发表机构
School of Materials and Chemical Technology, Institute of Science Tokyo; RIKEN Center for Computational Science; Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada（东京科学大学材料化学技术学院; 理化学研究所计算科学中心; 加查马达大学数学与自然科学学院化学系）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过DFTB-FF混合方法调控ZrO2纳米颗粒能带结构，发现化学计量比可设计电子结构，富Zr纳米颗粒的低配位位点激活CO的C-O键，从而调控吸附活性。
AI 中文摘要
我们提出了一项结合密度泛函理论（DFT）和密度泛函紧束缚（DFTB）方法的研究，针对实验相关尺寸（几纳米）的氧化锆（ZrO2）纳米颗粒及其与CO分子的相互作用。我们开发了一种混合DFTB-力场（DFTB-FF）框架，其中能带结构计算依赖于现有的Slater-Koster框架，而结构优化和吸附性质的准确性则通过在DFTB中引入经典的长程原子间势（取代传统的排斥势）来控制。此外，引入了配位依赖的Zr-C势，以考虑体相类晶面位点与欠配位的尖端和边缘位点不同的局部化学环境，从而改进对CO吸附的描述。这种混合DFTB-FF方法显著提高了几何优化的稳健性，并为将DFTB的应用扩展到复杂氧化物纳米结构提供了一种实用策略。计算表明，终止化学计量比可用于设计本征、p型或n型电子结构，从而调节氧化锆纳米颗粒的吸附活性。虽然化学计量比的纳米颗粒不会激活C-O键，但富Zr（n型）纳米颗粒中的低配位位点表现出化学吸附，伴随电荷向CO反键LUMO衍生轨道捐赠，导致C-O键激活。这些结果表明，由化学计量比控制的电子结构和纳米结构化引入的欠配位表面位点在控制氧化锆纳米颗粒的吸附强度和反应活性中起着关键作用。
英文摘要
We present a combined density functional theory (DFT) and density functional tight binding (DFTB) study of zirconia (ZrO2) nanoparticles of experimentally relevant sizes of several nanometers and their interactions with the CO molecule. A hybrid DFTB - Force Field (DFTB-FF) framework is developed, whereby band structure calculations rely on an existing Slater-Koster framework, while the accuracy of structural optimization and adsorption properties is controlled by the introduction of classical long-range interatomic potentials into DFTB instead of the traditional repulsive potentials. Additionally, coordination-dependent Zr-C potentials are introduced to account for the distinct local chemical environments of bulk-like facet sites and under-coordinated tip and edge sites, thereby improving the description of CO adsorption. This hybrid DFTB-FF approach substantially improves the robustness of geometry optimization and provides a practical strategy for extending the applicability of DFTB to complex oxide nanostructures. The calculations reveal that termination stoichiometry can be used to engineer intrinsic, p-type, or n-type electronic structures and thereby tune the adsorption activity of zirconia nanoparticles. While stoichiometric nanoparticles do not activate the C-O bond, low-coordinated sites in Zr-rich (n-type) nanoparticles exhibit chemisorption accompanied by charge donation into a CO antibonding LUMO-derived orbital, resulting in C-O bond activation. These results demonstrate that stoichiometry-controlled electronic structure and under-coordinated surface sites introduced by nanostructuring play a key role in governing the adsorption strength and reactivity of zirconia nanoparticles.
