Suppr超能文献

金掺杂二氧化铈还原表面上氧空位的修复

Healing of oxygen vacancies on reduced surfaces of gold-doped ceria.

作者信息

Nolan Michael

机构信息

Tyndall National Institute, Lee Maltings, Prospect Row, Cork, Ireland.

出版信息

J Chem Phys. 2009 Apr 14;130(14):144702. doi: 10.1063/1.3110702.

Abstract

As an oxidation-reduction catalyst, ceria can catalyze molecular oxidation and reduction. There has been a focus on understanding and enhancing the vacancy formation process to improve the oxidative power of ceria. However, it is important to also address healing of the surface vacancy. To investigate healing of oxygen vacancies in ceria, we study the interaction of atomic and molecular oxygen and NO(2) with oxygen vacancies on gold-doped (110) and (100) surfaces using density functional theory, corrected for on-site Coulomb interactions (DFT+U). For atomic and molecular oxygen, adsorption at the reduced surface is favorable and results in an oxygen atom sitting in an oxygen lattice site, healing the oxygen vacancy. On undoped surfaces, O(2) adsorbs as a peroxo (O(2)(2-)) species. However, on the doped (110) surface a superoxo (O(2)(-)) species is present. When NO(2) adsorbs (exothermically) at a divacancy surface, one oxygen of the molecule sits in the vacancy site and the N-O distances are elongated and an NO(2) anion forms, similar to the undoped surface. Vacancy healing of ceria surfaces is favorable, even if vacancy formation is enhanced, justifying the current focus on improving the oxidative power of ceria. We briefly examine a catalytic cycle: the reaction of CO with adsorbed O(2) on the undoped and doped surfaces, and find that the doped (110) surface facilitates CO oxidation.

摘要

作为一种氧化还原催化剂,二氧化铈能够催化分子的氧化和还原反应。人们一直致力于理解和强化空位形成过程,以提高二氧化铈的氧化能力。然而,表面空位的修复同样重要。为了研究二氧化铈中氧空位的修复情况,我们使用密度泛函理论(DFT+U,校正了在位库仑相互作用),研究了原子氧、分子氧和NO(2)与金掺杂的(110)和(100)表面上的氧空位之间的相互作用。对于原子氧和分子氧,在还原表面吸附是有利的,会导致一个氧原子占据氧晶格位置,从而修复氧空位。在未掺杂的表面上,O(2)以过氧根(O(2)(2-))物种的形式吸附。然而,在掺杂的(110)表面上存在超氧根(O(2)(-))物种。当NO(2)在双空位表面(放热地)吸附时,分子中的一个氧原子占据空位位置,N-O键距离拉长,形成NO(2)阴离子,这与未掺杂表面类似。二氧化铈表面的空位修复是有利的,即使空位形成有所增强,这也证明了当前对提高二氧化铈氧化能力的关注是合理的。我们简要研究了一个催化循环:CO与未掺杂和掺杂表面上吸附的O(2)的反应,发现掺杂的(110)表面促进了CO的氧化。

文献AI研究员

20分钟写一篇综述,助力文献阅读效率提升50倍。

立即体验

用中文搜PubMed

大模型驱动的PubMed中文搜索引擎

马上搜索

文档翻译

学术文献翻译模型,支持多种主流文档格式。

立即体验