TY - JOUR
T1 - Enhanced catalytic performance of Ce-MCM-41-supported Rh for CO oxidation
AU - González Vargas, O. A.
AU - de Los Reyes Heredia, J. A.
AU - Suarez-Toriello, V. A.
AU - Anderson, Sean M.
AU - Chen, L. F.
AU - Wang, J. A.
N1 - Publisher Copyright:
© 2021, The Author(s), under exclusive licence to Springer Nature B.V.
PY - 2021/7
Y1 - 2021/7
N2 - 1wt%Rh/Ce-MCM-41 catalysts were prepared by the incipient wet impregnation method using mesoporous Ce-MCM-41 materials as supports where the Si/Ce molar ratios varied from 10 to 50. The structural properties and physicochemical features of the catalysts were characterized with a variety of techniques such as N2 physisorption, X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The CO adsorption–desorption behaviors on the catalysts were explored with in situ Fourier-transform infrared (FTIR) spectroscopic technique. The light-off curves of CO oxidation achieved on the Rh/Ce-MCM-41 catalysts significantly shifted toward lower temperature range compared to that achieved with the Rh/CeO2 and Rh/MCM-41 reference catalysts. The Rh/Ce-MCM-41 catalysts exhibited high activity with complete CO conversion at temperatures near 440 K. The in situ CO-FTIR spectra confirmed that several forms of Rh−O, Rh2−CO, Rh3−CO and Rh−(CO)2 carbonyl species with linear, bridged, hollow and gem-dicarbonyl bonds were formed. CO preferentially adsorbs on highly dispersed Rh clusters to form gem-dicarbonyl species. A reaction mechanism was proposed based primarily on the formation of intermediary species of CO adsorbed over Rh3+ clusters and the active O···OH oxygen species present on the surface in combination with the incorporation of Ce4+ ion into the framework of MCM-41 material. These findings suggest that the deposition of the Rh phase on the ceria-modified mesoporous supports could remarkably promote CO oxidation at low temperatures.
AB - 1wt%Rh/Ce-MCM-41 catalysts were prepared by the incipient wet impregnation method using mesoporous Ce-MCM-41 materials as supports where the Si/Ce molar ratios varied from 10 to 50. The structural properties and physicochemical features of the catalysts were characterized with a variety of techniques such as N2 physisorption, X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The CO adsorption–desorption behaviors on the catalysts were explored with in situ Fourier-transform infrared (FTIR) spectroscopic technique. The light-off curves of CO oxidation achieved on the Rh/Ce-MCM-41 catalysts significantly shifted toward lower temperature range compared to that achieved with the Rh/CeO2 and Rh/MCM-41 reference catalysts. The Rh/Ce-MCM-41 catalysts exhibited high activity with complete CO conversion at temperatures near 440 K. The in situ CO-FTIR spectra confirmed that several forms of Rh−O, Rh2−CO, Rh3−CO and Rh−(CO)2 carbonyl species with linear, bridged, hollow and gem-dicarbonyl bonds were formed. CO preferentially adsorbs on highly dispersed Rh clusters to form gem-dicarbonyl species. A reaction mechanism was proposed based primarily on the formation of intermediary species of CO adsorbed over Rh3+ clusters and the active O···OH oxygen species present on the surface in combination with the incorporation of Ce4+ ion into the framework of MCM-41 material. These findings suggest that the deposition of the Rh phase on the ceria-modified mesoporous supports could remarkably promote CO oxidation at low temperatures.
KW - CO oxidation
KW - Ce-MCM-41 materials
KW - Physicochemical characterization
KW - Supported Rh catalysts
UR - http://www.scopus.com/inward/record.url?scp=85103619407&partnerID=8YFLogxK
U2 - 10.1007/s11164-021-04436-4
DO - 10.1007/s11164-021-04436-4
M3 - Artículo
AN - SCOPUS:85103619407
SN - 0922-6168
VL - 47
SP - 2857
EP - 2880
JO - Research on Chemical Intermediates
JF - Research on Chemical Intermediates
IS - 7
ER -