Size-controlled PdO/graphene oxides and their reduction products with high catalytic activity

RSC Advances ◽  
2014 ◽  
Vol 4 (56) ◽  
pp. 29563-29570 ◽  
Author(s):  
Jingjing Lin ◽  
Tao Mei ◽  
Meijiao Lv ◽  
Chang'an Zhang ◽  
Zhenfeng Zhao ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Hydrazine Hydrate ◽  
Electrocatalytic Activity ◽  
Suzuki Reaction ◽  
High Catalytic Activity ◽  
Graphene Oxides ◽  
Highly Active ◽  
The Stability ◽  
Size Controlled ◽  
Better Than

Well-dispersed and size-controlled Pd/RGO with highly active catalysts was synthesized through reduction of PdO/GO with hydrazine hydrate and ammonia. The electrocatalytic activity and the stability of the as-prepared Pd/RGO are much better than those of commercial Pd/C catalysts for methanol electrooxidation and the Suzuki reaction.

Towards highly active heterogeneous catalysts via a sequential noncovalent bonding strategy

2021 ◽  
Author(s):  
Ruixue Wang ◽  
Ying Yue ◽  
Huiying Wei ◽  
Jinxin Guo ◽  
Yanzhao Yang
Keyword(s):  
Catalytic Activity ◽  
Heterogeneous Catalysts ◽  
High Catalytic Activity ◽  
Synthetic Route ◽  
Surface Ligands ◽  
Highly Active ◽  
Noncovalent Bonding ◽  
Excellent Stability

Here, a novel synthetic route of ceria-based nanocatalysts with high catalytic activity and excellent stability was constructed by utilizing function groups from surface ligands. The surface of ceria nanorods were...

Active phase of highly active Co3O4 catalyst for synthetic natural gas production

RSC Advances ◽  
2014 ◽  
Vol 4 (100) ◽  
pp. 57185-57191 ◽  
Author(s):  
Baowei Wang ◽  
Sihan Liu ◽  
Zongyuan Hu ◽  
Zhenhua Li ◽  
Xinbin Ma
Keyword(s):  
Catalytic Activity ◽  
Low Temperature ◽  
Natural Gas ◽  
Active Phase ◽  
Gas Production ◽  
High Catalytic Activity ◽  
Co Methanation ◽  
Synthetic Natural Gas ◽  
Highly Active ◽  
Catalytic Stability

Co3O4 nanoparticles showed high catalytic activity for low temperature CO methanation. CoO is the active phase of the catalyst. Pre-reduction treatment can improve catalytic stability.

Cascade catalysis of highly active bimetallic Au/Pd nanoclusters: structure–function relationship investigation using anomalous small-angle X-ray scattering and UV–Vis spectroscopy

2013 ◽  
Vol 46 (5) ◽  
pp. 1353-1360 ◽  
Author(s):  
Sylvio Haas ◽  
Robert Fenger ◽  
Edoardo Fertitta ◽  
Klaus Rademann
Keyword(s):  
Catalytic Activity ◽  
Structural Characteristics ◽  
High Surface ◽  
Volume Ratio ◽  
Single Type ◽  
High Catalytic Activity ◽  
Highly Active ◽  
Bimetallic Nanoclusters ◽  
Vis Spectroscopy ◽  
Cascade Catalysis

Recently, a so-called `crown-jewel' concept of preparation of Au/Pd-based colloidal nanoclusters has been reported [Zhang, Watanabe, Okumura, Haruta & Toshima (2011).Nat. Mater.11, 49–52]. Here, a different way of preparing highly active Au/Pd-based nanoclusters is presented. The origin of the increased activity of Au/Pd-based colloidal bimetallic nanoclusters was unclear up to now. However, it is, in general, accepted that in the nanometre range (1–100 nm) the cluster size, shape and composition affect the structural characteristics (e.g.lattice symmetry, unit cell), electronic properties (e.g.band gap) and chemical properties (e.g.catalytic activity) of a material. Hence, a detailed study of the relationship between the nanostructure of nanoclusters and their catalytic activity is presented here. The results indicate that a high surface-to-volume ratio of the nanoclusters combined with the presence of `both' Au and Pd isolated regions at the surface are crucial to achieve a high catalytic activity. A detailed structure elucidation directly leads to a mechanistic proposal, which indeed explains the higher catalytic activity of Au/Pd-based catalysts compared with pure metallic Au or Pd. The mechanism is based on cascade catalysis induced by a single type of nanoparticle with an intermixed surface of Au and Pd.

scholarly journals Synergistic Effects of Co3O4-CeO2 Nanoparticles towards Catalytic Oxidation of Aromatic Hydrocarbons: A Study in Association with Carbon Monoxide and Humidity

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Trung Dang-Bao ◽  
Hong Phuong Phan ◽  
Phung Anh Nguyen ◽  
Pham Phuong Trang Vo ◽  
Van Tien Huynh ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Catalytic Activity ◽  
Catalytic Oxidation ◽  
Synergistic Effects ◽  
Active Oxygen Species ◽  
High Dispersion ◽  
High Catalytic Activity ◽  
Impregnation Method ◽  
Temperature Programmed ◽  
The Stability

In this study, a series of Co3O4-CeO2 nanocomposites with various Co3O4 loading were fabricated by the impregnation method using cobalt(II) acetate as the cobalt precursor for the treatment of benzene, toluene, ethylbenzene, and xylene (BTEX). The as-prepared Co3O4-CeO2 nanocomposites were thoroughly characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Brumauer-Emmett-Teller (BET), hydrogen temperature-programmed reduction (H2-TPR), and temperature-programmed desorption (O2-TPD). The excellent reproduction of active oxygen species caused by the high dispersion of Co3O4 crystals on the CeO2 supports was established. In addition, the reduction peaks of Co3O4-CeO2 nanocomposites were found at much lower temperatures compared to pure CeO2, considering their unique redox property influencing on the high catalytic activity. Among the characterized materials, the 5.0 wt.% Co3O4 supported on CeO2 (5.0Co–Ce) was the best system for catalytic oxidation of xylene, along with excellent performances in the cases of benzene, ethylbenzene, and toluene. Its catalytic activity increased in the order: benzene < xylene < ethylbenzene < toluene . Furthermore, the addition of carbon monoxide (CO) as a coreactant permitted to improve the catalytic performances in such oxidations as well as the stability of as-prepared catalysts, even under humid conditions.

scholarly journals Study of Deactivation in Suzuki Reaction of Polymer-Stabilized Pd Nanocatalysts

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1653
Author(s):  
Linda Nikoshvili ◽  
Elena S. Bakhvalova ◽  
Alexey V. Bykov ◽  
Alexander I. Sidorov ◽  
Alexander L. Vasiliev ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Catalyst Deactivation ◽  
Phenylboronic Acid ◽  
Suzuki Reaction ◽  
Cross Coupling ◽  
Catalyst Stability ◽  
Separation Procedure ◽  
Amino Groups ◽  
Highly Active ◽  
Hydrophobic Nature

This work is addressed to the phenomenon of catalyst deactivation taking place during the repeated uses in the reaction of Suzuki-Miyaura (S-M) cross-coupling, which is widely applied in industry for C-C bond formation. Ligandless catalysts based on Pd(0) NPs supported on hyper-cross-linked polystyrene (HPS) of two types (non-functionalized and bearing tertiary amino groups) were studied in a model S-M reaction between 4-bromoanisole and phenylboronic acid. Synthesized catalysts were shown to be highly active under mild reaction conditions. HPS allows stabilization of Pd(0) NPs and prevents their agglomeration and detectable Pd leaching. However, the loss of catalytic activity was observed during recycling. The deactivation issue was assigned to the hydrophobic nature of non-functionalized HPS, which allowed a strong adsorption of cross-coupling product during the catalyst separation procedure. A thorough washing of Pd/HPS catalyst by hydrophobic solvent was found to improve to the big extent the observed catalytic activity, while the replacement of non-functionalized HPS by a one containing amino groups increased the catalyst stability at the expense of their activity.

Study on Bio-Fuels Drop Acid by [BSPy]HSO4 Catalytic Esterification

2013 ◽  
Vol 781-784 ◽  
pp. 2433-2437 ◽  
Author(s):  
Ai Hua Zhang ◽  
Zhi Hong Xiao ◽  
Liang Bo Zhang ◽  
Ru Kuan Liu ◽  
Wu Hong Zhong ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Acid Value ◽  
Esterification Reaction ◽  
Process Conditions ◽  
High Catalytic Activity ◽  
Brønsted Acidic Ionic Liquid ◽  
The Stability ◽  
Acid Esterification

Research on the synthesis of BrOnsted acidic ionic liquid by the method of solvent, the pyrolysis bio-fuel with cornus wisoniana oil drop acid esterification reaction, the catalyst dosage, reaction time and reaction temperature on the effects of the acid dropping and in the best optimization under the condition of the stability of the catalyst were investigated. The experimental results show that [BSPHSO4 with high catalytic activity, optimization of process conditions as follows: 1.2% of catalyst, reaction temperature 75 °C, reaction time of 70 min, acid value reduced to 2.0 mg KOH/g. By optimizing the cycle experiment, the stability of the catalyst performance is good, the catalytic activity is relatively stable.

Nanogold supported on manganese oxide doped alumina microspheres as a highly active and selective catalyst for CO oxidation in a H2-rich stream

2015 ◽  
Vol 51 (100) ◽  
pp. 17728-17731 ◽  
Author(s):  
Yu-Xin Miao ◽  
Wen-Cui Li ◽  
Qiang Sun ◽  
Lei Shi ◽  
Lei He ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation ◽  
Manganese Oxide ◽  
High Catalytic Activity ◽  
Selective Catalyst ◽  
Support Interaction ◽  
Highly Active

The exceptionally high catalytic activity for CO-PROX reaction is due to the Au–support interaction and the unique reducibility of the support.

New Modeling of AgFeNi2S4-Graphene-TiO2 Ternary Nanocomposite with Chelate Compounds and Its Photocatalytic Reduction of CO2

2021 ◽  
Author(s):  
Zambaga Otgonbayar ◽  
Chong Hun Jung ◽  
Oh Won-Chun
Keyword(s):  
Catalytic Activity ◽  
Citric Acid ◽  
Solvothermal Method ◽  
High Catalytic Activity ◽  
Photogenerated Electrons ◽  
Methanol Formation ◽  
Nano Material ◽  
Chelate Compounds ◽  
The Stability ◽  
Reduction Of Co2

Abstract Herein, we synthesized the chalcogenide-quaternary nanocomposite loaded Graphene-based ternary photocatalyst via a modified solvothermal method. The preparation of quaternary nanocomposite was based on metallic citrate polymerization which used ethylene glycol (C2H6O2) and citric acid (C6H8O7) as chelate cations. The morphology and electrochemical properties of the as-prepared nano-material investigated by using a physical characterization equipment. Each result showed that the ternary photocatalyst was successfully synthesized and showed the low recombination rate of photogenerated electrons and holes, which defined the catalytic activity of the photocatalyst for CO2 evolution into hydrocarbon fuels under light irradiation. In addition, the stability and reusability of the photocatalyst were analyzed by a 6-times cycling test without loss of methanol formation by CO2 evolution. The graphene-based ternary photocatalyst offers a new nanomaterial with a new-model that protects the environment by showing high catalytic activity in reducing CO2 to methanol.

scholarly journals Simple synthesis of sub-nanometer Pd clusters: High catalytic activity of Pd/PEG-PNIPAM in Suzuki reaction

2017 ◽  
Vol 38 (4) ◽  
pp. 651-657 ◽  
Author(s):  
Zhe Chen ◽  
Yu Liang ◽  
Da-Shuang Jia ◽  
Zhi-Min Cui ◽  
Wei-Guo Song
Keyword(s):  
Catalytic Activity ◽  
Suzuki Reaction ◽  
Simple Synthesis ◽  
High Catalytic Activity ◽  
Pd Clusters

MCM-41-Immobilised Nitrogen and Sulfur Mixed Tridentate Palladium(0) Complex: A Highly Efficient and Recyclable Catalyst for the Suzuki Reaction of Aryl Bromides in Air

2017 ◽  
Vol 41 (3) ◽  
pp. 186-191 ◽  
Author(s):  
Dayi Liu ◽  
Pingping Wang ◽  
Jingting Ai ◽  
Mingzhong Cai
Keyword(s):  
Hydrazine Hydrate ◽  
Active Catalyst ◽  
Suzuki Reaction ◽  
Significant Loss ◽  
Recyclable Catalyst ◽  
The Novel ◽  
Highly Efficient ◽  
Highly Active ◽  
Aryl Bromides ◽  
Mcm 41

The novel MCM-41-immobilised nitrogen and sulfur mixed tridentate palladium(0) complex [MCM-41-2N,S-Pd(0)] was prepared from 3-(2-aminoethylamino)propyltrimethoxysilane by immobilisation on MCM-41, followed by reaction with thiophene-2-carboxaldehyde and PdCl2 and then reduction with hydrazine hydrate. This phosphine-free heterogeneous palladium(0) complex was a highly active catalyst for the Suzuki reaction of aryl bromides in air and could be recycled at least 8 times without significant loss of activity.

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