Department of Chemistry, Indian Institute of Science Education and Research, Pune, 411008 India.
Department of Chemistry, Indian Institute of Science Education and Research, Pune, 411008 India;
Proc Natl Acad Sci U S A. 2022 Jan 18;119(3). doi: 10.1073/pnas.2115135119.
Catalysis is a method of accelerating chemical reactions that is critically important for fundamental research as well as for industrial applications. It has been recently discovered that catalytic reactions on metal nanoparticles exhibit cooperative effects. The mechanism of these observations, however, remains not well understood. In this work, we present a theoretical investigation on possible microscopic origin of cooperative communications in nanocatalysts. In our approach, the main role is played by positively charged holes on metal surfaces. A corresponding discrete-state stochastic model for the dynamics of holes is developed and explicitly solved. It is shown that the observed spatial correlation lengths are given by the average distances migrated by the holes before they disappear, while the temporal memory is determined by their lifetimes. Our theoretical approach is able to explain the universality of cooperative communications as well as the effect of external electric fields. Theoretical predictions are in agreement with experimental observations. The proposed theoretical framework quantitatively clarifies some important aspects of the microscopic mechanisms of heterogeneous catalysis.
催化是一种加速化学反应的方法，对于基础研究和工业应用都至关重要。最近发现，金属纳米粒子上的催化反应表现出协同效应。然而，这些观察结果的机制仍未得到很好的理解。在这项工作中，我们提出了一种关于纳米催化剂中协同通信可能微观起源的理论研究。在我们的方法中，金属表面上的正电荷空穴起着主要作用。为此，我们开发了一个空穴动力学的离散态随机模型，并对其进行了显式求解。结果表明，观察到的空间相关长度由空穴在消失之前迁移的平均距离给出，而时间记忆则由它们的寿命决定。我们的理论方法能够解释协同通信的普遍性以及外电场的影响。理论预测与实验观察结果一致。所提出的理论框架定量地阐明了多相催化中微观机制的一些重要方面。
