Department of Chemical Physics & Hefei National Laboratory for Physical Sciences at the Microscale, iChEM, University of Science and Technology of China, Hefei, Anhui, 230026, China.
Hefei National Laboratory for Physical Sciences at the Microscale, and Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China.
Angew Chem Int Ed Engl. 2017 Dec 4;56(49):15617-15621. doi: 10.1002/anie.201708825. Epub 2017 Nov 14.
The electrocatalytic reduction reaction of carbon dioxide can be significantly enhanced by the use of a sharp-tip electrode. However, the experimentally observed rate enhancement is many orders of magnitudes smaller than what would be expected from an energetic point of view. The kinetics of this tip-enhanced reaction are shown to play a decisive role, and a novel reaction-diffusion kinetic model is proposed. The experimentally observed sharp-tip enhanced reaction and the maximal producing rate of carbon monoxide under different electrode potentials are well-reproduced. Moreover, the optimal performance shows a strong dependence on the interaction between CO and the local electric field, on the adsorption rate of CO , but not on the reaction barrier. Two new strategies to further enhance the reaction rate have also been proposed. The findings highlight the importance of kinetics in modeling electrocatalytic reactions.
二氧化碳的电催化还原反应可以通过使用尖端电极得到显著增强。然而，从能量的角度来看，实验观察到的速率增强幅度要小几个数量级。实验表明，这种尖端增强反应的动力学起着决定性的作用，并提出了一种新的反应-扩散动力学模型。该模型很好地再现了实验观察到的尖端增强反应和在不同电极电势下一氧化碳的最大生成速率。此外，最佳性能强烈依赖于 CO 与局部电场之间的相互作用、CO 的吸附速率，但与反应势垒无关。还提出了两种进一步提高反应速率的新策略。这些发现强调了动力学在电催化反应建模中的重要性。
