The catalytic activity of space versus terrestrial synthesized zeolite Beta catalysts in the Meerwein Ponndorf Verley Reactions: Support for PFAL as the Lewis active site for cis-alcohol selectivity

2007 ◽  
Vol 19 (2) ◽  
pp. 5-11 ◽  
Author(s):  
Burcu Akata ◽  
Trevor L. Goodrich ◽  
Katherine S. Ziemer ◽  
Albert Sacco
Keyword(s):  
Catalytic Activity ◽  
Active Site ◽  
Space Versus ◽  
Zeolite Beta

scholarly journals Flower-Shaped C-Dots/Co3O4{111} Constructed with Dual-Reaction Centers for Enhancement of Fenton-Like Reaction Activity and Peroxymonosulfate Conversion to Sulfate Radical

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 135
Author(s):  
Zhibin Wen ◽  
Qianqian Zhu ◽  
Jiali Zhou ◽  
Shudi Zhao ◽  
Jinnan Wang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Active Site ◽  
High Surface ◽  
High Surface Area ◽  
Reaction Centers ◽  
Organic Radicals ◽  
The Other ◽  
High Catalytic Activity ◽  
High Adsorption ◽  
High Turnover

Novel flower-shaped C-dots/Co3O4{111} with dual-reaction centers were constructed to improve the Fenton-like reaction activity and peroxymonosulfate (PMS) conversion to sulfate radicals. Due to the exposure of a high surface area and Co3O4{111} facets, flower-shaped C-dots/Co3O4{111} could provide more Co(II) for PMS activation than traditional spherical Co3O4{110}. Meanwhile, PMS was preferred for adsorption on Co3O4{111} facets because of a high adsorption energy and thereby facilitated the electron transfer from Co(II) to PMS. More importantly, the Co–O–C linkage between C-dots and Co3O4{111} induced the formation of the dual-reaction center, which promoted the production of reactive organic radicals (R•). PMS could be directly reduced to SO4−• by R• over C-dots. On the other hand, electron transferred from R• to Co via Co–O–C linkage could accelerate the redox of Co(II)/(III), avoiding the invalid decomposition of PMS. Thus, C-dots doped on Co3O4{111} improved the PMS conversion rate to SO4−• over the single active site, resulting in high turnover numbers (TONs). In addition, TPR analysis indicated that the optimal content of C-dots doped on Co3O4{111} is 2.5%. More than 99% of antibiotics and dyes were degraded over C-dots/Co3O4{111} within 10 min. Even after six cycles, C-dots/Co3O4{111} still remained a high catalytic activity.

Origin of the optimum in catalytic activity of zeolite beta

1998 ◽  
Vol 94 (4) ◽  
pp. 617-621 ◽  
Author(s):  
Fre´de´ric Vaudry ◽  
Francesco Di Renzo ◽  
Francois Fajula ◽  
Philippe Schulz
Keyword(s):  
Catalytic Activity ◽  
Zeolite Beta

Dehydration of n-Butanol on Phosphate-Modified Carbon Nanotubes: Active Site and Intrinsic Catalytic Activity

2021 ◽  
Author(s):  
Fan Li ◽  
Xueya Dai ◽  
Xingyu Lu ◽  
Chao Wang ◽  
Wei Qi
Keyword(s):  
Carbon Nanotubes ◽  
Catalytic Activity ◽  
Active Site ◽  
Efficient Utilization ◽  
Reaction Route ◽  
Modified Carbon Nanotubes

Dehydration of n-butanol (nB) to corresponding olefins (butene) is an important reaction route to realize the efficient utilization of bulk bio-alcohols. In this work, a novel phosphate modified oxidized multi-walled...

scholarly journals A possible connection between phosphate tungsten bronzes properties and Briggs-Rauscher oscillatory reaction response

2021 ◽  
Vol 53 (2) ◽  
pp. 223-235
Author(s):  
Tijana Maksimovic ◽  
Jelena Maksimovic ◽  
Pavle Tancic ◽  
Nebojsa Potkonjak ◽  
Zoran Nedic ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Calcium Phosphate ◽  
Active Site ◽  
Unit Cell Volume ◽  
Tungsten Bronze ◽  
Reaction Dynamics ◽  
Unit Cell ◽  
Oscillatory Reaction ◽  
Innovative Method ◽  
Cell Volumes

The calcium phosphate tungsten bronze (Ca-PWB) has been synthesized and characterized (TGA, DSC, XRPD, FTIR, SEM). The influence of solid insoluble materials Ca- PWB, as well as lithium doped (Li-PWB) and cation free phosphate tungsten (PWB) bronzes on the oscillatory Briggs-Rauscher (BR) reaction dynamics, is compared. The results show that doping with Li and Ca reduces sensitivity of the BR reaction towards bronzes addition. These findings suggest the usage of the BR reaction as an innovative method for testing of different properties of bronze material. The behavior of PWB in the BR reaction is significantly changed with divalent cation (Ca2+) doping. The reasons for the different bronzes behavior were found in their calculated unit cell volumes. Namely, the compressed Ca-PWB unit cell volume indicates the difficult availability of the active site for heterogeneous catalysis. Hence, the linear correlation (slope) of the BR oscillogram?s length (?osc) vs. mass of bronze in BR reaction might be considered as a new parameter for the evaluation of the bronzes catalytic activity.

scholarly journals Understanding the Catalytic Activity of Microporous and Mesoporous Zeolites in Cracking by Experiments and Simulations

Catalysts ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1114
Author(s):  
Shih-Cheng Li ◽  
Yen-Chun Lin ◽  
Yi-Pei Li
Keyword(s):  
Catalytic Activity ◽  
Active Site ◽  
Petrochemical Industry ◽  
Molecular Level ◽  
Shape Selectivity ◽  
Zeolite Catalysts ◽  
Hydrocarbon Cracking ◽  
Mesoporous Zeolites ◽  
Secondary Reactions ◽  
Pros And Cons

Porous zeolite catalysts have been widely used in the industry for the conversion of fuel-range molecules for decades. They have the advantages of higher surface area, better hydrothermal stability, and superior shape selectivity, which make them ideal catalysts for hydrocarbon cracking in the petrochemical industry. However, the catalytic activity and selectivity of zeolites for hydrocarbon cracking are significantly affected by the zeolite topology and composition. The aim of this review is to survey recent investigations on hydrocarbon cracking and secondary reactions in micro- and mesoporous zeolites, with the emphasis on the studies of the effects of different porous environments and active site structures on alkane adsorption and activation at the molecular level. The pros and cons of different computational methods used for zeolite simulations are also discussed in this review.

Active site engineering by surface sulfurization for a highly efficient oxygen evolution reaction: a case study of Co3O4 electrocatalysts

2018 ◽  
Vol 6 (45) ◽  
pp. 22497-22502 ◽  
Author(s):  
Ying Pan ◽  
Hangjuan Ren ◽  
Haiwei Du ◽  
Fuyang Cao ◽  
Yifeng Jiang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Oxygen Evolution ◽  
Active Site ◽  
Oxygen Evolution Reaction ◽  
Highly Efficient

Enhanced catalytic activity of Co3O4@CoSx through surface sulfurization.

The effect of ionic liquid on the structure of active site pocket and catalytic activity of a β-glucosidase from Halothermothrix orenii

2020 ◽  
Vol 306 ◽  
pp. 112879 ◽  
Author(s):  
Sukanya Konar ◽  
Sushant K. Sinha ◽  
Supratim Datta ◽  
Pradip Kr. Ghorai
Keyword(s):  
Ionic Liquid ◽  
Catalytic Activity ◽  
Active Site ◽  
Active Site Pocket

scholarly journals 3-D Structure of Serum Paraoxonase 1 Sheds Light on Its Activity, Stability, Solubility and Crystallizability

2007 ◽  
Vol 58 (3) ◽  
pp. 347-353 ◽  
Author(s):  
Michal Harel ◽  
Boris Brumshtein ◽  
Ran Meged ◽  
Hay Dvir ◽  
Raimond Ravelli ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Catalytic Activity ◽  
High Density Lipoprotein ◽  
Active Site ◽  
Density Lipoprotein ◽  
Paraoxonase 1 ◽  
Hydrolytic Activities ◽  
Wide Range ◽  
The Stability ◽  
Serum Paraoxonase

3-D Structure of Serum Paraoxonase 1 Sheds Light on Its Activity, Stability, Solubility and CrystallizabilitySerum paraoxonases (PONs) exhibit a wide range of physiologically important hydrolytic activities, including drug metabolism and detoxification of nerve gases. PON1 and PON3 reside on high-density lipoprotein (HDL) (the "good cholesterol"), and are involved in the alleviation of atherosclerosis. Members of the PON family have been identified not only in mammals and other vertebrates, but also in invertebrates. We earlier described the first crystal structure of a PON family member, a directly-evolved variant of PON1, at 2.2 Å resolution. PON1 is a 6-bladed beta-propeller with a unique active-site lid which is also involved in binding to HDL. The 3-D structure, taken together with directed evolution studies, permitted analysis of mutations which enhanced the stability, solubility and crystallizability of this PON1 variant. The structure permits a detailed description of PON1's active site and suggests possible mechanisms for its catalytic activity on certain substrates.

scholarly journals Shuffling Active Site Substate Populations Affects Catalytic Activity: The Case of Glucose Oxidase

ACS Catalysis ◽  
2017 ◽  
Vol 7 (9) ◽  
pp. 6188-6197 ◽  
Author(s):  
Dušan Petrović ◽  
David Frank ◽  
Shina Caroline Lynn Kamerlin ◽  
Kurt Hoffmann ◽  
Birgit Strodel
Keyword(s):  
Catalytic Activity ◽  
Glucose Oxidase ◽  
Active Site
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