Indoor formaldehyde (HCHO) pollution poses a major risk to human health. Low-temperature catalytic oxidation is an effective method for HCHO removal. The high activity and selectivity of single atomic catalysts provide a possibility for the development of efficient non-precious metal catalysts. In this study, the most stable single-atom catalyst Ti–TiCO was screened by density functional theory among many single atomic catalysts with two-dimensional (2D) monolayer TiCO as the support. The computational results show that Ti–TiCO is highly selective to HCHO and O in complex environments. The HCHO oxidation reaction pathways are proposed based on the Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) mechanisms. According to the reaction energy and energy span models, the E-R mechanism has a lower maximum energy barrier and higher catalytic efficiency than the L-H mechanism. In addition, the stability of the Ti–TiCO structure and active center was verified by diffusion energy barrier and ab initio molecular dynamics simulations. The above results indicate that Ti–TiCO is a promising non-precious metal catalyst. The present study provides detailed theoretical insights into the catalytic oxidation of HCHO by Ti–TiCO, as well as an idea for the development of efficient non-precious metal catalysts based on 2D materials.

中文翻译：

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基于密度泛函理论筛选 Ti4C3O2 负载单原子用于高效选择性催化氧化甲醛

室内甲醛（HCHO）污染对人类健康构成重大风险。低温催化氧化是去除HCHO的有效方法。单原子催化剂的高活性和选择性为开发高效非贵金属催化剂提供了可能。本研究通过密度泛函理论在众多以二维（2D）单层TiCO为载体的单原子催化剂中筛选出最稳定的单原子催化剂Ti-TiCO。计算结果表明，Ti-TiCO在复杂环境中对HCHO和O具有高度选择性。 HCHO 氧化反应途径是基于 Eley-Rideal (ER) 和 Langmuir-Hinshelwood (LH) 机制提出的。根据反应能和能跨模型，ER机制比LH机制具有更低的最大能垒和更高的催化效率。此外，通过扩散能垒和从头算分子动力学模拟验证了Ti-TiCO结构和活性中心的稳定性。上述结果表明Ti-TiCO是一种很有前景的非贵金属催化剂。本研究为Ti-TiCO催化氧化HCHO提供了详细的理论见解，并为开发基于二维材料的高效非贵金属催化剂提供了思路。