TY - JOUR
T1 - In situ characterization of highly dispersed, ceria-supported fe sites for no reduction by CO
AU - Roberts, Charles A.
AU - Prieto-Centurion, Dario
AU - Nagai, Yasutaka
AU - Nishimura, Yusaku F.
AU - Desautels, Ryan D.
AU - Van Lierop, Johan
AU - Fanson, Paul T.
AU - Notestein, Justin M.
PY - 2015/2/26
Y1 - 2015/2/26
N2 - Highly dispersed FeOx was impregnated onto CeO2 using the unique precursor Na/Fe-ethylenediaminetetraacetate (NaFeEDTA) at varying Fe surface density (0-1.5 Fe/nm2). These catalysts were used for NO reduction by CO and were compared to a more traditional Fe(NO3)3 precursor impregnated on Na-promoted CeO2. Extensive characterization and spectroscopic measurements showed that NaFeEDTA produced a narrower distribution of smaller, noncrystalline, surface FeOx species with excellent redox cyclability (Fe3+ → Fe2+). The NaFeEDTA catalysts exhibited corresponding higher steady-state activity for NO reduction by CO. In situ X-ray absorption spectroscopy with simultaneous gas-phase monitoring indicated that NO conversion began concurrent with reduction of Fe and Ce, suggesting that NO reduction occurred at a reduced Fe-O-Ce interface site. These results illustrate a new synthesis-structure-activity relationship for NO reduction by CO over redox-cycling FeOx sites that may support future rational design of emission control catalysts without Pt-group metals or zeolites.
AB - Highly dispersed FeOx was impregnated onto CeO2 using the unique precursor Na/Fe-ethylenediaminetetraacetate (NaFeEDTA) at varying Fe surface density (0-1.5 Fe/nm2). These catalysts were used for NO reduction by CO and were compared to a more traditional Fe(NO3)3 precursor impregnated on Na-promoted CeO2. Extensive characterization and spectroscopic measurements showed that NaFeEDTA produced a narrower distribution of smaller, noncrystalline, surface FeOx species with excellent redox cyclability (Fe3+ → Fe2+). The NaFeEDTA catalysts exhibited corresponding higher steady-state activity for NO reduction by CO. In situ X-ray absorption spectroscopy with simultaneous gas-phase monitoring indicated that NO conversion began concurrent with reduction of Fe and Ce, suggesting that NO reduction occurred at a reduced Fe-O-Ce interface site. These results illustrate a new synthesis-structure-activity relationship for NO reduction by CO over redox-cycling FeOx sites that may support future rational design of emission control catalysts without Pt-group metals or zeolites.
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U2 - 10.1021/jp5126975
DO - 10.1021/jp5126975
M3 - Article
AN - SCOPUS:84923975152
VL - 119
SP - 4224
EP - 4234
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 8
ER -