TY - JOUR
T1 - Heterometal incorporation in metal-exchanged zeolites enables low-temperature catalytic activity of NO x reduction
AU - Yang, Xiaofan
AU - Wu, Zili
AU - Moses-Debusk, Melanie
AU - Mullins, David R.
AU - Mahurin, Shannon M.
AU - Geiger, Robert A.
AU - Kidder, Michelle
AU - Narula, Chaitanya K.
PY - 2012/11/8
Y1 - 2012/11/8
N2 - A series of new heterobimetallic zeolites has been synthesized by incorporating a secondary metal cation M (Sc 3+, Fe 3+, In 3+, and La 3+) in Cu-exchanged ZSM-5, zeolite, and SSZ-13 zeolites under carefully controlled experimental conditions. Characterization by diffuse-reflectance ultraviolet-visible spectroscopy (UV-vis), X-ray powder diffraction (XRD), extended X-ray absorption fine structure spectroscopy (EXAFS), and electron paramagnetic resonance spectroscopy (EPR) does not permit conclusive structural determination but supports the proposal that M 3+ is hosted in zeolite structures in the vicinity of Cu(II), resulting in high NO x conversion activity at 150 °C. Among various zeolites reported here, CuFe-SSZ-13 offers the best NO x conversion activity in the 150-650 °C range and is hydrothermally stable when tested under accelerated aging conditions. Mechanistic studies employing stopped-flow diffuse reflectance FT-IR spectroscopy (DRIFTS) suggest that the high concentration of NO + generated by heterobimetallic zeolites is probably responsible for their superior low-temperature NO x activity.
AB - A series of new heterobimetallic zeolites has been synthesized by incorporating a secondary metal cation M (Sc 3+, Fe 3+, In 3+, and La 3+) in Cu-exchanged ZSM-5, zeolite, and SSZ-13 zeolites under carefully controlled experimental conditions. Characterization by diffuse-reflectance ultraviolet-visible spectroscopy (UV-vis), X-ray powder diffraction (XRD), extended X-ray absorption fine structure spectroscopy (EXAFS), and electron paramagnetic resonance spectroscopy (EPR) does not permit conclusive structural determination but supports the proposal that M 3+ is hosted in zeolite structures in the vicinity of Cu(II), resulting in high NO x conversion activity at 150 °C. Among various zeolites reported here, CuFe-SSZ-13 offers the best NO x conversion activity in the 150-650 °C range and is hydrothermally stable when tested under accelerated aging conditions. Mechanistic studies employing stopped-flow diffuse reflectance FT-IR spectroscopy (DRIFTS) suggest that the high concentration of NO + generated by heterobimetallic zeolites is probably responsible for their superior low-temperature NO x activity.
UR - http://www.scopus.com/inward/record.url?scp=84868674461&partnerID=8YFLogxK
U2 - 10.1021/jp3056043
DO - 10.1021/jp3056043
M3 - Article
AN - SCOPUS:84868674461
SN - 1932-7447
VL - 116
SP - 23322
EP - 23331
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 44
ER -