Synthesis, Structure, and Catalytic Performance in Cyclooctene Epoxidation of a Molybdenum Oxide/Bipyridine Hybrid Material: {[MoO3(bipy)][MoO3(H2O)]}n

2010 ◽  
Vol 49 (15) ◽  
pp. 6865-6873 ◽  
Author(s):  
Marta Abrantes ◽  
Tatiana R. Amarante ◽  
Margarida M. Antunes ◽  
Sandra Gago ◽  
Filipe A. Almeida Paz ◽  
...  
Keyword(s):  
Molybdenum Oxide ◽  
Hybrid Material ◽  
Catalytic Performance ◽  
Cyclooctene Epoxidation

Active and stable ceria-zirconia supported molybdenum oxide catalysts for cyclooctene epoxidation: Effect of the preparation procedure

2020 ◽  
Vol 345 ◽  
pp. 201-212 ◽  
Author(s):  
R. Turco ◽  
B. Bonelli ◽  
M. Armandi ◽  
L. Spiridigliozzi ◽  
G. Dell’Agli ◽  
...  
Keyword(s):  
Molybdenum Oxide ◽  
Oxide Catalysts ◽  
Preparation Procedure ◽  
Cyclooctene Epoxidation

scholarly journals Enhanced Photocatalytic Activity and Stability in Hydrogen Evolution of Mo6 Iodide Clusters Supported on Graphene Oxide

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1259
Author(s):  
Marta Puche ◽  
Rocío García-Aboal ◽  
Maxim A. Mikhaylov ◽  
Maxim N. Sokolov ◽  
Pedro Atienzar ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Gas Phase ◽  
Hybrid Material ◽  
Liquid Water ◽  
Catalytic Performance ◽  
H2 Production ◽  
Cluster Compound ◽  
Catalytic Systems ◽  
Active Cluster ◽  
First Time

Catalytic properties of the cluster compound (TBA)2[Mo6Ii8(O2CCH3)a6] (TBA = tetrabutylammonium) and a new hybrid material (TBA)2Mo6Ii8@GO (GO = graphene oxide) in water photoreduction into molecular hydrogen were investigated. New hybrid material (TBA)2Mo6Ii8@GO was prepared by coordinative immobilization of the (TBA)2[Mo6Ii8(O2CCH3)a6] onto GO sheets and characterized by spectroscopic, analytical, and morphological techniques. Liquid and, for the first time, gas phase conditions were chosen for catalytic experiments under UV–Vis irradiation. In liquid water, optimal H2 production yields were obtained after using (TBA)2[Mo6Ii8(O2CCH3)a6] and (TBA)2Mo6Ii8@GO) catalysts after 5 h of irradiation of liquid water. Despite these remarkable catalytic performances, “liquid-phase” catalytic systems have serious drawbacks: the cluster anion evolves to less active cluster species with partial hydrolytic decomposition, and the nanocomposite completely decays in the process. Vapor water photoreduction showed lower catalytic performance but offers more advantages in terms of cluster stability, even after longer radiation exposure times and recyclability of both catalysts. The turnover frequency (TOF) of (TBA)2Mo6Ii8@GO is three times higher than that of the microcrystalline (TBA)2[Mo6Ii8(O2CCH3)a6], in agreement with the better accessibility of catalytic cluster sites for water molecules in the gas phase. This bodes well for the possibility of creating {Mo6I8}4+-based materials as catalysts in hydrogen production technology from water vapor.

Molybdenum oxide modified HZSM-5 catalyst: Surface acidity and catalytic performance for the dehydration of aqueous ethanol

2011 ◽  
Vol 396 (1-2) ◽  
pp. 8-13 ◽  
Author(s):  
Yuwang Han ◽  
Cuiyun Lu ◽  
Dongsheng Xu ◽  
Yelong Zhang ◽  
Yi Hu ◽  
...  
Keyword(s):  
Molybdenum Oxide ◽  
Aqueous Ethanol ◽  
Catalyst Surface ◽  
Surface Acidity ◽  
Catalytic Performance

scholarly journals Catalytic Performance of Bulk and Al2O3-Supported Molybdenum Oxide for the Production of Biodiesel from Oil with High Free Fatty Acids Content

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 158 ◽  
Author(s):  
Alberto Navajas ◽  
Inés Reyero ◽  
Elena Jiménez-Barrera ◽  
Francisca Romero-Sarria ◽  
Jordi Llorca ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Molybdenum Oxide ◽  
Solid Acid ◽  
Reaction Medium ◽  
Active Phase ◽  
Catalytic Performance ◽  
Acid Catalysts ◽  
Basic Catalysts ◽  
Esterification Reactions

Non-edible vegetable oils are characterized by high contents of free fatty acids (FFAs) that prevent from using the conventional basic catalysts for the production of biodiesel. In this work, solid acid catalysts are used for the simultaneous esterification and transesterification with methanol of the FFAs and triglycerides contained in sunflower oil acidified with oleic acid. Molybdenum oxide (MoO3), which has been seldom considered as a catalyst for the production of biodiesel, was used in bulk and alumina-supported forms. Results showed that bulk MoO3 is very active for both transesterification and esterification reactions, but it suffered from severe molybdenum leaching in the reaction medium. When supported on Al2O3, the MoO3 performance improved in terms of active phase utilization and stability though molybdenum leaching remained significant. The improvement of catalytic performance was ascribed to the establishment of MoO3-Al2O3 interactions that favored the anchorage of molybdenum to the support and the formation of new strong acidic centers, although this effect was offset by a decrease of specific surface area. It is concluded that the development of stable catalysts based on MoO3 offers an attractive route for the valorization of oils with high FFAs content.

A novel organic–inorganic hybrid material: production, characterization and catalytic performance for the reaction of arylaldehydes, dimedone and 6-amino-1,3-dimethyluracil

2020 ◽  
Vol 44 (12) ◽  
pp. 4736-4743 ◽  
Author(s):  
Abdolkarim Zare ◽  
Manije Dianat ◽  
Mohammad Mehdi Eskandari
Keyword(s):  
Hybrid Material ◽  
Catalytic Performance ◽  
Hybrid Catalyst ◽  
Inorganic Hybrid ◽  
Material Production ◽  
Inorganic Hybrid Material

A novel silica-based organic–inorganic hybrid catalyst was prepared, characterized and applied for the synthesis of pyrimido[4,5-b]quinolines.

scholarly journals Ultra-Deep Oxidative Desulfurization of Fuel with H2O2 Catalyzed by Mesoporous Silica-Supported Molybdenum Oxide Modified by Ce

2021 ◽  
Vol 11 (5) ◽  
pp. 2018
Author(s):  
Yang Chen ◽  
Qi Tian ◽  
Yongsheng Tian ◽  
Jiawei Cui ◽  
Guanghui Wang
Keyword(s):  
Mesoporous Silica ◽  
Molybdenum Oxide ◽  
Photoelectron Spectroscopy ◽  
Oxidative Desulfurization ◽  
Catalytic Performance ◽  
Fuel Oil ◽  
Reaction Products ◽  
X Ray ◽  
Operational Conditions ◽  
Apparent Activation Energies

A mesoporous silica-supported molybdenum oxide catalyst with a cerium(Ce) modifier was prepared by in situ synthesis and used in a hydrogen peroxide (H2O2) system for the desulfurization of dibenzothiophene (DBT), benzothiophene (BT), and 4,6-dimethyldibenzothiophene (4,6-DMDBT) fuel oils. The catalytic performance of the catalyst was studied. The catalyst was characterized by Fourier Transform Infra-Red(FT-IR), X-ray diffraction (XRD), Brunner−Emmet−Teller (BET), and X-ray Photoelectron Spectroscopy(XPS). The influences of m(catalyst)/m(fuel oil), v(H2O2)/v(fuel oil), reaction temperature, and reaction time were investigated. The catalyst had excellent catalytic oxidation desulfurization performance under moderate operational conditions. The catalytic performance was in the order DBT > 4,6-DMDBT > BT. The kinetic analysis results showed that the reaction was a pseudo first-order kinetics process and the apparent activation energies of DBT, BT, and 4,6-DMDBT were 46.67 kJ/mol, 56.23 kJ/mol, and 55.54 kJ/mol, respectively. The reaction products of DBT, BT, and 4,6-DMDBT were DBTO2, BTO2, and 4,6-DMDBTO2, respectively. The recycling experiments indicated that DBT, BT, and 4,6-DMDBT removal could still reach levels of 94.0%, 63.0%, and 77.9% after five cycles.

scholarly journals Extreme biomimetics: Preservation of molecular detail in centimeter-scale samples of biological meshes laid down by sponges

2019 ◽  
Vol 5 (10) ◽  
pp. eaax2805 ◽  
Author(s):  
Iaroslav Petrenko ◽  
Adam P. Summers ◽  
Paul Simon ◽  
Sonia Żółtowska-Aksamitowska ◽  
Mykhailo Motylenko ◽  
...  
Keyword(s):  
Hybrid Material ◽  
Triple Helix ◽  
Three Dimensional ◽  
Catalytic Performance ◽  
Fine Scale ◽  
Biomimetic Materials ◽  
Molecular Detail ◽  
Copper Electroplating ◽  
Nanoscale Features ◽  
Excellent Catalytic Performance

Fabrication of biomimetic materials and scaffolds is usually a micro- or even nanoscale process; however, most testing and all manufacturing require larger-scale synthesis of nanoscale features. Here, we propose the utilization of naturally prefabricated three-dimensional (3D) spongin scaffolds that preserve molecular detail across centimeter-scale samples. The fine-scale structure of this collagenous resource is stable at temperatures of up to 1200°C and can produce up to 4 × 10–cm–large 3D microfibrous and nanoporous turbostratic graphite. Our findings highlight the fact that this turbostratic graphite is exceptional at preserving the nanostructural features typical for triple-helix collagen. The resulting carbon sponge resembles the shape and unique microarchitecture of the original spongin scaffold. Copper electroplating of the obtained composite leads to a hybrid material with excellent catalytic performance with respect to the reduction of p-nitrophenol in both freshwater and marine environments.

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