“蜜蜂工作模式”动态单原子催化剂设计在CO催化氧化中应用的多尺度计算模拟研究

It has attracted much attention of scientists of physics, chemistry, and material science for design of highly efficient and economic single-atom catalyst (SAC), and the bottleneck of this field is how to figure out an efficient method in avoiding sintering of the SAC during the chemical reactions. In this project, to conquer such a big issue, we proposed a conceptually innovative Bee-Working dynamic single-atom catalyst (BWD-SAC). Specifically, upon the adsorption of the reactants during the chemical reaction process, the noble (transition) metal nanoparticles will be highly dispersed into single atoms. On such single-atom active sites, chemical reactions occur highly efficiently, just like a bee works individually. Once the chemical activities are finished, these single atoms either stay there solidly or re-forming into nanoclusters or nanoparticles, and then continue the next cycles. Here, taking CO oxidation as a prototypical example, we adopt multiscale computational simulations to investigate such a project. Our central aim is to figure out the effective approach in successfully design such BWD-SAC, via doping or applying external strain to modulate the metal (nanoparticles)-substrate interactions, and addressing the effect of the adsorption of reactants molecules during the chemical processes on the relative stability between nanoparticle and separated single-atom phases. Particularly, we’d like to illuminate the underlying driving force of BWD-SAC system and to identify such an amazing catalytic mechanism. The present proposal is expected to provide valuable guidance in highly efficient catalyst design for vehicle emission reduction and other chemical reactions involved in as well.

如何避免单原子催化剂在化学反应过程中因烧结聚合成纳米颗粒从而失去其内禀优势是物理、化学、材料等科研领域发展新一代经济高效催化剂的瓶颈问题。该课题拟创新性地设计一种“蜜蜂工作模式动态单原子催化剂（BWD-SAC）”：催化反应过程中贵金属颗粒中的原子倾巢而出，高度分散到单原子量级，每个原子像单个蜜蜂采蜜一样高效工作；反应产物脱附后，催化剂以单原子形式存在或趋向于形成纳米颗粒或团簇，即回巢。该项目拟以汽车尾气主要成分CO的催化氧化为例，采用多尺度模拟计算通过掺杂、应力等方法调控纳米颗粒（单原子）催化剂与衬底之间的电子相互作用，并研究反应物的吸附对沉积在衬底上的催化剂原子形成聚合的团簇相与形成分散的单原子相的相对稳定性的影响规律，重点阐明能够实现BWD-SAC体系的内禀驱动力及其催化机理。该项目的实施有望克服单原子催化剂由于聚合长大活性失效这一普遍难题，为下一代经济、高效催化剂制备提供理论指导。

单原子催化剂在化学反应过程中因烧结聚合成纳米颗粒从而失去其内禀优势是物理、化学、材料等科研领域发展新一代经济高效催化剂的瓶颈问题。该项目采用第一性原理计算为主的多尺度模拟计算方法，以汽车尾气主要成分 CO 的高效催化氧化为主要研究对象，研究体系范围从有缺陷衬底到无缺陷衬底，从施加理论应力到构筑内秉应力的异质结体系，通过调控贵金属（过渡族）金属原子和衬底的相互作用，阐明了单原子催化剂和这些衬底的相互作用、稳定性和催化活性的选择定则，提出了单原子催化剂体系中单原子之间的电荷、应力等协同催化机制，从理论上筛选出一系列物美价廉的高分散、高负载率、高效的单原子催化剂体系。相关研究成果在包括Adv. Sci.、Adv. Mater.、J. Mater. Chem. A、 ACS Nano、Nanoscale、ACS Appl. Mater. Inter.、Chem.Com.、Phys. Rev. B 等国内外主流期刊上发表相关高水平学术论文 11篇。作为主要完成人获得河南省自然科学二等奖一项。