Synthesis, Characterization and the gas phase catalytic activity of metal doped nanoporous carbon

2002 ◽  
Vol 738 ◽  
Author(s):  
Ponnaiyan Ayyappan ◽  
Henry C. Foley
Keyword(s):  
Catalytic Activity ◽  
Gas Phase ◽  
Nanoporous Carbon ◽  
Acid Base ◽  
Catalytic Activities ◽  
Polyfurfuryl Alcohol ◽  
Evolved Gases ◽  
Acid Base Titration ◽  
Reflectance Ftir ◽  
Metal Doped

ABSTRACTMetal doped nanoporous carbon(NPC) materials, based on polyfurfuryl alcohol and polyethylene glycol were synthesized using new method. The characterization were carried out using acid-base titration, PXRD, TEM, diffused reflectance FTIR, SEM and mass spectrometer. Their gas phase catalytic activities were checked by passing CO and H2 through the catalysts. Carbondioxide and methane were the evolved gases when CO was passed through the catalyst, whereas carbonmonoxide and methane are the resultant gases when H2 was taken up by the catalyst.

scholarly journals Gas-Phase Epoxidation of Propylene to Propylene Oxide on a Supported Catalyst Modified with Various Dopants

Catalysts ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 638 ◽  
Author(s):  
Sugiyama ◽  
Sakuwa ◽  
Ogino ◽  
Sakamoto ◽  
Shimoda ◽  
...  
Keyword(s):  
Gas Phase ◽  
Propylene Oxide ◽  
Active Catalyst ◽  
Supported Catalyst ◽  
Acid Base ◽  
Epoxidation Of Propylene ◽  
Highly Active ◽  
Acidic Catalysts ◽  
Carbonate Species ◽  
Metal Doped

In the present study, the production of propylene oxide (PO) from propylene via gas-phase epoxidation was investigated using various catalysts. Although Ag is known to be a highly active catalyst for the epoxidation of ethylene, it was not active in the present reaction. Both Al and Ti showed high levels of activity, however, which resulted in confusion. The present study was conducted to solve such confusion. Although the employment of MCM-41 modified with Ti and/or Al was reported as an active catalyst for epoxidation, the combination resulted in the formation of PO at a less than 0.1% yield. Since this research revealed that the acidic catalyst seemed favorable for the formation of PO, versions of ZSM-5 that were both undoped and doped with Na, Ti, and Ag were used as catalysts. In these cases, small improvements of 0.67% and 0.57% were achieved in the PO yield on H‒ZSM-5 and Ti‒ZSM-5, respectively. Based on the results of the Ti-dopant and acidic catalysts, Ag metal doped on carbonate species with a smaller surface area was used as a catalyst. As reported, Ag‒Na/CaCO3 showed a greater yield of PO at 1.29%. Furthermore, the use of SrCO3 for CaCO3 resulted in a further improvement in the PO yield to 2.17%. An experiment using CO2 and NH3 pulse together with SEM and TEM examinations for Ag‒Na/CaCO3 revealed that the greatest activity was the result of the greater particle size of metallic Ag rather than the acid‒base properties of the catalysts.

Catalytic Oxidation of Furfural to Succinic Acid in the Presence of Sulfonic Resins

2020 ◽  
Vol 856 ◽  
pp. 182-189
Author(s):  
Wipawan Kingkaew ◽  
Thanis Kaewwiset ◽  
Uthen Thubsuang ◽  
Сhairat Siripattana ◽  
Kamchai Nuithitikul
Keyword(s):  
Succinic Acid ◽  
Oxidation Reaction ◽  
Heterogeneous Catalysts ◽  
Batch Reactor ◽  
Acid Base ◽  
Amberlyst 15 ◽  
Catalytic Activities ◽  
Acid Base Titration ◽  
Sulfonic Resins ◽  
Adsorption Desorption

This research investigates the application of three sulfonic resins (Amberlyst-15, Dowex-G26 and Dowex Monosphere-650C) as acid heterogeneous catalysts for oxidation reaction of furfural with hydrogen peroxide solution. The reaction was carried out in a batch reactor with varied reaction time (4-24 h) and temperature (70-90 °C). The sulfonic resins were characterized as to their structure and chemical composition by N2 adsorption-desorption isotherm, Fourier transformed-infrared (FTIR) spectroscopy, acid-base titration, and scanning electron microscopy (SEM). The results showed that all three resins gave similar catalytic activities. The highest yield of succinic acid was 75.7 % in the presence of Dowex-G26 catalyst at 80 °C and 4 h.

scholarly journals Effect of Mo-Doped Mesoporous Al-SSP Catalysts for the Catalytic Dehydration of Ethanol to Ethylene

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Titinan Chanchuey ◽  
Chaowat Autthanit ◽  
Bunjerd Jongsomjit
Keyword(s):  
Catalytic Activity ◽  
Gas Phase ◽  
Sol Gel ◽  
Acid Sites ◽  
Weak Acid ◽  
Acid Property ◽  
Dehydration Reaction ◽  
Ethanol Dehydration ◽  
High Concentration ◽  
Catalytic Activities

The catalytic dehydration of ethanol to ethylene over the mesoporous Al-SSP and Mo-doped Al-SSP catalysts was investigated. The Al-SSP catalyst was first synthesized by the modified sol-gel method and then doped with Mo by impregnation to obtain 1% Mo/Al-SSP and 5% Mo/Al-SSP catalysts (1 and 5 wt% of Mo). The final catalysts were characterized using various techniques such as XRD, N2physisorption, SEM/EDX, TEM, and NH3-TPD. The catalytic activity for all catalysts in gas-phase ethanol dehydration reaction was determined at temperature range of 200°C to 400°C. It was found that the most crucial factor influencing the catalytic activities appears to be the acidity. The acid property of catalysts depended on the amount of Mo loading. Increased Mo loading in Al-SSP resulted in increased weak acid sites, which enhanced the catalytic activity. Besides acidity, the high concentration of Al at surface of catalyst is also essential to obtain high activity. Based on the results, the most suitable catalyst in this study is 1% Mo/Al-SSP catalyst, which can produce ethylene yield of ca. 90% at 300°C with slight amounts of diethyl ether (DEE) and acetaldehyde.

scholarly journals Effect of Nb doping in WO3/ZrO2 catalysts on gas phase dehydration of glycerol to form acrolein

RSC Advances ◽  
2017 ◽  
Vol 7 (66) ◽  
pp. 41880-41888 ◽  
Author(s):  
Ku-Hsiang Sung ◽  
Soofin Cheng
Keyword(s):  
Catalytic Activity ◽  
Gas Phase ◽  
Tungstated Zirconia ◽  
Acid Base ◽  
Niobium Doping ◽  
Nb Doping ◽  
Base Properties

Gas-phase dehydration of glycerol to produce acrolein was investigated over tungstated zirconia catalysts with and without niobium doping, in order to correlate the catalytic activity and life-stability with the acid/base properties of the catalysts.

Reusable and Efficient PS-Supported Acidic Ionic Liquid Catalyst for Mononitration of Toluene

2012 ◽  
Vol 581-582 ◽  
pp. 252-256 ◽  
Author(s):  
Li Xia Li ◽  
Qi Long Ling ◽  
Xiao Dong Xing ◽  
Ye Zhang ◽  
Zu Liang Liu
Keyword(s):  
Ionic Liquid ◽  
Catalytic Activity ◽  
Nitric Acid ◽  
Acid Base ◽  
Acidic Ionic Liquid ◽  
Acid Base Titration ◽  
Ft Ir

A polystyrene-supported 1-(propyl-3-sulfonate)-3-methy-imidazolium hydrosulfate acidic ionic liquid (PS-[SO3H-PMIM][HSO4]) catalyst was prepared by grafting and characterized by FT-IR, SEM/TEM, elements analysis, TG/DSC and acid base titration. It exhibited higher catalytic activity and improved para-selectivity than its homogenous counterpart for the nitration of toluene with 68% nitric acid. The catalytic activity of this catalyst decreased slightly after fifth runs in the synthesis of nitrotoluene.

Henderson Hasselbalch Relationship and Weak Acid Titration

2019 ◽  
Author(s):  
Marc Blétry
Keyword(s):  
Theoretical Framework ◽  
Weak Acid ◽  
Acid Base ◽  
Sensitive Technique ◽  
Chemistry Students ◽  
Advanced Students ◽  
Acid Titration ◽  
Acid Base Titration ◽  
Analytical Expressions

Henderson-Hasselbalch relation is generally the simplified theoretical framework used to introduce students to acid-base titration. However, it is not always valid and its limitations should be made clear to chemistry students. The appropriate parameter to evaluate its validity is K a /C 0 , in connection with Ostwald dilution law. For more advanced students, it is possible to deduce analytical expressions that always fit accurately acid-base titrations and allow an evaluation of Henderson Hasselbalch relation. Gran plot appears as a particularly sensitive technique to the breakdown of Henderson Hasselbalch relation.

The effect of partial exchange of sulphonated macroporous styrene-divinylbenzene copolymers for different ions on their catalytic activity

1981 ◽  
Vol 46 (10) ◽  
pp. 2354-2363 ◽  
Author(s):  
Svatomír Kmošták ◽  
Karel Setínek
Keyword(s):  
Catalytic Activity ◽  
Transition Metal ◽  
Metal Ions ◽  
Gas Phase ◽  
Transition Metal Ions ◽  
Exchange Capacity ◽  
Total Exchange Capacity ◽  
Styrene Divinylbenzene ◽  
Na Ions ◽  
Type Of Transition

The catalytic activity of sulphonated macroporous styrene-divinylbenzene copolymers, the exchange capacity of which was neutralized from 30, 50 and 80% by Fe(III) ions and from 30% by Na ions and that of Wofatit Y-37 ion exchanger neutralized from 10% of its total exchange capacity by several transition metal ions and by sodium has been studied in isomerisation of cyclohexene and dehydration of 1-propanol in the gas phase at 130 °C. It was demonstrated that in both reactions transition metal ions exhibit additional effect to the expected neutralization of the polymer acid groups. In the case of cyclohexene isomerization, this effect depends on the degree of crosslinking of polymer mass of the catalyst. Such dependence has not been, however, observed in dehydration of 1-propanol. The type of transition metal ions did not exhibit any significant effect on the catalytic activity of the polymer catalysts studied.

scholarly journals Study of deactivation in mesocellular foam carbon (MCF-C) catalyst used in gas-phase dehydrogenation of ethanol

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yoottapong Klinthongchai ◽  
Seeroong Prichanont ◽  
Piyasan Praserthdam ◽  
Bunjerd Jongsomjit
Keyword(s):  
Catalytic Activity ◽  
Pore Size ◽  
Gas Phase ◽  
Surface Area ◽  
Active Sites ◽  
Operating Temperature ◽  
Coke Formation ◽  
Ethanol Conversion ◽  
Deactivation Of Catalyst ◽  
Dehydrogenation Of Ethanol

AbstractMesocellular foam carbon (MCF-C) is one the captivating materials for using in gas phase dehydrogenation of ethanol. Extraordinary, enlarge pore size, high surface area, high acidity, and spherical shape with interconnected pore for high diffusion. In contrary, the occurrence of the coke is a majority causes for inhibiting the active sites on catalyst surface. Thus, this study aims to investigate the occurrence of the coke to optimize the higher catalytic activity, and also to avoid the coke formation. The MCF-C was synthesized and investigated using various techniques. MCF-C was spent in gas-phase dehydrogenation of ethanol under mild conditions. The deactivation of catalyst was investigated toward different conditions. Effects of reaction condition including different reaction temperatures of 300, 350, and 400 °C on the deactivation behaviors were determined. The results indicated that the operating temperature at 400 °C significantly retained the lowest change of ethanol conversion, which favored in the higher temperature. After running reaction, the physical properties as pore size, surface area, and pore volume of spent catalysts were decreased owing to the coke formation, which possibly blocked the pore that directly affected to the difficult diffusion of reactant and caused to be lower in catalytic activity. Furthermore, a slight decrease in either acidity or basicity was observed owing to consumption of reactant at surface of catalyst or chemical change on surface caused by coke formation. Therefore, it can remarkably choose the suitable operating temperature to avoid deactivation of catalyst, and then optimize the ethanol conversion or yield of acetaldehyde.

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