Title: | Mechanistic insight into selective catalytic combustion of HCN over Cu-BEA: influence of different active center structures |
Author(s): | Liu N; Yuan X; Zhang R; Li Y; Chen B; |
Address: | "State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China. zhangrd@mail.buct.edu.cn" |
ISSN/ISBN: | 1463-9084 (Electronic) 1463-9076 (Linking) |
Abstract: | "HCN being a highly toxic N-containing volatile organic compound (VOCs) poses great threat to human living environment. Selective catalytic combustion of HCN (HCN-SCC) over metal modified zeolite catalysts has attracted great attention due to related high efficiency and excellent N(2) selectivity. In the present work, three types of 24T-Cu-BEA models with different active centers of single [Cu](+), double [Cu](+), and [Cu-O-Cu](2+) were constructed for HCN-SCC mechanism simulations based on density functional theory (DFT). DFT simulation results revealed that HCN-SCC followed an oxidation mechanism over double [Cu](+) through an intermediate of NCO, wherein the synergistic effects of double [Cu](+) active centers were clearly observed, resulting in a significantly lowered energy barrier (1.6 kcal mol(-1)) during HCN oxidation into NCO. However, an oxidation mechanism (HCN oxidized into NH radical and CO(2) through intermediate of HNCO) combining with a hydrolysis mechanism (NH radical hydrolyses into NH(3)) occurred over single [Cu](+) and [Cu-O-Cu](2+), wherein the NH(2) hydrolysis to NH(3) step was regarded as the rate determining step with an energy barrier of 72.3 and 74.3 kcal mol(-1), respectively. Finally, Mulliken charge transfer (CT) analysis was conducted, based on which the electric properties of different active centers were well illustrated" |
Notes: | "PubMed-not-MEDLINELiu, Ning Yuan, Xiaoning Zhang, Runduo Li, Yingxia Chen, Biaohua eng England 2017/08/24 Phys Chem Chem Phys. 2017 Sep 13; 19(35):23960-23970. doi: 10.1039/c7cp04604a" |