Boosting the oxygen reduction activity on metal surfaces by fine-tuning interfacial water with midinfrared stimulation

Public summary

* Interfacial water on the metal surface acts as a physical barrier preventing efficient catalytic performance.

* The MIRS technique is a novel method for fine-tuning interfacial water structures.

* The application of an appropriate MIRS results in a 50-fold increase in the oxygen reduction activity.

* MIRS can provide a new approach for promoting catalysis and energy conversion and development of photodoped nanofluidic devices.

Abstract

Heterogeneous catalysis at the metal surface generally involves the transport of molecules through the interfacial water layer to access the surface, which is a rate-determining step at the nanoscale. In this study, taking the oxygen reduction reaction on a metal electrode in aqueous solution as an example, using accurate molecular dynamic simulations, we propose a novel long-range regulation strategy in which midinfrared stimulation (MIRS) with a frequency of approximately 1,000 cm−1 is applied to nonthermally induce the structural transition of interfacial water from an ordered to disordered state, facilitating the access of oxygen molecules to metal surfaces at room temperature and increasing the oxygen reduction activity 50-fold. Impressively, the theoretical prediction is confirmed by the experimental observation of a significant discharge voltage increase in zinc-air batteries under MIRS. This MIRS approach can be seamlessly integrated into existing strategies, offering a new approach for accelerating heterogeneous reactions and gas sensing within the interfacial water system.