Theoretical and Computational Chemistry Group, Department of Chemistry, Centre of Advanced Studies in Chemistry, Panjab University, Chandigarh 160014, India.
Guru Gobind Singh College For Women, Sector-26, Chandigarh 160014, India.
Molecules. 2021 Oct 24;26(21):6415. doi: 10.3390/molecules26216415.
Molecular level insights into the mechanism and thermodynamics of CO oxidation by a (TiO2)6 cluster have been obtained through density functional calculations. Thereby, in this study, as an example, two different structural isomers of (TiO2)6 are considered with the purpose of understanding the interplay between local structure and activity for the CO oxidation reaction. Active sites in the two isomeric forms were identified on the basis of global and local reactivity descriptors. For the oxidation of CO to CO2, the study considered both sequential and simultaneous adsorption of CO and O2 on (TiO2)6 cluster through the ER and LH mechanisms, respectively. Three different pathways were obtained for CO oxidation by (TiO2)6 cluster, and the mechanistic route of each pathway were identified by locating the transition-state and intermediate structures. The effect of temperature on the rate of the reaction was investigated within the harmonic approximation. The structure-dependent activity of the cluster was rationalized through reactivity descriptors and analysis of the frontier orbitals.
通过密度泛函计算，深入了解了(TiO2)6 簇催化 CO 氧化的反应机制和热力学。在这项研究中，作为一个例子，考虑了(TiO2)6 的两种不同结构异构体，目的是理解局部结构与 CO 氧化反应活性之间的相互作用。基于全局和局部反应性描述符，确定了两种异构形式中的活性位。对于 CO 到 CO2 的氧化，通过 ER 和 LH 机制，分别考虑了 CO 和 O2 在(TiO2)6 簇上的顺序和同时吸附。通过(TiO2)6 簇氧化 CO 得到了三种不同的途径，并通过定位过渡态和中间体结构确定了每条途径的反应机理。在谐波近似下，研究了温度对反应速率的影响。通过反应性描述符和前线轨道分析，对团簇的结构依赖性活性进行了合理化。
