Theoretical Investigation of the Interaction between Carbon Monoxide and Carbon Nanotubes with Single‐Vacancy Defects |
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| Authors: | Dr Bo Xiao Dr Jing‐xiang Zhao Prof Yi‐hong Ding Prof Chia‐chung Sun |
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| Institution: | 1. State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023 (China), Fax: (+86)?431‐88498026;2. College of Chemistry and Chemical Engineering, Harbin Normal University, Harbin 150025 (China) |
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| Abstract: | Density functional theory calculations are used to study the healing process of a defective CNT (i.e. (8,0) CNT) by CO molecules. The healing undergoes three evolutionary steps: 1) the chemisorption of the first CO molecule, 2) the incorporation of the C atom of CO into the CNT, accompanied by the adsorption of the leaving O atom on the CNT surface, 3) the removal of the adsorbed O atom from the CNT surface by a second CO molecule to form CO2 and the perfect CNT. Overall, adsorption of the first CO reveals a barrier of 2.99 kcal mol?1 and is strongly exothermal by 109.11 kcal mol?1, while adsorption of a second CO has an intrinsic barrier of 32.37 kcal mol?1and is exothermal by 62.34 kcal mol?1. In light of the unique conditions of CNT synthesis, that is, high temperatures in a closed container, the healing of the defective CNT could be effective in the presence of CO molecules. Therefore, we propose that among the available CNT synthesis procedures, the good performance of chemical vapor decomposition of CO on metal nanoparticles might be ascribed to the dual role of CO, that is, CO acts both as a carbon source and a defect healer. The present results are expected to help a deeper understanding of CNT growth. |
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| Keywords: | carbon monoxide computational chemistry nanotubes reaction mechanisms transition states |
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