Rybakov A A, Larin A V, Vercauteren D P
Chemistry Department, Moscow State University, Leninskie Gory, Moscow, GSP-2 119991, Russia.
University of Namur, Rue de Bruxelles 61, Namur, B-5000, Belgium.
Phys Chem Chem Phys. 2017 Aug 9;19(31):20930-20940. doi: 10.1039/c7cp03043f.
Our work is devoted to DFT calculations of the relative rotational and diffusional barriers for CO motions in zeolite NaY. The diffusion jump of CO adsorbed in NaY from NaII to Na'II has been confirmed as the favored way for CO re-coordination via either the C or the O atom to the Na cations instead of the CO rotation, hence explaining the mechanism which is responsible for the CO exchange between different positions and the changes in the intensities of the vibrational IR spectra. The fine structure of the vibrational C-O bands is explained by the different CO locations of adsorbed mono- and dicarbonyl species. The calculated activation energy of intra-cage CO diffusion from NaII-CO to Na'II-OC matches the respective experimental barrier observed in the NaX zeolite.
我们的工作致力于对沸石NaY中CO运动的相对旋转和扩散势垒进行密度泛函理论（DFT）计算。已证实吸附在NaY中的CO从NaII位扩散跃迁到Na'II位是CO通过C或O原子与Na阳离子重新配位的有利方式，而非CO旋转，从而解释了不同位置间CO交换以及红外振动光谱强度变化的机制。吸附的单羰基和二羰基物种的不同CO位置解释了振动C - O带的精细结构。计算得到的笼内CO从NaII - CO扩散到Na'II - OC的活化能与在NaX沸石中观察到的相应实验势垒相匹配。
