Vanadium-Chromium Oxide: Effective Catalysts for Ammoxidation of 3-Picoline

Bulk vanadium-chromium oxide (VCrO) catalyst was prepared and characterized by N2 adsorption, XRD, NH3-TPD, H2-TPR, and Raman spectroscopy. XRD and Raman results showed that the VCrO catalyst was a kind of VV-CrIII composite oxide mainly consisted of crystalline V2O5 and CrVO4-Ⅲ (orthorhombic). NH3-TPD and H2-TPR results revealed that this catalyst had negligible surface acidity, and was easily reduced due to the formation of CrVO4-Ⅲ. Their catalytic activity was evaluated in the ammoxidation of 3-picoline to nicotinonitrile. Catalytic results showed that the bulk VCrO catalyst was highly active and selective; the nicotinonitrile selectivity and yield was up to 96.1%, 88.2% respectively at atmospheric pressure and 360 °C. The high selectivity was related closely to the low surface acidity of the catalyst.

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Catalytic Activity of Dehydrogenation of Methanol to MF over Cu/MCM-41 and Cu-ZnO/MCM-41 Prepared by Impregnation and Grinding

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.396-398.730 ◽

2011 ◽

Vol 396-398 ◽

pp. 730-733

Author(s):

Guo Ru Li ◽

Gong Li ◽

Shu Xi Zhou ◽

Hui Juan Tong

Keyword(s):

Catalytic Activity ◽

Atmospheric Pressure ◽

Molecular Sieves ◽

Conversion Rate ◽

Methyl Formate ◽

Methanol Conversion ◽

N2 Adsorption ◽

Flow Microreactor ◽

Adsorption Desorption ◽

Mcm 41

Abstract. Using MCM-41 molecular sieves as the support, Cu-ZnO/MCM-41 and Cu/MCM-41 catalysts were prepared by impregnation and grinding. The catalysts were characterized by XRD, N2 adsorption-desorption and TPR methods. The catalytic activity of the dehydrogenation of methanol to methyl formate (MF) was evaluated using the flow microreactor under atmospheric pressure. According to the results, the catalyst prepared by impregnation had a better selectivity for the MF, but a lower methanol conversion rate. However, the product's selectivity could be improved by adding ZnO additive while the methanol conversion rate was reduced. For Cu/MCM-41 prepared by impregnation and grinding, the methanol conversion rate was 20.18% and 24.13% respectively at 250°C and the MF selectivity was 73.75% and 67.35% respectively. Likewise for Cu-ZnO/MCM-41 prepared by impregnation and grinding, the methanol conversion rate was 15.28% and 18.83% respectively at 250°C and the MF selectivity was 81.31% and 75.32% respectively.

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Deactivation of arenetitanium(II) bromoalane complexes in the cyclotrimerization of butadiene

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19862751 ◽

1986 ◽

Vol 51 (12) ◽

pp. 2751-2759 ◽

Cited By ~ 2

Author(s):

Jindřich Poláček ◽

Helena Antropiusová ◽

Lidmila Petrusová ◽

Karel Mach

Keyword(s):

Catalytic Activity ◽

Catalytic System ◽

Model System ◽

Highly Active ◽

Catalytic Stability

The C6H6.Ti(II)(AlBr4)2 (Ib) catalyst deactivates during the butadiene cyclotrimerization to give a solid containing all titanium (mostly as TiBr3) and a mixture of AlBr3 and RAlBr2 compounds dissolved in benzene. The residual cationic catalytic activity of the deactivated Ib system is due to presence of AlBr3. In contrast to TiCl3, the deactivated Ib system and the model system TiBr3 + AlBr3 are not activated by the addition of EtAlCl2 in the presence of butadiene: the highly active benzenetitanium(II) system is re-constituted only after reduction of TiBr3 with Et3Al followed by the addition of EtAlCl2. The addition of Et2AlBr to Ib accelerates the deactivation of the system. Deactivation products of this system contain mainly Ti(II) species which forms benzenetitanium(II) catalytic system after addition of EtAlCl2. All the EtAlCl2 reactivated systems produce (Z, E, E)-1,5,9-cyclododecatriene with high catalytic stability and considerable selectivity (>90%). This behaviour points to the catalysis by benzenetitanium(II) chloroalane complexes containing only low amount of bromine atoms and ethyl groups.

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Highly Dispersed Pd Species Supported on CeO2 Catalyst for Lean Methane Combustion: The Effect of the Occurrence State of Surface Pd Species on the Catalytic Activity

Catalysts ◽

10.3390/catal11070772 ◽

2021 ◽

Vol 11 (7) ◽

pp. 772

Author(s):

Yanxiong Liu ◽

Changhua Hu ◽

Longchun Bian

Keyword(s):

Catalytic Activity ◽

Oxygen Vacancies ◽

Methane Combustion ◽

Pd Nanoparticles ◽

High Concentration ◽

Ch4 Combustion ◽

Highly Active ◽

Δ Phase ◽

Occurrence State ◽

Comprehensive Characterization

The correlation between the occurrence state of surface Pd species of Pd/CeO2 for lean CH4 combustion is investigated. Herein, by using a reduction-deposition method, we have synthesized a highly active 0.5% PdO/CeO2-RE catalyst, in which the Pd nanoparticles are evenly dispersed on the CeO2 nanorods CeO2-R. Based on comprehensive characterization, we have revealed that the uniformly dispersed Pd nanoparticles with a particle size distribution of 2.3 ± 0.6 nm are responsible for the generation of PdO and PdxCe1−xO2−δ phase with –Pd2+–O2−–Ce4+– linkage, which can easily provide oxygen vacancies and facilitate the transfer of reactive oxygen species between the CeO2-R and Pd species. As a consequence, the remarkable catalytic activity of 0.5% Pd/CeO2-RE is related to the high concentration of PdO species on the surface of the catalyst and the synergistic interaction between the Pd species and the CeO2 nanorod.

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Ring-Opening Copolymerization of Cyclohexene Oxide and Cyclic Anhydrides Catalyzed by Bimetallic Scorpionate Zinc Catalysts

Polymers ◽

10.3390/polym13101651 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1651

Author(s):

Felipe de la Cruz-Martínez ◽

Marc Martínez de Sarasa Buchaca ◽

Almudena del Campo-Balguerías ◽

Juan Fernández-Baeza ◽

Luis F. Sánchez-Barba ◽

...

Keyword(s):

Catalytic Activity ◽

Reaction Mechanism ◽

Catalytic System ◽

Phthalic Anhydride ◽

Ring Opening ◽

High Selectivity ◽

Zinc Complexes ◽

Cyclohexene Oxide ◽

Reaction Conditions ◽

Cyclic Anhydrides

The catalytic activity and high selectivity reported by bimetallic heteroscorpionate acetate zinc complexes in ring-opening copolymerization (ROCOP) reactions involving CO2 as substrate encouraged us to expand their use as catalysts for ROCOP of cyclohexene oxide (CHO) and cyclic anhydrides. Among the catalysts tested for the ROCOP of CHO and phthalic anhydride at different reaction conditions, the most active catalytic system was the combination of complex 3 with bis(triphenylphosphine)iminium as cocatalyst in toluene at 80 °C. Once the optimal catalytic system was determined, the scope in terms of other cyclic anhydrides was broadened. The catalytic system was capable of copolymerizing selectively and efficiently CHO with phthalic, maleic, succinic and naphthalic anhydrides to afford the corresponding polyester materials. The polyesters obtained were characterized by spectroscopic, spectrometric, and calorimetric techniques. Finally, the reaction mechanism of the catalytic system was proposed based on stoichiometric reactions.

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Fabrication of gold nanostructure decorated polystyrene hybrid nanosystems via poly(L-DOPA) and their applications in surface-enhanced Raman Spectroscopy (SERS), and catalytic activity

Colloids and Surfaces A Physicochemical and Engineering Aspects ◽

10.1016/j.colsurfa.2021.126654 ◽

2021 ◽

Vol 622 ◽

pp. 126654

Author(s):

Baris Calis ◽

Mehmet Yilmaz

Keyword(s):

Raman Spectroscopy ◽

Catalytic Activity ◽

Surface Enhanced Raman Spectroscopy ◽

Surface Enhanced ◽

Surface Enhanced Raman ◽

Gold Nanostructure ◽

Hybrid Nanosystems

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A new highly active La2O3–CuO–MgO catalyst for the synthesis of cumyl peroxide by catalytic oxidation

RSC Advances ◽

10.1039/d1ra00176k ◽

2021 ◽

Vol 11 (21) ◽

pp. 12532-12542

Author(s):

HanShuang Liu ◽

KaiJun Wang ◽

XiaoYan Cao ◽

JiaXin Su ◽

Zhenggui Gu

Keyword(s):

Catalytic Activity ◽

Catalytic Oxidation ◽

Highly Active

The La2O3–CuO–MgO catalyst acts on the oxidation of cumene and shows excellent catalytic activity through the coordination of surface and interior.

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A monovacant heteropolytungstate-incorporated trimeric carbonyl rhenium cluster, [(AsW11O39){Re(CO)3}3(μ3-OH)(μ2-OH)]6−: synthesis, structure and catalytic properties

RSC Advances ◽

10.1039/c4ra03532a ◽

2014 ◽

Vol 4 (55) ◽

pp. 28848-28851 ◽

Cited By ~ 9

Author(s):

Yanhui Zhang ◽

Dongdi Zhang ◽

Zhiyuan Huo ◽

Pengtao Ma ◽

Jingyang Niu ◽

...

Keyword(s):

Catalytic Activity ◽

High Selectivity ◽

Catalytic Properties ◽

The Novel ◽

Rhenium Cluster

The novel undecatungstoarsenate-supported carbonyl rhenium derivative exhibits prominent catalytic activity and high selectivity in the cycloaddition of epoxides.

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Effect of surface acidity on the catalytic activity and deactivation of supported sulfonic acids during dehydration of methanol to DME

New Journal of Chemistry ◽

10.1039/d0nj00229a ◽

2020 ◽

Vol 44 (39) ◽

pp. 16810-16820

Author(s):

Rosanna Viscardi ◽

Vincenzo Barbarossa ◽

Daniele Mirabile Gattia ◽

Raimondo Maggi ◽

Giovanni Maestri ◽

...

Keyword(s):

Catalytic Activity ◽

Sulfonic Acid ◽

Water Resistance ◽

Surface Acidity ◽

Acid Catalyst ◽

Acid Sites ◽

Sulfonic Acids ◽

Effect Of Surface

Superiorty of the supported sulfonic acid catalyst in terms of the water resistance and efficiency of the acid sites compared to the commercial reference.

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