[Model catalyst studies of active sites and meta L support interactions on vanadia and vanadia-supported catalysts]

Abstract The influence of Al2O3–ZrO2 and TiO2–ZrO2 supports on NiMo-supported catalysts at a different sulfur concentration in a model hydrodeoxygenation (HDO)-hydrodesulfurization (HDS) co-processing reaction has been studied in this work. A competition effect between phenol and dibenzothiophene (DBT) for active sites was evidenced. The competence for the active sites between phenol and DBT was measured by comparison of the initial reaction rate and selectivity at two sulfur concentrations (200 and 500 ppm S). NiMo/TiO2–ZrO2 was almost four-fold more active in phenol HDO co-processed with DBT than NiMo/Al2O3–ZrO2 catalyst. Consequently, more labile active sites are present on NiMo/TiO2–ZrO2 than in NiMo/Al2O3–ZrO2 confirmed by the decrease in co-processing competition for the active sites between phenol and DBT. DBT molecules react at hydrogenolysis sites (edge and rim) preferentially so that phenol reacts at hydrogenation sites (edge and edge). However, the hydrogenated capacity would be lost when the sulfur content was increased. In general, both catalysts showed similar functionalities but different degrees of competition according to the highly active NiMoS phase availability. TiO2–ZrO2 as the support provided weaker metal-support interaction than Al2O3–ZrO2, generating a larger fraction of easily reducible octahedrally coordinated Mo- and Ni-oxide species, causing that NiMo/TiO2–ZrO2 generated precursors of MoS2 crystallites with a longer length and stacking but with a higher degree of Ni-promotion than NiMo/Al2O3–ZrO2 catalyst.

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Effect of the oxygen coordination environment of Ca–Mn oxides on the catalytic performance of Pd supported catalysts for aerobic oxidation of 5-hydroxymethyl-2-furfural

Catalysis Science & Technology ◽

10.1039/c9cy01298b ◽

2019 ◽

Vol 9 (23) ◽

pp. 6659-6668 ◽

Cited By ~ 5

Author(s):

Jie Yang ◽

Haochen Yu ◽

Yanbing Wang ◽

Fuyuan Qi ◽

Haodong Liu ◽

...

Keyword(s):

Catalytic Activity ◽

Charge Transfer ◽

Active Sites ◽

Supported Catalysts ◽

Aerobic Oxidation ◽

Oxygen Adsorption ◽

Catalytic Performance ◽

Coordination Environment ◽

Oxygen Coordination ◽

Mn Oxides

Pd/CaMn2O4 provides ideal active sites for oxygen adsorption and desorption, resulting in the promoted charge transfer ability and catalytic activity.

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Engineering active sites on reduced graphene oxide by hydrogen plasma irradiation: mimicking bifunctional metal/supported catalysts in hydrogenation reactions

Green Chemistry ◽

10.1039/c7gc03397d ◽

2018 ◽

Vol 20 (11) ◽

pp. 2611-2623 ◽

Cited By ~ 8

Author(s):

Ana Primo ◽

Antonio Franconetti ◽

Monica Magureanu ◽

Nicolae Bogdan Mandache ◽

Cristina Bucur ◽

...

Keyword(s):

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Active Sites ◽

Supported Catalysts ◽

Hydrogen Plasma ◽

Hydrogenation Catalyst ◽

Plasma Irradiation ◽

Reduced Graphene ◽

Hydrogenation Reactions

H2 plasma generates carbon vacancies on reduced graphene oxide increasing its activity as a hydrogenation catalyst.

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Role of the Exposed Pt Active Sites and BaO2 Formation in NOx Storage Reduction Systems: A Model Catalyst Study on BaOx/Pt(111)

The Journal of Physical Chemistry C ◽

10.1021/jp208269x ◽

2011 ◽

Vol 115 (49) ◽

pp. 24256-24266 ◽

Cited By ~ 8

Author(s):

Evgeny I. Vovk ◽

Emre Emmez ◽

Mehmet Erbudak ◽

Valerii I. Bukhtiyarov ◽

Emrah Ozensoy

Keyword(s):

Active Sites ◽

Model Catalyst ◽

Nox Storage ◽

Nox Storage Reduction

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Metallic Pt as active sites for the water–gas shift reaction on alkali-promoted supported catalysts

Journal of Catalysis ◽

10.1016/j.jcat.2011.11.017 ◽

2012 ◽

Vol 286 ◽

pp. 279-286 ◽

Cited By ~ 79

Author(s):

Jorge H. Pazmiño ◽

Mayank Shekhar ◽

W. Damion Williams ◽

M. Cem Akatay ◽

Jeffrey T. Miller ◽

...

Keyword(s):

Active Sites ◽

Supported Catalysts ◽

Water Gas Shift ◽

Water Gas Shift Reaction ◽

Shift Reaction ◽

Water Gas

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CO2 reforming of methane over Ni-Ru supported catalysts: On the nature of active sites by operando DRIFTS study

Journal of CO2 Utilization ◽

10.1016/j.jcou.2018.01.027 ◽

2018 ◽

Vol 24 ◽

pp. 509-515 ◽

Cited By ~ 20

Author(s):

A. Álvarez M. ◽

L.F. Bobadilla ◽

V. Garcilaso ◽

M.A. Centeno ◽

J.A. Odriozola

Keyword(s):

Active Sites ◽

Supported Catalysts ◽

Co2 Reforming ◽

Co2 Reforming Of Methane

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Infrared Spectroscopic Characterization of Sulfide Cluster-Derived Ensembles

MRS Proceedings ◽

10.1557/proc-368-203 ◽

1994 ◽

Vol 368 ◽

Cited By ~ 1

Author(s):

James R. Brenner ◽

Levi T. Thompson

Keyword(s):

Transition Metal ◽

Active Sites ◽

Supported Catalysts ◽

Bond Cleavage ◽

Metal Sulfide ◽

Spectroscopic Characterization ◽

Incipient Wetness Impregnation ◽

Late Transition Metals ◽

Late Transition ◽

Thiophene Hds

ABSTRACTThe transition metal sulfide clusters (MeCp)2Mo2(μ-SH)2(μ-S)2, (MeCp)2Mo2Co2(μ3-S)2(μ4-S)(CO)4 [MoCoS], and (MeCp)2Mo2 Fe2 (μ3-S)2(CO)8, (MeCp = methylcyclopentadienyl) were used to prepare γ-Al2O3-supported catalysts. For comparison, a series of supported materials was also prepared using conventional incipient wetness impregnation. Infrared spectroscopy of adsorbed species was used to characterize the sites in the clusterderived and conventionally prepared catalysts. Nitric oxide chemisorbed onto the MoCoS/A catalyst was associated initially only with Co sites and then upon gentle heating shifted to the Mo sites, indicating that Co and Mo were in close proximity. In contrast, NO adsorbed onto both Co and Mo sites in the conventionally prepared materials and desorbed independently from these two types of sites. Infrared spectra of adsorbed thiophene and pyridine were similar for the clusterderived and conventionally prepared catalysts. Thiophene reacted at 100 °C to produce both olefinic species. The most abundant products from thiophene HDS were 1-butene, cis-2-butene, and trans-2-butene. Displacement studies showed that thiophene, pyridine, and NO adsorbed to the same site. The most active sites for HDS and HDN contained both Mo and a late transition metal. The HDN product distributions suggested that Mo was selective for C=N bond cleavage while the late transition metals were more active for C=C hydrogenolysis.

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