催化作用
掺杂剂
离解(化学)
选择性催化还原
吸附
化学
路易斯酸
密度泛函理论
解吸
兴奋剂
材料科学
氨
无机化学
光化学
物理化学
计算化学
有机化学
光电子学
作者
Chirawat Chitpakdee,Anchalee Junkaew,Phornphimon Maitarad,Liyi Shi,Vinich Promarak,Nawee Kungwan,Supawadee Namuangruk
标识
DOI:10.1016/j.cej.2019.03.053
摘要
Reaction mechanism of the selective catalytic reduction of nitric oxide (NO) by ammonia (NH3-SCR of NO) on the Ru-doped CeO2(111) surface was investigated using density functional theory calculation corrected by on-site Coulomb interactions (DFT + U) to understand the role of Ru dopant toward the catalytic performance of CeO2 based catalysts. The NH3-SCR of NO mechanisms on Ru-CeO2, which consisted of two consecutive NO reduction pathways, were systematically examined. Each NO reduction consists of important elementary steps such as NH3 adsorption/dissociation and water formation/desorption. The calculated results reveal that the Ru dopant substantially affects on the electronic charge property and enhances the Lewis acidity of the CeO2 surface. The NH3 adsorption and dissociation take place at the Lewis acid site of the catalyst. The first NO reduction via the NHNO intermediate is facile when the Ru dopant presents on the catalyst surface. The presence of Brønsted acid on surface catalyst suppresses the NH3 adsorption and dissociation but helps in promoting the water formation, which is the rate-determining step of overall reaction. Thus, the performance of this catalyst can be further enhanced by improving the water formation aspect. The obtained results deepen the fundamental understanding of the role of the different active sites on the crucial steps during the reaction and are useful for guiding the way to develop catalysts used in this application.
科研通智能强力驱动
Strongly Powered by AbleSci AI