Tachikawa Hiroto
Division of Applied Chemistry, Graduate School of Engineering , Hokkaido University , Sapporo 060-8628 , Japan.
J Phys Chem A. 2019 Jun 6;123(22):4743-4749. doi: 10.1021/acs.jpca.9b03823. Epub 2019 May 23.
Carbon dioxide (CO) is one of the stable and inactive molecules that contribute to greenhouse gases. The development of new reactions of CO activation, chemical fixation, and conversion is a very important issue. In this report, the reactions of CO-HO binary clusters were investigated using a direct ab initio molecular dynamics (AIMD) method to find a new reaction of CO activation. Clusters composed of carbon dioxide and water molecules, CO(HO) ( n = 2-5), were utilized as a model of the binary cluster. The reaction dynamics of [CO(HO) ] following the ionization of parent neutral clusters were also investigated. Two electronic states of [CO(HO) ] were examined for direct AIMD surfaces: CO[(HO) ] (ground state) and (CO)(HO) (excited charge transfer (CT) state). After the ionization of the clusters, a proton-transfer (PT) reaction occurred within the (HO) moiety at the ground state, whereas the reactive HCO radical was formed at the CT state for OH addition to CO: CO(HO) → HCO + H(HO) . The mechanisms of the PT process and the HCO radical formation were discussed based on the theoretical results.
二氧化碳（CO₂）是导致温室气体的稳定且不活泼的分子之一。开发新的CO₂活化、化学固定及转化反应是一个非常重要的问题。在本报告中，使用直接从头算分子动力学（AIMD）方法研究了CO₂-H₂O二元团簇的反应，以寻找CO₂活化的新反应。由二氧化碳和水分子组成的团簇CO₂(H₂O)ₙ（n = 2 - 5）被用作二元团簇的模型。还研究了母体中性团簇电离后[CO₂(H₂O)ₙ]的反应动力学。针对直接AIMD表面研究了[CO₂(H₂O)ₙ]的两种电子态：CO₂[(H₂O)ₙ]（基态）和(CO₂)(H₂O)ₙ⁻（激发电荷转移（CT）态）。团簇电离后，基态时在(H₂O)ₙ部分内发生了质子转移（PT）反应，而在CT态下形成了反应性HCO自由基，用于OH加成到CO₂：CO₂(HO)₂ → HCO + H(HO)₂。基于理论结果讨论了PT过程和HCO自由基形成的机制。
