scholarly journals Chemo-Bio Catalysis Using Carbon Supports: Application in H2-Driven Cofactor Recycling

2020 ◽  
Author(s):  
Xu Zhao ◽  
Sarah Cleary ◽  
Ceren Zor ◽  
Nicole Grobert ◽  
Holly Reeve ◽  
...  
Keyword(s):  
Catalyst Activity ◽  
Carbon Support ◽  
Carbon Supports ◽  
Reaction Conditions ◽  
Support Materials ◽  
Cofactor Recycling ◽  
Metal Metal ◽  
Hydrogenation Reactions ◽  
Available Carbon ◽  
H2 Oxidation

<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>

scholarly journals Chemo-Bio Catalysis Using Carbon Supports: Application in H2-Driven Cofactor Recycling

2020 ◽  
Author(s):  
Xu Zhao ◽  
Sarah Cleary ◽  
Ceren Zor ◽  
Nicole Grobert ◽  
Holly Reeve ◽  
...  
Keyword(s):  
Catalyst Activity ◽  
Carbon Support ◽  
Carbon Supports ◽  
Reaction Conditions ◽  
Support Materials ◽  
Cofactor Recycling ◽  
Metal Metal ◽  
Hydrogenation Reactions ◽  
Available Carbon ◽  
H2 Oxidation

<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>

scholarly journals Chemo-bio catalysis using carbon supports: application in H2-driven cofactor recycling

2021 ◽  
Author(s):  
Xu Zhao ◽  
Sarah E Cleary ◽  
Ceren Zor ◽  
Nicole Grobert ◽  
Holly A Reeve ◽  
...  
Keyword(s):  
Carbon Supports ◽  
Cofactor Recycling ◽  
Metal Metal ◽  
Available Carbon ◽  
Supported Metal

Heterogeneous biocatalytic hydrogenation is an attractive strategy for clean, enantioselective C=X reduction. This approach relies on enzymes powered by H2-driven NADH recycling. Commercially available carbon-supported metal (metal/C) catalysts are investigated...

scholarly journals Room-Temperature Metathesis of Ethylene with 2-Butene to Propene Over MoOx-Based Catalysts: Mixed Oxides as Perspective Support Materials

2021 ◽  
Author(s):  
Tatiana Otroshchenko ◽  
Qiyang Zhang ◽  
Evgenii V. Kondratenko
Keyword(s):  
Room Temperature ◽  
Mixed Oxides ◽  
Catalyst Activity ◽  
Lattice Defects ◽  
Intrinsic Activity ◽  
Metathesis Reaction ◽  
Acidic Properties ◽  
Reaction Conditions ◽  
Support Materials ◽  
Highly Dispersed

AbstractWe investigated the effect of supports based on ZrO2, TiO2, Al2O3, and SiO2 on the rate of propene formation in the metathesis of ethylene with 2-butene at 50 °C over Mo-containing catalysts possessing highly dispersed MoOx. Large improvements in this rate were achieved when using supports composed of mixed oxides (ZrO2–SiO2, ZrO2–PO4, TiO2–SiO2; Al2O3–SiO2) rather than of individual oxides (ZrO2, TiO2, Al2O3, SiO2). Although previous literature studies dealing with the metathesis reaction over Al2O3- or SiO2-suppported catalysts at higher temperatures suggest the importance of redox or acidic properties of supported MoOx species for catalyst activity, we were not able to establish any general direct correlation in this regard. Contrarily, the rate of propene formation can be significantly enhanced when promoting supports with an oxide promoter. We suggest that the created support lattice defects may facilitate the transformation of MoOx to Mo carbenes under reaction conditions or improve the intrinsic activity of the latter. Graphic Abstract

Carbon Supported Pt+Os Catalysts for Methanol Oxidation

2002 ◽  
Vol 57 (2) ◽  
pp. 193-201 ◽  
Author(s):  
Gülsün Gökağaç ◽  
Brendan J. Kennedy
Keyword(s):  
Methanol Oxidation ◽  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
Carbon Support ◽  
Methanol Oxidation Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Metal Metal ◽  
Metal Support

11% Pt/C, 10% Pt + 1%Os/C, 9% Pt + 2%Os/C, 8% Pt + 3%Os/C, 7% Pt + 4%Os/C, 6% Pt + 5%Os/C and 5%Pt + 6% Os/C catalysts have been prepared for methanol oxidation reaction. Transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction and cyclic voltammetry have been used to understand the nature of the species present in these catalysts. 7% Pt + 4% Os/C was the most active catalyst, while 8% Pt + 3% Os/C was the least active one. It is found that the metal particle size and distribution on the carbon support, the surface composition and the oxidation states of the metal particles, the metal-metal and metal support interactions are important parameters to define the activity of the catalyst.

Study on the Hydrotreating Catalysts Containing Phosphorus of Coal Tar to Clean Fuels

2012 ◽  
Vol 531 ◽  
pp. 263-267 ◽  
Author(s):  
Hong Hua Zhang ◽  
Yi Min Cao ◽  
Muhammad Usman ◽  
Li Jun Li ◽  
Chun Shan Li
Keyword(s):  
Coal Tar ◽  
Liquid Product ◽  
Space Velocity ◽  
Temperature Programming ◽  
Test Results ◽  
Reaction Conditions ◽  
Hydrotreating Catalyst ◽  
Ultrasonic Assisted ◽  
Hydrogenation Reactions ◽  
Catalytic Hydrotreating

The effect of phosphorus catalysts for hydrogenation reactions were studied in this work. Different catalysts supported on γ-Al2O3 containing phosphorus (WNiP/γ-Al2O3, MoNiP/γ-Al2O3, WMoNiP/γ-Al2O3 and WMoCoP/γ-Al2O3) were prepared through ultrasonic-assisted impregnation and temperature-programming methods. The catalytic hydrotreating reaction are under the reaction conditions of PH2=9MPa, Thf=370oC, space velocity=0.5h-1, and H2/oil ratio=1400. Gasoline (≤180oC) and diesel (180–360oC) are separated from the liquid product. The fractions were characterized by Elemental analysis, FTIR, KY3000 S/N and GC-MS analysis. Though analysis of test results, it can be concluded that the WNiP/γ-Al2O3 is the excellent hydrotreating catalyst in this series at this reaction condition.

scholarly journals Thermal Modification Effect on Supported Cu-Based Activated Carbon Catalyst in Hydrogenolysis of Glycerol

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 603 ◽  
Author(s):  
Juan Seguel ◽  
Rafael García ◽  
Ricardo José Chimentão ◽  
José Luis García-Fierro ◽  
I. Tyrone Ghampson ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Hydrogen Adsorption ◽  
Carbon Support ◽  
Catalytic Performance ◽  
Homogeneous Distribution ◽  
Surface Groups ◽  
Carbon Supports ◽  
Surface Areas ◽  
Oxygen Surface

Glycerol hydrogenolysis to 1,2-propanediol (1,2-PDO) was performed over activated carbon supported copper-based catalysts. The catalysts were prepared by impregnation using a pristine carbon support and thermally-treated carbon supports (450, 600, 750, and 1000 °C). The final hydrogen adsorption capacity, porous structure, and total acidity of the catalysts were found to be important descriptors to understand catalytic performance. Oxygen surface groups on the support controlled copper dispersion by modifying acidic and adsorption properties. The amount of oxygen species of thermally modified carbon supports was also found to be a function of its specific surface area. Carbon supports with high specific surface areas contained large amount of oxygen surface species, inducing homogeneous distribution of Cu species on the carbon support during impregnation. The oxygen surface groups likely acted as anchorage centers, whereby the more stable oxygen surface groups after the reduction treatment produced an increase in the interaction of the copper species with the carbon support, and determined catalytic performances.

Microcharacterization of New Platinum Catalysts for Hydrosilylation Reactions

2001 ◽  
Vol 7 (S2) ◽  
pp. 1082-1083
Author(s):  
Wei Chen ◽  
Lawrence F. Allard ◽  
Paul C. Dinh ◽  
Ming-Shin Tzou ◽  
Kevin McIIwrath
Keyword(s):  
Bimetallic Catalysts ◽  
Copper Chloride ◽  
Platinum Catalysts ◽  
Catalyst Particle ◽  
Carbon Support ◽  
Support Materials ◽  
Oxide Support ◽  
Conversion Rates ◽  
Supporting Material ◽  
Acidic Nature

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.

scholarly journals Bleached Wood Supports for Floatable, Recyclable, and Efficient Three Dimensional Photocatalyst

Catalysts ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 115 ◽  
Author(s):  
Yuming He ◽  
Huayang Li ◽  
Xuelian Guo ◽  
Rongbo Zheng
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Degradation ◽  
Three Dimensional ◽  
Carbon Support ◽  
Support Materials ◽  
Lignin Removal ◽  
Photodegradation Efficiency ◽  
Uv Transmittance ◽  
Nanoparticles Suspension ◽  
Black Color

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.

Preparation of Monometallic Catalysts on Carbon Support for Synthesis of Biodiesel Fuel

2019 ◽  
Vol 824 ◽  
pp. 219-224
Author(s):  
Tripob Longprang ◽  
Parncheewa Udomsap ◽  
Nuwong Chollacoop ◽  
Masayoshi Fuji ◽  
Apiluck Eiad-Ua
Keyword(s):  
Hydrothermal Process ◽  
Carbon Support ◽  
Metal Catalyst ◽  
Biodiesel Fuel ◽  
Partial Hydrogenation ◽  
Support Surface ◽  
Impregnation Method ◽  
Hydrothermal Temperature ◽  
Support Materials ◽  
Monometallic Catalysts

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.

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