scholarly journals Microbial Phosphotriesterase: Structure, Function, and Biotechnological Applications

Catalysts ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 671 ◽  
Author(s):  
Wahhida Latip ◽  
Victor Feizal Knight ◽  
Norhana Abdul Halim ◽  
Keat Khim Ong ◽  
Noor Azilah Mohd Kassim ◽  
...  
Keyword(s):  
Nervous System ◽  
Catalytic Activity ◽  
Active Site ◽  
Soil Bacteria ◽  
Environmental Issues ◽  
High Catalytic Activity ◽  
Biotechnological Applications ◽  
Microbial Enzymes ◽  
Toxicity Effects

The role of phosphotriesterase as an enzyme which is able to hydrolyze organophosphate compounds cannot be disputed. Contamination by organophosphate (OP) compounds in the environment is alarming, and even more worrying is the toxicity of this compound, which affects the nervous system. Thus, it is important to find a safer way to detoxify, detect and recuperate from the toxicity effects of this compound. Phosphotriesterases (PTEs) are mostly isolated from soil bacteria and are classified as metalloenzymes or metal-dependent enzymes that contain bimetals at the active site. There are three separate pockets to accommodate the substrate into the active site of each PTE. This enzyme generally shows a high catalytic activity towards phosphotriesters. These microbial enzymes are robust and easy to manipulate. Currently, PTEs are widely studied for the detection, detoxification, and enzyme therapies for OP compound poisoning incidents. The discovery and understanding of PTEs would pave ways for greener approaches in biotechnological applications and to solve environmental issues relating to OP contamination.

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.

Role of microporous Janus silica nanosheets in the assembly of ultra-small Ag nanoparticles with high catalytic activity

2021 ◽  
Vol 50 (1) ◽  
pp. 208-216
Author(s):  
Mengnan Yang ◽  
Zhaoli Yan ◽  
Tiantian Li ◽  
Bing Liu ◽  
Qiangshan Jing ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Ag Nanoparticles ◽  
High Catalytic Activity ◽  
Charged Surface ◽  
Highly Efficient ◽  
Surface Hydroxyls

Negatively charged surface hydroxyls and micropores of Janus silica nanosheets play a particular role in the highly efficient and dispersed assembly of ultra-small Ag nanoparticles with high catalytic activity.

LDH-derived catalysts for complete oxidation of volatile organic compounds

Clay Minerals ◽  
1999 ◽  
Vol 34 (1) ◽  
pp. 67-77 ◽  
Author(s):  
K. Bahranowski ◽  
E. Bielańska ◽  
R. Janik ◽  
T. Machej ◽  
E. M. Serwicka
Keyword(s):  
Catalytic Activity ◽  
Mixed Oxide ◽  
Copper Chromite ◽  
Oxide System ◽  
High Catalytic Activity ◽  
Commercial Catalyst ◽  
Volatile Organic ◽  
Double Hydroxides ◽  
Very High

AbstractThe Cu,Cr-, Zn,Cr- and Cu,Al-layered double hydroxides have been synthesized by the coprecipitation method and characterized by elemental analysis, PXRD, SEM/EDS and BET. The mixed oxide materials obtained upon calcination at 873 K show very high catalytic activity for the combustion of toluene and ethanol. The best sample is derived from the Cu,Cr-LDH precursor with a Cu:Cr ratio of 2, composed of copper oxide and copper chromite. This catalyst gave 50% conversion of toluene and ethanol at temperatures of 45 and 15 K lower, respectively, than the reference commercial catalyst. Catalytic tests with a mechanical mixture of CuO and CuCr2O4 demonstrate that the use of an LDH precursor is essential for optimum results. The importance of the simultaneous presence of both Cu and Cr, the influence of the Cu:Cr ratio on the catalytic activity and the role of the interface boundaries in the CuO-CuCr2O4 mixed oxide system are discussed.

Chitosan Based Nanocomposite Materials as Photocatalyst – A Review

2014 ◽  
Vol 781 ◽  
pp. 79-94 ◽  
Author(s):  
A. Nithya ◽  
Kandasamy Jothivenkatachalam ◽  
S. Prabhu ◽  
K. Jeganathan
Keyword(s):  
Catalytic Activity ◽  
Environmental Remediation ◽  
Low Cost ◽  
Nanocomposite Materials ◽  
Heterogeneous Photocatalysis ◽  
Organic Polymer ◽  
High Catalytic Activity ◽  
Environmental Application ◽  
Industrial Activities

Heterogeneous photocatalysis is a significant technology for environmental application. Moreover, immobilising an appropriate catalyst on the surface of a natural organic polymer presents a number of additional advantages including low-cost, high catalytic activity and extensive potential reuse for the application of pharmaceutical, biomedical and industrial activities. This review mainly focuses on the role of chitosan based material as photocatalyst on the environmental remediation.

scholarly journals Insights into the role of an Fe–N active site in the oxygen reduction reaction on carbon-supported supramolecular catalysts

RSC Advances ◽  
2020 ◽  
Vol 10 (15) ◽  
pp. 8709-8716
Author(s):  
Lin Gu ◽  
Yunyun Dong ◽  
Yan Zhang ◽  
Bo Wang ◽  
Qing Yuan ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Active Site ◽  
Active Sites ◽  
Reduction Reaction ◽  
Alkaline Media ◽  
Supramolecular Catalysts

The PPYTZ–Fe/C catalyst containing Fe–N active sites exhibited high ORR catalytic activity and stability in alkaline media with a four-electron pathway progress.

Sign in / Sign up

Export Citation Format

Share Document