TY - JOUR
T1 - In situ Raman studies during sulfidation, and operando Raman-GC during ammoxidation reaction using nickel-containing catalysts
T2 - A valuable tool to identify the transformations of catalytic species
AU - Guerrero-Pérez, M. Olga
AU - Rojas, Elizabeth
AU - Gutiérrez-Alejandre, Aida
AU - Ramírez, Jorge
AU - Sánchez-Minero, Felipe
AU - Fernández-Vargas, César
AU - Bañares, Miguel A.
PY - 2011/5/28
Y1 - 2011/5/28
N2 - Ni-containing catalysts are investigated under reaction conditions for two different cases, during sulfidation, with Ni-Mo based catalysts, and during ammoxidation reaction, with the Ni-Nb catalysts. It is shown how Raman spectroscopy can follow some of the transformations of these catalysts upon different treatments. For the NiMo/Al2O3-SiO2 system it was possible to identify some of the sulfided Mo species formed during the sulfidation of the oxide precursors, while for the bulk Ni-Nb oxide catalysts the simultaneous reaction-Raman results strongly suggest that the incipient interaction between niobium and nickel oxides at low Nb/Ni atomic ratios is directly related to catalytic activity, and that a larger size well-defined NiNb2O6 mixed oxide phase is not active for this reaction. Moreover, the promotion by niobium doping appears to be limited to a moderate niobium loading. It was found that in situ and operando Raman are valuable techniques that allowed the identification of active Mo-S and Ni-Nb species under reaction conditions, and that are not stable under air atmospheres.
AB - Ni-containing catalysts are investigated under reaction conditions for two different cases, during sulfidation, with Ni-Mo based catalysts, and during ammoxidation reaction, with the Ni-Nb catalysts. It is shown how Raman spectroscopy can follow some of the transformations of these catalysts upon different treatments. For the NiMo/Al2O3-SiO2 system it was possible to identify some of the sulfided Mo species formed during the sulfidation of the oxide precursors, while for the bulk Ni-Nb oxide catalysts the simultaneous reaction-Raman results strongly suggest that the incipient interaction between niobium and nickel oxides at low Nb/Ni atomic ratios is directly related to catalytic activity, and that a larger size well-defined NiNb2O6 mixed oxide phase is not active for this reaction. Moreover, the promotion by niobium doping appears to be limited to a moderate niobium loading. It was found that in situ and operando Raman are valuable techniques that allowed the identification of active Mo-S and Ni-Nb species under reaction conditions, and that are not stable under air atmospheres.
UR - http://www.scopus.com/inward/record.url?scp=79955639133&partnerID=8YFLogxK
U2 - 10.1039/c0cp02242j
DO - 10.1039/c0cp02242j
M3 - Artículo
SN - 1463-9076
VL - 13
SP - 9260
EP - 9267
JO - Physical Chemistry Chemical Physics
JF - Physical Chemistry Chemical Physics
IS - 20
ER -