(623f) Understanding the Influence of Microenvironment on Electrocatalysis Via Single Nanoparticle Electrochemistry

The significance of microenvironment in tuning the electrocatalytic reactivity and selectivity has been recognized in recent years [1]. Combining experiment with simulation, we proposed a novel approach to explore and determine reaction mechanisms for various microenvironment modifiers.

Selective electrochemical production of valued chemicals is significant but remains a great challenge in chemistry. Conventional approaches for enhancing reaction selectivity focus on the improvement of the catalysts themselves. We systematically studied the reaction kinetics and mass transport behavior of LaNiO₃ nanocubes catalyzed hydrogen peroxide reduction reaction (HPRR) at ensemble and single nanoparticle levels using nano-impact electrochemistry [2]. We find that the selectivity of HPRR was altered at individual random-walk nanoparticles as compared to their ensemble counterpart without changing the reaction kinetics, due to the significantly enhanced mass transport at single nanoparticles (Figure 1a). This discovery offers the scope of new catalytic approaches for engineering electrochemical reactions in general.

Plasmon-enhanced electrochemistry (PEEC) has been observed to facilitate energy conversion systems by converting light energy to chemical energy. However, comprehensively understanding the PEEC mechanism remains challenging due to the predominant use of ensemble-based methodologies on macroscopic electrodes, which fails to measure electron-transfer kinetics due to constraints from mass transport and the averaging effect. In this study, we have employed nanoparticle impact electrochemistry measuring electrochemical dynamics at a single-nanoparticle level under optimal mass transport conditions, along with microscopic electron-transfer theory for data interpretation [3]. By investigating the plasmon enhanced hydrogen evolution reaction at individual silver nanoparticles, we have clearly revealed the previously unknown influence of solvent effects within the PEEC mechanism (Figure 1b). This finding suggests an additional approach to optimize plasmon-assisted electrocatalysis and electrosynthesis systems.

References:

[1] ACS Energy Lett. 2023, 8, 9, 3935

[2] Angew. Chem. Int. Ed. 2022, 61, e202207270

[3] Nano Lett. 2023, 23, 23, 10871