Insights into adsorption performances and direct decomposition mechanisms of NO on [FeO]1+-ZSM-5: A density functional theory study
Insights into adsorption performances and direct decomposition mechanisms of NO on [FeO]1+-ZSM-5: A density functional theory study
复制标题
DOI：
10.1016/j.apsusc.2019.145212
复制
发表时间：
2020-04
影响因子：
6.7
通讯作者：
Sheng Shi;Miaoting Li;Chao Ge;Jianjun Lu;Pan Chen;P. Han;Zhifeng Yan
中科院分区：
文献类型：
--
作者：
Sheng Shi;Miaoting Li;Chao Ge;Jianjun Lu;Pan Chen;P. Han;Zhifeng Yan
本文采用密度泛函理论（DFT），利用簇模型系统研究了两种NO分子在[FeO]1+-ZSM-5表面的连续吸附性能及其直接分解机理。吸附结果表明，第一NO分子在[FeO]1+-ZSM-5上存在4种稳定的吸附构型，均为放热强化学吸附。从第一个NO分子在[FeO]1+-ZSM-5上的不同吸附构型开始，再到第二个NO分子在[FeO]1+-ZSM-5上的吸附构型，研究了N2O分子作为关键反应中间体，n2和o2作为目标产物的四种直接分解机理。基于热力学分析，提出了以第一个NO作为O-down吸附开始，遵循Eley-Rideal机制的η - 2-NO路径，其中ONNO和N2O是关键的催化中间体。全催化反应为放热反应，放出热量为43.76 kcal/mol。决定速率的步骤是N2（ads）的生成，即N2O（ads）→N2(ads) + O(ads)，其势垒能为39.09 kcal/mol。
The density functional theory (DFT) has been employed to systematically investigate the successive adsorption performances of two NO molecules onto [FeO]1+-ZSM-5 surface and subsequent direct decomposition mechanisms by using cluster model in this paper. The adsorption results indicate that there are four stable adsorption configurations of the first NO molecule on [FeO]1+-ZSM-5, all of which are exothermic and strong chemisorption. Beginning with different adsorption configurations of first NO molecule on [FeO]1+-ZSM-5 followed by the adsorption of the second NO molecule, all four direct decomposition mechanisms are studied in which N2O molecule acts as the key reaction intermediate, N2and O2act as the target products. Based on thermodynamic analysis, η2-NO path that starts with adsorption of the first NO as O-down and follows the Eley-Rideal mechanism is proposed, in which ONNO species and N2O are the key catalytic intermediates. The full catalytic reaction is exothermic by 43.76 kcal/mol. The rate-determining step is the formation of N2(ads), i.e. N2O(ads) → N2(ads) + O(ads) and its barrier energy is 39.09 kcal/mol.