scholarly journals Quantitative Impact of Fluid vs. Solid Interfaces on the Catalytic Performance of Pickering Emulsions

2020 ◽  
Author(s):  
Sebastian Stock ◽  
Annika Schlander ◽  
Maresa Kempin ◽  
Ramsia Geisler ◽  
Dmitrij Stehl ◽  
...  
Keyword(s):  
Catalytic Performance ◽  
Pickering Emulsions ◽  
Biphasic Catalysis ◽  
Quantitative Impact

Pickering emulsions (PEs) i. e. particle stabilized emulsions, are used as reaction environment in biphasic catalysis for the hydroformylation of 1-dodecene into tridecanal using the catalyst rhodium (Rh)-sulfoxantphos (SX). The...

Facile immobilization of lipase based on Pickering emulsion via a synergistic stabilization by palygorskite–enzyme

Clay Minerals ◽  
2019 ◽  
Vol 54 (3) ◽  
pp. 293-298
Author(s):  
Dong Li ◽  
Min Shen ◽  
Guofan Sun ◽  
Huiran Jin ◽  
Peng Cai ◽  
...  
Keyword(s):  
Optical Microscopy ◽  
Immobilized Lipase ◽  
Aqueous Dispersion ◽  
Pickering Emulsion ◽  
Catalytic Performance ◽  
Pickering Emulsions ◽  
Emulsion Droplets ◽  
Level Of Activity ◽  
High Level

AbstractA Pickering emulsion was prepared via synergistic stabilization of a lipase and palygorskite particles. The optimum conditions for the stabilization of the Pickering emulsion, such as the concentrations of the palygorskite particles and lipase, were explored. The morphology of emulsion droplets was examined using digital optical microscopy and polarizing optical microscopy. The palygorskite–lipase co-stabilized Pickering emulsions were investigated by determination of the adsorption rate, pH and zeta potential of the aqueous dispersion, as well as by determining the contact angle values of the lipase solution on a palygorskite disc that was immersed in toluene. The catalytic performance of the immobilized lipase in the Pickering emulsion was studied via the investigation of its thermal stability, storage stability and reusability. The immobilized lipase showed greater stability than the free lipase. The lipase immobilized by Pickering emulsion retained a high level of activity even after seven periods of recycling.

scholarly journals Interface-Active Metal Organic Frameworks for Knoevenagel Condensations in Water

Catalysts ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 315 ◽  
Author(s):  
Yanmei Zhang ◽  
Xiang Zhang ◽  
Rixia Bai ◽  
Xiyan Hou ◽  
Jun Li
Keyword(s):  
Knoevenagel Condensation ◽  
Active Catalyst ◽  
Metal Organic Framework ◽  
Catalytic Performance ◽  
Pickering Emulsions ◽  
Reaction Conditions ◽  
Solid Catalysts ◽  
Active Metal ◽  
Metal Organic ◽  
Oil Water

It is desirable but challenging to locate solid catalysts at the oil-water interface to stabilize “Pickering emulsions”, which is one of the promising ways to develop efficient green chemical processes. Herein, water-stable metal organic framework ZIF-8 without any chemical modification was demonstrated to be an interface-active catalyst for Knoevenagel condensation in a biphasic system. Pickering emulsion formed under the reaction conditions due to its amphiphilic property, which was beneficial to the mass transfer and led to high catalytic performance. Moreover, it can be repeatedly applied for Knoevenagel condensation for at least six successive cycles without losing its catalytic activity and framework integrity.

The design and catalytic performance of molybdenum active sites on an MCM-41 framework for the aerobic oxidation of 5-hydroxymethylfurfural to 2,5-diformylfuran

2019 ◽  
Vol 9 (3) ◽  
pp. 811-821 ◽  
Author(s):  
Zhao-Meng Wang ◽  
Li-Juan Liu ◽  
Bo Xiang ◽  
Yue Wang ◽  
Ya-Jing Lyu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Active Sites ◽  
Aerobic Oxidation ◽  
Catalytic Performance ◽  
Mcm 41

The catalytic activity decreases as –(SiO)3Mo(OH)(O) > –(SiO)2Mo(O)2 > –(O)4–MoO.

Optimizing electron density of nickel sulfide electrocatalysts through sulfur vacancy engineering for alkaline hydrogen evolution

2020 ◽  
Vol 8 (35) ◽  
pp. 18207-18214
Author(s):  
Dongbo Jia ◽  
Lili Han ◽  
Ying Li ◽  
Wenjun He ◽  
Caichi Liu ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Electron Density ◽  
Rational Design ◽  
Nickel Sulfide ◽  
Catalytic Performance ◽  
Sulfide Catalysts ◽  
Sulfur Vacancy

A novel, rational design for porous S-vacancy nickel sulfide catalysts with remarkable catalytic performance for alkaline HER.

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.

Fabrication and Excellent Catalytic Performance of Three-dimensional Ordered Mesoporous Molybdenum Oxides

2014 ◽  
Vol 29 (2) ◽  
pp. 124-130 ◽  
Author(s):  
Yu-Cheng DU ◽  
Guang-Wei ZHENG ◽  
Qi MENG ◽  
Li-Ping WANG ◽  
Hai-Guang FAN ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Catalytic Performance ◽  
Molybdenum Oxides ◽  
Ordered Mesoporous ◽  
Excellent Catalytic Performance

Preparation of CeO2-ZrO2-Al2O3 and Catalytic Performance of Palladium-Based Three-Way Catalyst

2010 ◽  
Vol 31 (4) ◽  
pp. 429-434
Author(s):  
Ming ZHAO ◽  
Hairong WANG ◽  
Shanhu CHEN ◽  
Yanling YAO ◽  
Maochu GONG ◽  
...  
Keyword(s):  
Catalytic Performance ◽  
Three Way Catalyst

Effect of Supports on Catalytic Performance of Nickel-Based Catalyst for Methanation

2014 ◽  
Vol 32 (8) ◽  
pp. 1400-1404
Author(s):  
Xia LI ◽  
Xiazhen YANG ◽  
Haodong TANG ◽  
Huazhang LIU
Keyword(s):  
Catalytic Performance

Preparation of Cu-Mn/Zr-Ce-SBA-15 Catalyst with Short Mesochannels and Its Catalytic Performance for Toluene Combustion

2014 ◽  
Vol 32 (6) ◽  
pp. 1069-1075
Author(s):  
Jinfang YUAN ◽  
Jiansheng LI ◽  
Fang WANG ◽  
Xiuyun SUN ◽  
Jinyou SHEN ◽  
...  
Keyword(s):  
Catalytic Performance
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