Exposure to air boosts CuAAC reactions catalyzed by PEG-stabilized Cu nanoparticles

2017 ◽  
Vol 53 (39) ◽  
pp. 5384-5387 ◽  
Author(s):  
Fangyu Fu ◽  
Angel Martinez ◽  
Changlong Wang ◽  
Roberto Ciganda ◽  
Luis Yate ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Aerobic Oxidation ◽  
Cu Nanoparticles

The catalytic activity of Cu(0) NPs is boosted upon aerobic oxidation, forming Cu2O NPs, and further improved on an SBA-15 support.

The design and catalytic performance of molybdenum active sites on an MCM-41 framework for the aerobic oxidation of 5-hydroxymethylfurfural to 2,5-diformylfuran

2019 ◽  
Vol 9 (3) ◽  
pp. 811-821 ◽  
Author(s):  
Zhao-Meng Wang ◽  
Li-Juan Liu ◽  
Bo Xiang ◽  
Yue Wang ◽  
Ya-Jing Lyu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Active Sites ◽  
Aerobic Oxidation ◽  
Catalytic Performance ◽  
Mcm 41

The catalytic activity decreases as –(SiO)3Mo(OH)(O) > –(SiO)2Mo(O)2 > –(O)4–MoO.

On the selective aerobic oxidation of benzyl alcohol with Pd/Au-nanoparticles in batch and flow

2014 ◽  
Vol 3 (1) ◽  
pp. 99-110 ◽  
Author(s):  
Hannes Alex ◽  
Norbert Steinfeldt ◽  
Klaus Jähnisch ◽  
Matthias Bauer ◽  
Sandra Hübner
Keyword(s):  
Catalytic Activity ◽  
Benzyl Alcohol ◽  
Aerobic Oxidation ◽  
X Ray ◽  
X Ray Scattering ◽  
Oxidation Of Benzyl Alcohol ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Selective Aerobic Oxidation

AbstractNanoparticles (NP) have specific catalytic properties, which are influenced by parameters like their size, shape, or composition. Bimetallic NPs, composed of two metal elements can show an improved catalytic activity compared to the monometallic NPs. We, herein, report on the selective aerobic oxidation of benzyl alcohol catalyzed by unsupported Pd/Au and Pd NPs at atmospheric pressure. NPs of varying compositions were synthesized and characterized by UV/Vis spectroscopy, transmission electron microscopy (TEM), and small-angle X-ray scattering (SAXS). The NPs were tested in the model reaction regarding their catalytic activity, stability, and recyclability in batch and continuous procedure. Additionally, in situ extended X-ray absorption fine structure (EXAFS) measurements were performed in order to get insight in the process during NP catalysis.

A novel copper(ii)–lanthanum(iii) metal organic framework as a selective catalyst for the aerobic oxidation of benzylic hydrocarbons and cycloalkenes

2016 ◽  
Vol 6 (11) ◽  
pp. 3727-3736 ◽  
Author(s):  
P. Cancino ◽  
A. Vega ◽  
Andrea Santiago-Portillo ◽  
Sergio Navalon ◽  
Mercedes Alvaro ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Metal Organic Framework ◽  
Aerobic Oxidation ◽  
Selective Catalyst ◽  
Pyridinedicarboxylic Acid ◽  
Metal Organic ◽  
Organic Framework

The synthesis and catalytic activity of a novel heteronuclear CuII and LaIII metal organic framework (MOF) having pyridinedicarboxylic acid (CuLa-MOF) is reported.

scholarly journals Engineering Active Sites in Reduced Graphene Oxide: Tuning the Catalytic Activity for Aerobic Oxidation

2019 ◽  
Vol 7 (19) ◽  
pp. 15948-15956 ◽  
Author(s):  
Juan C. Espinosa ◽  
Mercedes Álvaro ◽  
Amarajothi Dhakshinamoorthy ◽  
Sergio Navalón ◽  
Hermenegildo García
Keyword(s):  
Graphene Oxide ◽  
Catalytic Activity ◽  
Reduced Graphene Oxide ◽  
Active Sites ◽  
Aerobic Oxidation ◽  
Reduced Graphene

scholarly journals Aerobic Oxidation of 5-Hydroxymethylfurfural over Ag Nanoparticle Catalysts Stabilized by Polyvinylpyrrolidone with Different Molecular Weights

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1624
Author(s):  
Haian Xia ◽  
Jiahuan An ◽  
Weizi Zhang
Keyword(s):  
Catalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Catalytic Properties ◽  
Aerobic Oxidation ◽  
Ag Nps ◽  
Oxidation Activity ◽  
X Ray ◽  
Remarkable Effect ◽  
Molecular Weights ◽  
Metal Support Interaction

The metal–support interaction (MSI) has a remarkable effect on the catalytic properties, but how to precisely modulate its degree remains a huge challenge. Herein, polyvinylpyrrolidone (PVP) with three different molecular weights (MWs) (24, 58, and 130 kDa) was used as a capping agent to fabricate Ag nanoparticles (NPs) supported on ZrO2. The physiochemical properties of the catalysts were characterized by X-ray diffraction (XRD), Transmission Electron Microscope (TEM), X-ray Photoelectron Spectroscopy (XPS), and Fourier transform infrared (FT-IR) techniques. The impacts of MSI on the catalytic activity and reaction kinetics for aerobic oxidation of 5-hydroxymethylfurfural (HMF) were investigated. The results showed that the introduction of PVP with various MWs could efficiently tailor the interfacial interactions and charge transfers (CT) among PVP, the support, and Ag NPs, thereby affecting the oxidation activity of HMF. The turnover number (TON) for HMF oxidation decreases in the order of unsupported colloidal Ag clusters > Ag/ZrO2 (58,000) > Ag/ZrO2 (130,000) > Ag/ZrO2 (24,000) > Ag/ZrO2. The reason for this large difference in the catalytic activity for HMF oxidation is that various MWs of PVP result in a change of MSI, thereby facilitating CT from PVP to Ag metal sites. This study offers a new strategy for modulating MSI by varying the MW of capping agents, thereby tuning the catalytic properties in the oxidation of HMF.

Selective aerobic allylic oxidation of α-pinene catalyzed by metalloporphyrins in the absence of solvents and additives

2019 ◽  
Vol 43 (9-10) ◽  
pp. 419-425 ◽  
Author(s):  
Huanhuan Dong ◽  
Shichao Xu ◽  
Jing Wang ◽  
Yuxiang Chen ◽  
Liangwu Bi ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Reaction Time ◽  
Flow Rate ◽  
Catalyst Concentration ◽  
Aerobic Oxidation ◽  
Oxygen Flow Rate ◽  
Oxidation Products ◽  
Allylic Oxidation ◽  
Temperature Reaction ◽  
Reaction Conditions

Selective aerobic oxidation of α-pinene to high-value products is a major challenge in chemistry. Metalloporphyrins are proved to be selective catalysts for aerobic oxidation of simple hydrocarbons. Herein, we extend this method to more complex substrates using metallodeuteroporphyrins as model catalysts. It was found that the oxidation occurs mainly on the C=C and allylic C–H bonds of α-pinene influenced by the reaction temperature, reaction time, catalyst concentration, and oxygen flow rate. Allylic C–H oxidation products are obtained with a maximum selectivity value of 78.4% using the following reaction conditions: 105°C, 7 h, 5 ppm, and 60 mL/min. The influence of the metal nuclei of the metallodeuteroporphyrins on this reaction is also investigated. It was found that metallodeuteroporphyrins with Fe3+ as the metal nucleus exhibit the highest catalytic activity.

scholarly journals 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

2019 ◽  
Vol 9 (23) ◽  
pp. 6659-6668 ◽  
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.

scholarly journals Novel Effect of Zinc Nitrate/Vanadyl Oxalate for Selective Catalytic Oxidation of α-Hydroxy Esters to α-Keto Esters with Molecular Oxygen: An In Situ ATR-IR Study

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1281 ◽  
Author(s):  
Yongwei Ju ◽  
Zhongtian Du ◽  
Chuhong Xiao ◽  
Xingfei Li ◽  
Shuang Li
Keyword(s):  
Catalytic Activity ◽  
Catalytic Oxidation ◽  
Molecular Oxygen ◽  
Aerobic Oxidation ◽  
Value Added ◽  
Attenuated Total Reflection ◽  
Reaction Conditions ◽  
Keto Esters ◽  
Selective Catalytic Oxidation ◽  
Hydroxy Esters

Selective oxidation of α-hydroxy esters is one of the most important methods to prepare high value-added α-keto esters. An efficient catalytic system consisting of Zn(NO3)2/VOC2O4 is reported for catalytic oxidation of α-hydroxy esters with molecular oxygen. Up to 99% conversion of methyl DL-mandelate or methyl lactate could be facilely obtained with high selectivity for its corresponding α-keto ester under mild reaction conditions. Zn(NO3)2 exhibited higher catalytic activity in combination with VOC2O4 compared with Fe(NO3)3 and different nitric oxidative gases were detected by situ attenuated total reflection infrared (ATR-IR) spectroscopy. UV-vis and ATR-IR results indicated that coordination complex formed in Zn(NO3)2 in CH3CN solution was quite different from Fe(NO3)3; it is proposed that the charge-transfer from Zn2+ to coordinated nitrate groups might account for the generation of different nitric oxidative gases. The XPS result indicate that nitric oxidative gas derived from the interaction of Zn(NO3)2 with VOC2O4 could be in favor of oxidizing VOC2O4 to generate active vanadium (V) species. It might account for different catalytic activity of Zn(NO3)2 or Fe(NO3)3 combined with VOC2O4. This work contributes to further development of efficient aerobic oxidation under mild reaction conditions.

Theoretical Investigation of the Heterojunction Effect on the Catalytic Activity and Selectivity of an Au@NiO Core–Shell Catalyst in Aerobic Oxidation

2020 ◽  
Vol 124 (31) ◽  
pp. 17039-17047
Author(s):  
Akihide Hayashi ◽  
Yoshinori Ato ◽  
Kohei Tada ◽  
Hiroaki Koga ◽  
Takashi Kawakami ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Theoretical Investigation ◽  
Aerobic Oxidation ◽  
Core Shell
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