scholarly journals Ultra-Small Pd(0) Nanoparticles into a Designed Semisynthetic Lipase: An Efficient and Recyclable Heterogeneous Biohybrid Catalyst for the Heck Reaction under Mild Conditions

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2358 ◽  
Author(s):  
David Lopez-Tejedor ◽  
Blanca de las Rivas ◽  
Jose M. Palomo
Keyword(s):  
Catalytic Activity ◽  
Protein Structure ◽  
Heck Reaction ◽  
Catalytic Performance ◽  
Reducing Agent ◽  
Chemically Modified ◽  
Mild Conditions ◽  
In Situ Formation ◽  
Geobacillus Thermocatenulatus

A novel heterogeneous enzyme-palladium (Pd) (0) nanoparticles (PdNPs) bionanohybrid has been synthesized by an efficient, green, and straightforward methodology. A designed Geobacillus thermocatenulatus lipase (GTL) variant genetically and then chemically modified by the introduction of a tailor-made cysteine-containing complementary peptide- was used as the stabilizing and reducing agent for the in situ formation of ultra-small PdNPs nanoparticles embedded on the protein structure. This bionanohybrid was an excellent catalyst in the synthesis of trans-ethyl cinnamate by Heck reaction at 65 °C. It showed the best catalytic performance in dimethylformamide (DMF) containing 10–25% of water as a solvent but was also able to catalyze the reaction in pure DMF or with a higher amount of water as co-solvent. The recyclability and stability were excellent, maintaining more than 90% of catalytic activity after five cycles of use.

The Effect of Ni Precursor Salts on Diatomite Supported Ni-Mg Catalysts in Methanation of CO2

2021 ◽  
Vol 1016 ◽  
pp. 1417-1422
Author(s):  
Chao Sun ◽  
Jugoslav Krstic ◽  
Vojkan Radonjic ◽  
Miroslav Stankovic ◽  
Patrick da Costa
Keyword(s):  
Catalytic Activity ◽  
Atmospheric Pressure ◽  
Textural Properties ◽  
Catalytic Performance ◽  
Nickel Salt ◽  
Nitrate Salt ◽  
Efficient Catalyst ◽  
Mild Conditions ◽  
The Difference ◽  
Supported Ni

This study is aimed to investigate the effect of Ni precursor salts on the properties (textural, phase-structural, reducibility, and basicity), and catalytic performance of diatomite supported Ni-Mg catalyst in methanation of CO2. The NiMg/D-X catalysts derived from various nickel salts (X = S-sulfamate, N-nitrate or A-acetate) were synthesized by the precipitation-deposition (PD) method. The catalysts were characterized by N2-physisorption, XRD, TPR-H2, and TPD-CO2 techniques. The different catalytic activity (conversion) and selectivity, observed in CO2 methanation carried out under relatively mild conditions (atmospheric pressure; temperatures: 250-450 °C) are related and explained by the difference in textural properties, metallic Ni-crystallite size, reducibility, and basicity of studied catalysts. The results showed that catalyst derived from Ni-nitrate salt (NiMg/D-N) is more suitable for the preparation of efficient catalyst for CO2 methanation than its counterparts derived from sulfamate (NiMg/D-S) or acetate (NiMg/D-A) nickel salt. The NiMg/D-N catalyst showed the highest specific surface area and total basicity, and the best catalytic performance with CO2 conversion of 63.3 % and CH4 selectivity of 80.9 % at 450 °C.

scholarly journals Catalytic Activity of Polynuclear vs. Dinuclear Aroylhydrazone Cu(II) Complexes in Microwave-Assisted Oxidation of Neat Aliphatic and Aromatic Hydrocarbons

Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 47 ◽  
Author(s):  
Manas Sutradhar ◽  
Tannistha Barman ◽  
Armando Pombeiro ◽  
Luísa Martins
Keyword(s):  
Catalytic Activity ◽  
Aromatic Hydrocarbons ◽  
Catalytic Performance ◽  
Antiproliferative Agents ◽  
One Dimensional ◽  
X Ray ◽  
X Ray Crystallography ◽  
Mild Conditions ◽  
Microwave Assisted ◽  
Aliphatic And Aromatic Hydrocarbons

One-dimensional (1D) polynuclear Cu(II) complex (1) derived from (5-bromo-2-hydroxybenzylidene)-2-hydroxybenzohydrazide (H2L) is synthesized and characterized by elemental analysis, IR spectroscopy, ESI-MS, and single crystal X-ray crystallography. Its catalytic performance towards the solvent-free microwave-assisted peroxidative oxidation of aliphatic and aromatic hydrocarbons under mild conditions is compared with that of dinuclear Cu(II) complexes (2 and 3) of the same ligand, previously reported as antiproliferative agents. Polymer 1 exhibits the highest activity, either for the oxidation of cyclohexane (leading to overall yields, based on the alkane, of up to 39% of cyclohexanol and cyclohexanone) or towards the oxidation of toluene (selectively affording benzaldehyde up to a 44% yield), after 2 or 2.5 h of irradiation at 80 or 50 °C, respectively.

Synthesis and catalytic performance of graphene oxide-Au nanorings composites

2019 ◽  
Vol 12 (03) ◽  
pp. 1950028 ◽  
Author(s):  
Tong Shen ◽  
Zhong Li ◽  
Yue Jiang ◽  
Zai-Gang Luo
Keyword(s):  
Graphene Oxide ◽  
Catalytic Activity ◽  
Rate Constant ◽  
Sodium Borohydride ◽  
Catalytic Performance ◽  
Hybrid Structure ◽  
In Situ Synthesis ◽  
Galvanic Replacement ◽  
Hybrid Nanomaterial

A simple and facile method is described for the in situ synthesis of graphene oxide-Ag nanoplates (GO-AgNPs) hybrid structure and then served as sacrificial templates for producing graphene oxide-Au nanorings (GO-AuNRs) by galvanic replacement taken place on the GO surface. The catalytic activity of the resulting hybrid nanomaterial has been investigated for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) with sodium borohydride (NaBH4). The results showed that the rate constant of GO-AuNRs nanomaterials was 0.205[Formula: see text]min[Formula: see text] and the samples showed significant enhancement in catalytic activity.

In situ formation of highly active Ni–Fe based oxygen-evolving electrocatalysts via simple reactive dip-coating

2017 ◽  
Vol 5 (22) ◽  
pp. 11009-11015 ◽  
Author(s):  
Guofa Dong ◽  
Ming Fang ◽  
Jianshuo Zhang ◽  
Renjie Wei ◽  
Lei Shu ◽  
...  
Keyword(s):  
Oxygen Evolution ◽  
State Of The Art ◽  
Catalytic Performance ◽  
Dip Coating ◽  
Highly Active ◽  
Coating Method ◽  
In Situ Formation ◽  
Dip Coating Method ◽  
Oxygen Evolving

An extremely simple in situ reactive dip-coating method is developed to prepare Ni–Fe based electrocatalysts with good catalytic performance on oxygen evolution comparable to those of state-of-the art precious catalysts.

An efficient CO2 fixation reaction with epoxides catalysed by in situ formed blue vanadium catalyst from dioxovanadium(+5) complex: moisture enhanced and atmospheric oxygen retarded catalytic activity

2020 ◽  
Vol 44 (6) ◽  
pp. 2547-2554 ◽  
Author(s):  
Rakhimoni Borah ◽  
Naranarayan Deori ◽  
Sanfaori Brahma
Keyword(s):  
Carbon Dioxide ◽  
Catalytic Activity ◽  
Co2 Fixation ◽  
Atmospheric Oxygen ◽  
Carbon Dioxide Fixation ◽  
Vanadium Catalyst ◽  
Cyclic Carbonates ◽  
Mild Conditions ◽  
Fixation Reaction

In situ formed vanadium(+4) species catalyzed carbon dioxide fixation reaction, leading to 99% conversion of epoxides to cyclic carbonates under mild conditions is reported here, along with the study on the in situ formed catalyst to some extent.

Self-reducing asymmetric polymer membrane for in situ formation and containment of noble metal nanocatalysts

2015 ◽  
Vol 17 (8) ◽  
pp. 4157-4161 ◽  
Author(s):  
Sankararao Chappa ◽  
Rakesh N. Shinde ◽  
Ashok K. Pandey
Keyword(s):  
Catalytic Activity ◽  
Noble Metal ◽  
Redox Reactions ◽  
Polymer Membrane ◽  
Good Catalytic Activity ◽  
In Situ Formation ◽  
Inorganic And Organic

Highly stable metal nanocatalysts formed in self-reducing asymmetric polymer membrane exhibit good catalytic activity in inorganic and organic redox reactions.

Highly reduced molybdophosphate as a noble-metal-free catalyst for the reduction of chromium using formic acid as a reducing agent

2015 ◽  
Vol 3 (11) ◽  
pp. 6019-6027 ◽  
Author(s):  
Kaining Gong ◽  
Weijie Wang ◽  
Jinshuang Yan ◽  
Zhangang Han
Keyword(s):  
Formic Acid ◽  
Noble Metal ◽  
Catalytic Performance ◽  
Reducing Agent ◽  
Metal Free ◽  
Mild Conditions

Cobalt-containing polyoxometalates exhibit catalytic performance for toxic chromium(vi) reduction using formic acid under mild conditions.

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