applications. The methodology developed in this study is applicable to other proton-coupled electron-transfer reactions, thus opening a promising route to manipulating electrocatalytic reactivity by tuning the kinetic pre-exponential factor and suggesting potential for fuel cell applications.

金属纳米结构的电催化活性通常通过改变其结构，组成，大小和形态来进行调节，以降低决定速率的基本步骤的活化能。在这里，我们报告说，通过增加动力学预指数因子，可以显着提高激发的等离激元模型Pd纳米结构的电催化剂对氧还原反应（ORR）的电催化活性。局部表面等离振子共振（SPR）效应促进了Arrhenius方程中表观前指数因子的数量级增加了两个数量级。动力学H / D同位素效应的组合实验和理论分析表明，观察到的表观前指数因子的增加归因于SPR激发时局部电场增强引起的量子力学质子隧穿的增加。有趣的是，可以在模拟的太阳光照射下观察到ORR活性的增强，这暗示了燃料电池应用的潜力。这项研究中开发的方法学适用于其他质子偶联的电子转移反应，从而通过调节动力学指数前因子开辟了一条有希望的途径来操纵电催化反应性，并暗示了燃料电池应用的潜力。在模拟太阳光照射下可以观察到ORR活性增强，这暗示了燃料电池应用的潜力。这项研究中开发的方法学适用于其他质子偶联的电子转移反应，从而通过调节动力学指数前因子开辟了一条有希望的途径来操纵电催化反应性，并暗示了燃料电池应用的潜力。在模拟太阳光照射下可以观察到ORR活性增强，这暗示了燃料电池应用的潜力。这项研究中开发的方法学适用于其他质子偶联的电子转移反应，从而通过调节动力学指数前因子开辟了一条有希望的途径来操纵电催化反应性，并暗示了燃料电池应用的潜力。