Mosaic structure effect and superior catalytic performance of AgBr/Ag2MoO4 composite materials

RSC Advances ◽  
2016 ◽  
Vol 6 (97) ◽  
pp. 94771-94779 ◽  
Author(s):  
Jing-Yu Zhang ◽  
Yi Lu ◽  
Jin-Ku Liu ◽  
Hao Jiang

The research focused on mosaic style AgBr–Ag2MoO4 composite materials prepared by in situ composite method. The catalytic efficiency enhanced 149 times compared to pure Ag2MoO4. The success of instant catalysis owed to the mosaic structure effect.

Author(s):  
Ricci Underhill ◽  
Mark Douthwaite ◽  
Richard J. Lewis ◽  
Peter J. Miedziak ◽  
Robert D. Armstrong ◽  
...  

AbstractLow temperature oxidation of alcohols over heterogeneous catalysts is exceptionally challenging, particularly under neutral conditions. Herein, we report on an efficient, base-free method to oxidise glycerol over a 0.5%Pd-0.5%Fe/SiO2 catalyst at ambient temperature in the presence of gaseous H2 and O2. The exceptional catalytic performance was attributed to the in situ formation of highly reactive surface-bound oxygenated species, which promote the dehydrogenation on the alcohol. The PdFe bimetallic catalyst was determined to be significantly more active than corresponding monometallic analogues, highlighting the important role both metals have in this oxidative transformation. Fe leaching was confirmed to occur over the course of the reaction but sequestering experiments, involving the addition of bare carbon to the reactions, confirmed that the reaction was predominantly heterogeneous in nature. Investigations with electron paramagnetic resonance spectroscopy suggested that the reactivity in the early stages was mediated by surface-bound reactive oxygen species; no homogeneous radical species were observed in solution. This theory was further evidenced by a direct H2O2 synthesis study, which confirmed that the presence of Fe in the bimetallic catalyst neither improved the synthesis of H2O2 nor promoted its decomposition over the PdFe/SiO2 catalyst.


2017 ◽  
Vol 4 (7) ◽  
pp. 1173-1181 ◽  
Author(s):  
Haidong Yang ◽  
Sha Luo ◽  
Yun Bao ◽  
Yutong Luo ◽  
Jun Jin ◽  
...  

The ultrathin Ni70Fe30LDH nanosheets were successfullyin situgrown on anodic polarized copper foil, denoted as u-Ni70Fe30LDHs/a-CF. Benefiting from the ultrathin nanosheet structure, the catalyst exhibits remarkable catalytic performance for OER in 1 M KOH solution.


RSC Advances ◽  
2016 ◽  
Vol 6 (6) ◽  
pp. 5016-5023 ◽  
Author(s):  
Bharat Baruah

Silver nanoparticles were immobilized on fibers to create composite materials. The composites are shown to be efficient heterogeneous catalyst with very good recyclability. These composite materials are also proven to be good SERS substrates.


Rare Metals ◽  
2009 ◽  
Vol 28 (4) ◽  
pp. 405-411 ◽  
Author(s):  
Yong Xie ◽  
Changming Liu ◽  
Yanbo Zhai ◽  
Kai Wang ◽  
Xuedong Ling

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2358 ◽  
Author(s):  
David Lopez-Tejedor ◽  
Blanca de las Rivas ◽  
Jose M. Palomo

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.


2010 ◽  
Vol 24 (31) ◽  
pp. 6115-6127 ◽  
Author(s):  
MARYAMOSSADAT BOZORGTABAR ◽  
MEHDI SALEHI ◽  
MOHAMMADREZA RAHIMIPOUR ◽  
MOHAMMADREZA JAFARPOUR

Titanium dioxide coatings were deposited by utilizing atmospheric plasma-spraying system. The agglomerated P25/20 nano-powder and different spraying parameters (e.g., Argon flow rate and spray distance) were used to determine their influences on the microstructure, crystalline structure, photo-absorption, and photo-catalytic performance of the coatings. The microstructure and phases of as-sprayed TiO 2 coatings were characterized by scanning electron microscope SEM and X-ray diffraction, respectively. Surface characteristics were investigated by Fourier Transform Infrared. Photo-catalytic efficiency of the elaborated samples was also determined in an environmental test chamber set-up and evaluated from the conversion rate of ethanol. The photo-absorption was determined by UV–Vis spectrophotometer. The as-sprayed TiO2 coating was photo-catalytically reactive for the degradation of ethanol. The photo-catalytic activity was influenced by spray conditions. It is found that the photo-catalytic activity is significantly influenced by anatase content, surface area, and surface state. The results showed that the argon flow rate has an influence on the microstructure, anatase content, and photo-catalytic activity of the TiO 2 coatings.


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