Banerjee Arup, Ghanty Tapan K
Human Resources Development Section, Raja Ramanna Centre for Advanced Technology, Indore 452013, India and Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, India.
Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, India and Theoretical Chemistry Section, Chemistry Group, Bhabha Atomic Research Centre, Mumbai 400085, India and Bio-Science Group, Bhabha Atomic Research Centre, Mumbai 400085, India.
Phys Chem Chem Phys. 2021 Mar 11;23(9):5559-5570. doi: 10.1039/d0cp05756h.
Metallocarbohedrenes or metcars belong to one of the classes of stable nanoclusters having a specific stoichiometry. In spite of the available theoretical and experimental studies, the structure of pristine Ti8C12 metcar is still uncertain. We study the geometric structure of a titanium metcar, Ti8C12, together with its electronic properties and chemical activity towards adsorption and activation of CO2 molecule by means of density functional theory. Our results suggest that the CO2 molecule is strongly adsorbed and undergoes a significantly high degree of activation onto the Ti8C12 metcar. The migration of charge from titanium metcar to CO2 molecule attributes the high degree of activation of this molecule. In the infrared vibrational spectra for CO2 molecule adsorbed onto Ti8C12, we find a new signal which is absent in the corresponding spectra for gaseous CO2. In addition to adsorption energy, we also estimate the energy barrier for the dissociation of CO2 molecule to CO and O fragments on a Ti8C12 cluster. As a whole, this work reveals the ground state geometry of Ti8C12 metcar and highlights the role of this metcar in CO2 adsorption and activation, which are the key steps in designing potential catalysts for CO2 capture and its conversion to industrially valuable chemicals.
金属碳硼烷或金属碳簇属于具有特定化学计量比的稳定纳米团簇类别之一。尽管有可用的理论和实验研究，但原始的Ti8C12金属碳簇的结构仍然不确定。我们借助密度泛函理论研究了钛金属碳簇Ti8C12的几何结构及其电子性质以及对CO2分子吸附和活化的化学活性。我们的结果表明，CO2分子被强烈吸附并在Ti8C12金属碳簇上经历了显著程度的活化。电荷从钛金属碳簇向CO2分子的迁移归因于该分子的高度活化。在吸附于Ti8C12上的CO2分子的红外振动光谱中，我们发现了一个在气态CO2的相应光谱中不存在的新信号。除了吸附能，我们还估计了CO2分子在Ti8C12簇上分解为CO和O碎片的能垒。总体而言，这项工作揭示了Ti8C12金属碳簇的基态几何结构，并突出了该金属碳簇在CO2吸附和活化中的作用，而这是设计用于CO2捕获及其转化为工业上有价值化学品的潜在催化剂的关键步骤。
