Electrochemical Study of Surface-Functionalized Carbon Support Materials

2001 ◽  
Vol 7 (S2) ◽  
pp. 1082-1083
Author(s):  
Wei Chen ◽  
Lawrence F. Allard ◽  
Paul C. Dinh ◽  
Ming-Shin Tzou ◽  
Kevin McIIwrath

Organofunctional silanes are the key intermediates for production of silicon polymeric chemicals. Traditionally, platinum catalysts on carbon support materials have been used for these hydrosilylation reactions. The efficiency of the current commercial Pt/C catalyst is not very satisfactory, so a catalyst of platinum on aluminum oxide support was developed to accelerate the reactions. The Pt/Al2O3catalyst greatly increases both reaction and conversion rates. However, the acidic nature of the supporting material is sometimes undesirable. Recently, a new class of platinum-copper bimetallic catalysts has been developed at Dow Corning, using co-deposition techniques with platinum chloride and copper chloride precursors. The bimetallic catalysts have also demonstrated significantly improved on hydrosilylation reaction efficiency and rates. The activity, selectivity, and stability of the catalysts are related to their structural properties, including catalyst particle size, size distribution, and particle composition. The knowledge of catalyst structures are, therefore, very important for understanding the performance of the catalysts and for optimizing production processes.


Catalysts ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 115 ◽  
Author(s):  
Yuming He ◽  
Huayang Li ◽  
Xuelian Guo ◽  
Rongbo Zheng

To suppress the agglomeration of a photocatalyst, facilitate its recovery, and avoid photolysis of dyes, various support materials such as ceramic, carbon, and polymer have been investigated. However, these support materials pose the following additional challenges: ceramic supports will settle down at the bottom of their container due to their high density, while the carbon support will absorb the UV-vis light for its black color. Herein, we propose a floatable, UV transmitting, mesoporous bleached wood with most lignin removal to support P25 nanoparticles (BP-wood) that can effectively, recyclable, three dimensional (3D) photocatalytic degrade dyes such as methylene blue (MB) under ambient sunlight. The BP-wood has the following advantages: (1) The delignification makes the BP-wood more porous to not only quickly transport MB solutions upstream to the top surface, but is also decorated with P25 nanoparticles on the cell wall to form a 3D photocatalyst. (2) The delignification endows the BP-wood with good UV transmittance to undergo 3D photocatalytic degradation under sunlight. (3) It can float on the surface of the MB solution to capture more sunlight to enhance the photodegradation efficiency by suppressing the photolysis of MB. (4) It has comparable or even better photocatalytic degradation of 40 mg/L and 60 mg/L MB than that of P25 nanoparticles suspension. (5) It is green, recyclable, and scalable.


2019 ◽  
Vol 824 ◽  
pp. 219-224
Author(s):  
Tripob Longprang ◽  
Parncheewa Udomsap ◽  
Nuwong Chollacoop ◽  
Masayoshi Fuji ◽  
Apiluck Eiad-Ua

Monometallic catalysts have been prepared on nano-porous carbon support materials by way of hydrothermal carbonization of Cattail (genus Typha) leaves. The catalysts are for synthesis of biodiesel fuel. This research studied the effect of hydrothermal temperature (at 160-200 °C), reaction time (4-24 h) and the presence of KOH on the activated porosity of a carbon support. Then the type of loaded metal catalyst (Mn, Fe, Co, Ni, Cu and Pb), placed on the carbon support by an impregnation method, was investigated. This led to partial hydrogenation catalytic activity forming biodiesel. The carbonization temperature was studied in the range 500-900 °C for 2 hours. The samples were characterized by scanning electron microscopy, nitrogen sorption, fourier transform infrared spectroscopy and X-ray diffraction. The results indicated that the hydrothermal process at 200 °C for 12 hours exhibited the highest surface area, porosity and pore volume. This led to an appropriate distribution of metal on the carbon support surface.


2020 ◽  
Vol 10 (14) ◽  
pp. 4794-4808
Author(s):  
Monika Bosilj ◽  
Lina Rustam ◽  
Ralf Thomann ◽  
Julia Melke ◽  
Anna Fischer ◽  
...  

Influencing stability and performance through directing nitrogen-doping in carbon support materials.


2020 ◽  
Author(s):  
Xu Zhao ◽  
Sarah Cleary ◽  
Ceren Zor ◽  
Nicole Grobert ◽  
Holly Reeve ◽  
...  

<div>Commercially available carbon-supported metal (metal/C) catalysts are investigated here for direct H2-driven NAD+ reduction. Selected metal/C catalysts are then</div><div>used for H2 oxidation with electrons transferred via the conductive carbon support material to an adsorbed enzyme for NAD+ reduction. These chemo-bio catalysts show improved activity and selectivity for generating bioactive NADH under ambient reaction conditions compared</div><div>to metal/C catalysts. The metal/C catalysts and carbon support materials (all activated carbon or carbon black) are characterised to probe which properties potentially influence catalyst activity. The optimised chemo-bio catalysts are then used to supply NADH to an alcohol dehydrogenase for enantioselective (>99% ee) ketone reductions, leading to high cofactor turnover numbers and Pd and NAD+ reductase activities of 441 h-1 and 2,347 h-1,</div><div>respectively. This method demonstrates a new way of combining chemo- and biocatalysis on carbon supports, highlighted here for selective hydrogenation reactions.</div>


2004 ◽  
Vol 835 ◽  
Author(s):  
Kazunari Sasaki ◽  
Kenji Shinya ◽  
Shuhei Tanaka ◽  
Yuudai Kawazoe ◽  
Takashi Kuroki ◽  
...  

ABSTRACTNanostructured Platinum-based electrode catalysts were prepared via in-situ colloidal impregnation for polymer electrolyte fuel cells. Crystallite size, grain size, and distribution of Pt nanoparticles on carbon support materials were characterized by XRD, TEM, high-resolution FESEM, and STEM. Effective surface area and kinetically-controlled current density of Pt electrode catalysts were analyzed by cyclic and hydrodynamic voltammetry using rotating disk electrodes. PEFCs with these electrode catalysts were also prepared and their I-V characteristics were examined at 80°C.We have succeeded to develop Pt electrode catalysts with a diameter of a few nm, supported on carbon nanofibers with different structures (including herringbone-type fibers, platelet-type fibers, and highly-conductive vapor-grown fibers), carbon nanotubes, as well as carbon black. The dependencies of nanostructure and electrochemical properties on crystallographic structure of carbon support materials and preparation conditions of electrode catalysts are analyzed and discussed. Nanostructural design of PEFC electrode catalyst layers using carbon nanofibers as catalyst supports and electrode fillers is also discussed.


2020 ◽  
Author(s):  
Xu Zhao ◽  
Sarah Cleary ◽  
Ceren Zor ◽  
Nicole Grobert ◽  
Holly Reeve ◽  
...  

<div>Commercially available carbon-supported metal (metal/C) catalysts are investigated here for direct H2-driven NAD+ reduction. Selected metal/C catalysts are then</div><div>used for H2 oxidation with electrons transferred via the conductive carbon support material to an adsorbed enzyme for NAD+ reduction. These chemo-bio catalysts show improved activity and selectivity for generating bioactive NADH under ambient reaction conditions compared</div><div>to metal/C catalysts. The metal/C catalysts and carbon support materials (all activated carbon or carbon black) are characterised to probe which properties potentially influence catalyst activity. The optimised chemo-bio catalysts are then used to supply NADH to an alcohol dehydrogenase for enantioselective (>99% ee) ketone reductions, leading to high cofactor turnover numbers and Pd and NAD+ reductase activities of 441 h-1 and 2,347 h-1,</div><div>respectively. This method demonstrates a new way of combining chemo- and biocatalysis on carbon supports, highlighted here for selective hydrogenation reactions.</div>


2010 ◽  
Vol 114 (32) ◽  
pp. 13739-13745 ◽  
Author(s):  
Tetsuya Mashio ◽  
Kourosh Malek ◽  
Michael Eikerling ◽  
Atsushi Ohma ◽  
Hiroyuki Kanesaka ◽  
...  

2018 ◽  
Vol 43 (16) ◽  
pp. 7823-7854 ◽  
Author(s):  
Shuaiba Samad ◽  
Kee Shyuan Loh ◽  
Wai Yin Wong ◽  
Tian Khoon Lee ◽  
Jaka Sunarso ◽  
...  

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