scholarly journals Insights into the structure–property–activity relationship in molybdenum-doped octahedral molecular sieve manganese oxides for catalytic oxidation

2018 ◽  
Vol 8 (24) ◽  
pp. 6493-6502 ◽  
Author(s):  
Homer C. Genuino ◽  
Diego Valencia ◽  
Steven L. Suib

Experimental and computational studies on the properties of Mo-substituted octahedral molecular sieve Mn oxides provide insights into their excellent catalytic activities and stability for CO oxidation.

RSC Advances ◽  
2018 ◽  
Vol 8 (21) ◽  
pp. 11289-11295 ◽  
Author(s):  
Dong Duan ◽  
Chunxi Hao ◽  
Wenyu Shi ◽  
Haiyang Wang ◽  
Zhanbo Sun

A series of Co3O4 catalysts modified by Sm were prepared by a combined dealloying and calcination approach, and the catalytic activities were evaluated using CO catalytic oxidation.


2019 ◽  
Vol 276 ◽  
pp. 06005 ◽  
Author(s):  
Amir Awaluddin ◽  
Riska Anggraini ◽  
Siti Saidah Siregar ◽  
Muhdarina ◽  
Prasetya

The Fe-doped octahedral molecular sieve manganese oxides have been successfully synthesized by one-pot synthesis of the reaction between KMnO4 and glucose using sol-gel methods. The oxide products are then characterized by various techniques such as X-ray diffraction, scanning electron microscopy, atomic absorption spectroscopy and average oxidation state (AOS) of manganese in manganese oxides. The as-synthesized manganese oxide and Fe-doped manganese oxides are used as catalysts for the degradation of methylene blue dye using hydrogen peroxide as oxidants. The results indicated that the Fe-doped manganese oxide catalyst displayed much enhanced catalytic activities compared to undoped manganese oxide for methylene blue degradation. The differences in catalytic activities have been correlated with the difference in surface properties and crystallinity.


ChemCatChem ◽  
2013 ◽  
Vol 5 (8) ◽  
pp. 2306-2317 ◽  
Author(s):  
Homer C. Genuino ◽  
Yongtao Meng ◽  
Dayton T. Horvath ◽  
Chung-Hao Kuo ◽  
Mohammad S. Seraji ◽  
...  

2020 ◽  
Vol 10 (2) ◽  
pp. 168-176
Author(s):  
Krishnasamy Gopinath ◽  
Nagarajan Subbiah ◽  
Muthusamy Karthikeyan

Background: Syzygium densiflorum Wall. ex Wight & Arn (Myrtaceae) has been traditionally used by the local tribes of the Nilgiris, Tamil Nadu, India, for the treatment of diabetes. Objective: This study aimed to isolate the major phytoconstituents from the S. densiflorum fruits and to perform computational studies for chemical reactivity and biological activity of the isolated compound. Materials and Methods: Two different compounds were isolated from ethanolic extract of S. densiflorum fruits and purified using HPLC. The structures of the compounds were elucidated on the basis of their 1H NMR, 13C NMR, 1H-1H COSY, HMBC, HRESIMS, and FT-IR data. Further, the chemical reactivity of the compounds was analyzed by density functional theory calculations and its therapeutic role in diabetic management was examined by comparing the structure of isolated compounds with previously reported bioactive compounds. Results: Of the two compounds ((6,6 & 1-kestopentaose (1) and 6-(hydroxymethyl)-3-[3,4,5- trihydroxy- 6-[(3,4,5-trihydroxyoxan-2-yl)oxymethyl]oxan-2-yl]oxyoxane-2,4,5-triol)(2)). β-glucosidase, β-galactosidase, α-glucosidase and β-amylase inhibition activity of the compounds were predicted by structure activity relationship. Conclusion: Structure-activity relationship analysis was performed to predict the therapeutic role of isolated compounds. These computational studies may be performed to minimize the efforts to determine the therapeutic role of natural compounds.


Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 581
Author(s):  
Ning Dong ◽  
Mengyue Chen ◽  
Qing Ye ◽  
Dan Zhang ◽  
Hongxing Dai

The Ni-loaded cryptomelane-type manganese oxide octahedral molecular sieve (OMS-2) catalysts (xNi/OMS-2: x = 1, 3, 5, and 10 wt%) were prepared by a pre-incorporation method. Physicochemical properties of the as-synthesized materials were characterized by means of various techniques, and their catalytic activities for CO, ethyl acetate, and toluene oxidation were evaluated.The loading of Ni played an important role in improving physicochemical propertiesof OMS-2. Among all of the samples, 5Ni/OMS-2 exhibited the best catalytic activity, with the T90 being 155 °C for CO oxidation at a space velocity (SV) of 60,000 mL/(g·h), 225°C for ethyl acetate oxidation at an SV of 240,000 mL/(g·h), and 300 °C for toluene oxidation at an SV of 240,000 mL/(g·h), which was due to its high Mn3+ content and Oads concentration, good low-temperature reducibility and lattice oxygen mobility, and strong interaction between the Ni species and the OMS-2 support. In addition, catalytic mechanisms of the oxidation of three pollutants over 5Ni/OMS-2 were also studied. The oxidation of CO, ethyl acetate, and toluene over the catalysts took place first via the activated adsorption, then intermediates formation, and finally complete conversion of the formed intermediates to CO2 and H2O.


2014 ◽  
Vol 16 (9) ◽  
pp. 2127-2136 ◽  
Author(s):  
Yuanzhi Tang ◽  
Samuel M. Webb ◽  
Emily R. Estes ◽  
Colleen M. Hansel

Manganese (Mn) oxides, which are generally considered biogenic in origin within natural systems, are the only oxidants of Cr(iii) under typical environmental conditions.


2016 ◽  
Vol 138 (30) ◽  
pp. 9572-9580 ◽  
Author(s):  
Dong Gu ◽  
Jo-Chi Tseng ◽  
Claudia Weidenthaler ◽  
Hans-Josef Bongard ◽  
Bernd Spliethoff ◽  
...  

2015 ◽  
Vol 44 (27) ◽  
pp. 12196-12209 ◽  
Author(s):  
Erica C. M. Ording-Wenker ◽  
Maxime A. Siegler ◽  
Martin Lutz ◽  
Elisabeth Bouwman

High activity for the catalytic oxidation of 3,5-di-tert-butylcatechol was achieved with complexes of ligands that stabilize the biomimetic CuII μ-thiolate complex, hinting at a similarity with the required Cu-oxo intermediates.


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