电子顺磁共振
铜
傅里叶变换红外光谱
化学
离子
分析化学(期刊)
光谱学
红外光谱学
ZSM-5型
分子
核化学
结晶学
催化作用
沸石
核磁共振
有机化学
物理
量子力学
作者
Filippo Giordanino,Peter N. R. Vennestrøm,L. F. Lundegaard,Frederick N. Stappen,Susanne Mossin,Pablo Beato,Silvia Bordiga,Carlo Lamberti
出处
期刊:Dalton Transactions
[Royal Society of Chemistry]
日期:2013-01-01
卷期号:42 (35): 12741-12741
被引量:350
摘要
Cu-SSZ-13 has been characterized by different spectroscopic techniques and compared with Cu-ZSM-5 and Cu-β with similar Si/Al and Cu/Al ratios and prepared by the same ion exchange procedure. On vacuum activated samples, low temperature FTIR spectroscopy allowed us to appreciate a high concentration of reduced copper centres, i.e. isolated Cu(+) ions located in different environments, able to form Cu(+)(N2), Cu(+)(CO)n (n = 1, 2, 3), and Cu(+)(NO)n (n = 1, 2) upon interaction with N2, CO and NO probe molecules, respectively. Low temperature FTIR, DRUV-Vis and EPR analysis on O2 activated samples revealed the presence of different Cu(2+) species. New data and discussion are devoted to (i) [Cu-OH](+) species likely balanced by one framework Al atom; (ii) mono(μ-oxo)dicopper [Cu2(μ-O)](2+) dimers observed in Cu-ZSM-5 and Cu-β, but not in Cu-SSZ-13. UV-Vis-NIR spectra of O2 activated samples reveal an intense and finely structured d-d quadruplet, unique to Cu-SSZ-13, which is persistent under SCR conditions. This differs from the 22,700 cm(-1) band of the mono(μ-oxo)dicopper species of the O2 activated Cu-ZSM-5, which disappears under SCR conditions. The EPR signal intensity sets Cu-β apart from the others.
科研通智能强力驱动
Strongly Powered by AbleSci AI