Omidvar Akbar
Young Researchers and Elite Club, Lahijan Branch, Islamic Azad University, Lahijan, Iran.
J Mol Graph Model. 2017 Oct;77:218-224. doi: 10.1016/j.jmgm.2017.09.001. Epub 2017 Sep 4.
The activation of the O molecule and yielding two separated O atoms is an essential step for the oxygen reduction reaction processes. Dissociation of the strong bond in the O often involves large activation barriers on metal particles used as catalysts. Here, the catalytic activity for the O dissociation of the transition metals (Fe, Co, Ni, Cu, Rh, Pd, Ag, Ir, Pt, and Au) deposited on the BN nanocluster have been studied theoretically using density functional theory. The following outcomes can be derived from our calculations: (1) The strong interaction between the Fe and Ni metal atoms and boron atom in BN nanocluster suggests that these transition metals deposited on BN nanocluster should be stable under high temperatures. (2) Transition metal deposition enhances the reactivity of BN nanocluster, however, it is more effective in the case of Fe-deposited on BN nanocluster. (3) Consistent with the prediction of reactivity descriptors, the maximum catalytic activity toward O dissociation is related to the Fe-deposited on BN nanoclusters. (4) The adsorption energies of the O adsorbed on the metal-deposited BN nanoclusters increase with the increase transition metals positive charges. (5) The energy barrier of the O dissociation is significantly decreased by introducing extra positive charges into the metal deposited on the BN nanocluster. Our study demonstrates that the transition metals-deposited on the BN nanoclusters can act as driving force for O dissociation. These predictions open the route for the experimental studies of catalysts that offer high activity for oxygen reduction reaction processes.
氧分子的活化并生成两个分离的氧原子是氧还原反应过程的关键步骤。氧分子中强化学键的解离在用作催化剂的金属颗粒上通常涉及较大的活化能垒。在此,我们使用密度泛函理论从理论上研究了沉积在BN纳米团簇上的过渡金属(Fe、Co、Ni、Cu、Rh、Pd、Ag、Ir、Pt和Au)对氧解离的催化活性。从我们的计算中可以得出以下结果:(1)BN纳米团簇中Fe和Ni金属原子与硼原子之间的强相互作用表明,沉积在BN纳米团簇上的这些过渡金属在高温下应该是稳定的。(2)过渡金属沉积增强了BN纳米团簇的反应活性,然而,在Fe沉积在BN纳米团簇的情况下更有效。(3)与反应活性描述符的预测一致,对氧解离的最大催化活性与沉积在BN纳米团簇上的Fe有关。(4)吸附在金属沉积的BN纳米团簇上的氧的吸附能随着过渡金属正电荷的增加而增加。(5)通过向沉积在BN纳米团簇上的金属引入额外的正电荷,氧解离的能垒显著降低。我们的研究表明,沉积在BN纳米团簇上的过渡金属可以作为氧解离的驱动力。这些预测为氧还原反应过程中具有高活性的催化剂的实验研究开辟了道路。