Heterogeneous base catalytic transesterification synthesis of sucrose ester and parallel reaction control

2013 ◽  
Vol 49 (3) ◽  
pp. 854-860 ◽  
Author(s):  
Rongrong Zhao ◽  
Zhidong Chang ◽  
Qiong Jin ◽  
Wenjun Li ◽  
Bin Dong ◽  
...  
Keyword(s):  
Sucrose Ester ◽  
Parallel Reaction ◽  
Heterogeneous Base

Catalytic Resonance Theory: Parallel Reaction Pathway Control

2019 ◽  
Author(s):  
M. Alexander Ardagh ◽  
Manish Shetty ◽  
Anatoliy Kuznetsov ◽  
Qi Zhang ◽  
Phillip Christopher ◽  
...  
Keyword(s):  
Chemical Reactions ◽  
Active Site ◽  
Active Sites ◽  
Reaction Pathway ◽  
Control Strategies ◽  
Oscillation Amplitude ◽  
Catalytic Performance ◽  
Parallel Reaction ◽  
Resonance Theory ◽  
Static Conditions

Catalytic enhancement of chemical reactions via heterogeneous materials occurs through stabilization of transition states at designed active sites, but dramatically greater rate acceleration on that same active site is achieved when the surface intermediates oscillate in binding energy. The applied oscillation amplitude and frequency can accelerate reactions orders of magnitude above the catalytic rates of static systems, provided the active site dynamics are tuned to the natural frequencies of the surface chemistry. In this work, differences in the characteristics of parallel reactions are exploited via selective application of active site dynamics (0 < ΔU < 1.0 eV amplitude, 10<sup>-6</sup> < f < 10<sup>4</sup> Hz frequency) to control the extent of competing reactions occurring on the shared catalytic surface. Simulation of multiple parallel reaction systems with broad range of variation in chemical parameters revealed that parallel chemistries are highly tunable in selectivity between either pure product, even when specific products are not selectively produced under static conditions. Two mechanisms leading to dynamic selectivity control were identified: (i) surface thermodynamic control of one product species under strong binding conditions, or (ii) catalytic resonance of the kinetics of one reaction over the other. These dynamic parallel pathway control strategies applied to a host of chemical conditions indicate significant potential for improving the catalytic performance of many important industrial chemical reactions beyond their existing static performance.

The effect of composition of cobalt-molybdenum catalysts on their surface acidity and isomerisation activity

1980 ◽  
Vol 45 (3) ◽  
pp. 697-702 ◽  
Author(s):  
Vlastimil Vyskočil ◽  
Miroslav Zdražil
Keyword(s):  
Chromatographic Method ◽  
Surface Acidity ◽  
Parallel Reaction ◽  
Molybdenum Catalysts ◽  
The Difference ◽  
Kinetics Of ◽  
Alumina Catalysts

Kinetics of isomerisation of cyclohexene to methylcyclopentene proceeding as parallel reaction to hydrogenation of cyclohexene to cyclohexane on cobalt-molybdenum catalysts of different composition has been measured. The surface acidity of these catalysts was estimated from the difference in the adsorption of toluene and heptane which was measured by chromatographic method. In a series of catalysts containing molybdenum the acidity parallels isomerisation activity. Cobalt on alumina catalysts and alumina itself have greater acidity but exhibit lower isomerisation activity compared to the catalysts containing molybdenum.

Effect of Calcination on the Basic Strength of Surface Modified Nano-Zinc Oxide Characterised by FTIR and Back Titration Methods

2015 ◽  
Vol 1107 ◽  
pp. 326-332
Author(s):  
Abdul Rahim Yacob ◽  
Kamaluddeen Suleiman Kabo
Keyword(s):  
Zinc Oxide ◽  
Metal Oxides ◽  
Base Catalysis ◽  
Nano Zinc Oxide ◽  
Back Titration ◽  
And Performance ◽  
Nano Zinc ◽  
Surface Modified ◽  
Heterogeneous Base ◽  
Basic Strength

The use of metal oxides in heterogeneous base catalysis has gained a large interest due to their application in many chemical and industrial processes and is environmental friendly. Basic metal oxides are commonly used and their structures, morphology and performance can be modified by method of preparation and thermal activation. In this study, surface modified amphoteric zinc oxide was prepared via hydration-dehydration method and characterised by TGA and FTIR. The basic strength at various temperatures is characterised by FTIR and back titration analyses. The results shows that surface modified zinc oxide has the highest basic strength of 1.453mmolg-1at 400°C making it a relatively good and suitable compound for use in heterogeneous basic catalysis. This result is also supported by FTIR spectra which show possible relationship between the Lewis O2-and increasing basic strength.

Heterogeneous base catalysts: Synthesis and application for biodiesel production – A review

2021 ◽  
pp. 125054
Author(s):  
Mani Jayakumar ◽  
Natchimuthu Karmegam ◽  
Marttin Paulraj Gundupalli ◽  
Kaleab Bizuneh Gebeyehu ◽  
Belete Tessema Asfaw ◽  
...  
Keyword(s):  
Biodiesel Production ◽  
Base Catalysts ◽  
Heterogeneous Base

Effects of Addition of a Palmitic Sucrose Ester on Low-Trans-Fat Blends Crystallization in Bulk and in Oil-in-Water Emulsions

2009 ◽  
Vol 4 (3) ◽  
pp. 158-166 ◽  
Author(s):  
Cristián Huck-Iriart ◽  
Roberto J. Candal ◽  
Maria L. Herrera
Keyword(s):  
Sucrose Ester ◽  
Trans Fat ◽  
Oil In Water
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