| 杜雨庭,高登磊,张娜,伊丁,王熙.化学通报,2020,83(7):652-658. |
| 通过低熵合金实现铂金属d轨道的调控 |
| Regulation of the d-Orbitals of Platinum through Low-Entropy Alloying |
| 投稿时间：2020-02-01 修订日期：2020-03-28 |
| DOI： |
| 中文关键词: 低熵Pt-Fe合金 密度泛函理论 d轨道调控 催化 |
| 英文关键词:Low-entropy Pt-Fe alloy Density functional theory d-Orbitals regulation Catalysis |
| 基金项目:中央高校基本科研基金项目（2018JBZ107，2019RC035）、国家自然科学基金项目（91961125，21905019）、中国科学技术部“国际科技合作重点项目”（2018YFE0124600）、化学与精细化工广东省实验室项目（1932004）和北京交通大学“卓越百人”人才基金项目资助 |
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| 中文摘要: |
| 对催化剂中活性位电子结构的精准调控是实现精准催化最有效的手段之一，常见的方法包括调控晶格应力、电荷转移等。在掺杂材料体系中，人们已经运用原子晕效应等理论来解释异原子活性位几何、电子结构的改变给基底材料所带来的物理、化学性质的改变，进而实现对催化等性能的调控。本文以低熵合金为研究对象，通过第一性原理计算提出了轨道及自旋调控的新途径来尝试实现对催化的精准调控，即通过改变Pt原子的d轨道来实现对催化性能的调控。分别模拟了Pt和Pt-Fe合金在不同的吸附位点下对O2分子的吸附过程。结果发现，Fe原子的掺入在削弱表面Pt原子对O2分子吸附的情况下却没有影响其解离。通过投影态密度（PDOS）分析得到Pt-Fe合金中Fe-3d和Pt-5d轨道有较强的杂化，从而导致了Pt的d轨道发生偏移的同时产生了自旋极化现象。部分Pt的电子态移动到费米能级之上，与O2-π*产生交叠，进而导致了Pt-Fe合金中的Pt-5d与O2-π*的杂化程度明显高于纯Pt体系。理论研究表明，通过这种低熵合金的手段能够调节Pt的d轨道，从而促进对O2分子的催化效果。该研究可以预见轨道催化及自旋催化将为精准催化提供更加有效的手段。未来相信这些研究将对更高效、清洁的催化剂设计提供崭新的思路。 |
| 英文摘要: |
| It has been reported that precisely regulating the electronic structures of the active site is one of the most effective means to realize precise catalysis, which often includes lattice strain and charge transfer, etc. In doping systems, some new theories, such as the Atom-Realm (AR) effect, have been used to explain the changes in physical and chemical properties of the substrates caused by the geometry and electronic structures of the active heteroatom sites. Based on the low-entropy alloy and using the first-principles calculations, we report a new strategy for achieving precise catalysis through regulating the orbitals and spin of the active sites, i.e. doping Fe atoms in Pt to change its d-orbitals for the regulation of catalytic performance. We established both the models of pure Pt and Pt-Fe alloy and calculated the O2 adsorption energy on different active sites. We found that doping Fe atoms in pure Pt can weaken the binding of O2-Pt without affecting the O2 dissociation. Based on the projected density of states (PDOS) analysis, the hybridization of Fe-3d and Pt-5d states leads to the shift of atomic orbitals as well as the spin polarization of Pt metal. Therefore, part of the electronic states of Pt move above the Fermi level and overlap with O2-π*, making the hybridization of O2-π* and Pt-5d states in Pt-Fe alloy much stronger than that in pure Pt. The regulation of d-orbitals results in the improvement of the catalytic activity of O2 on the surface of Pt-Fe alloy. Our study predicts that the orbital catalysis and spin catalysis will provide an effective method for precise catalysis as well as high-efficient catalysts design. |
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