Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea.
J Am Chem Soc. 2011 Feb 23;133(7):2084-7. doi: 10.1021/ja1101807. Epub 2011 Feb 2.
Carbon dioxides (CO(2)) emitted from large-scale coal-fired power stations or industrial manufacturing plants have to be properly captured to minimize environmental side effects. From results of ab initio calculations using plane waves [PAW-PBE] and localized atomic orbitals [ONIOM(wB97X-D/6-31G*:AM1)], we report strong CO(2) adsorption on boron antisite (B(N)) in boron-rich boron nitride nanotube (BNNT). We have identified two adsorption states: (1) A linear CO(2) molecule is physically adsorbed on the B(N), showing electron donation from the CO(2) lone-pair states to the B(N) double-acceptor state, and (2) the physisorbed CO(2) undergoes a carboxylate-like structural distortion and C═O π-bond breaking due to electron back-donation from B(N) to CO(2). The CO(2) chemisorption energy on B(N) is almost independent of tube diameter and, more importantly, higher than the standard free energy of gaseous CO(2) at room temperature. This implies that boron-rich BNNT could capture CO(2) effectively at ambient conditions.
从大型火力发电站或工业制造厂排放的二氧化碳（CO2）必须经过适当的捕获，以将其对环境的副作用降到最低。通过使用平面波[PAW-PBE]和局域原子轨道[ONIOM（wB97X-D/6-31G*：AM1）]的从头算计算结果，我们报告了富硼氮化硼纳米管（BNNT）中硼反位（B（N））上 CO2 的强吸附作用。我们已经确定了两种吸附状态：（1）线性 CO2 分子物理吸附在 B（N）上，表现出 CO2 孤对态向 B（N）双受体态的电子供体，以及（2）物理吸附的 CO2 经历类似羧酸盐的结构扭曲和 C=O π键断裂，因为电子从 B（N）向后供体到 CO2。B（N）上 CO2 的化学吸附能几乎与管直径无关，更重要的是，高于室温下气态 CO2 的标准自由能。这意味着富硼 BNNT 可以在环境条件下有效捕获 CO2。
