Catalytic Activity in Organic Solvents and Stability of Immobilized Enzymes Depend on the Pore Size and Surface Characteristics of Mesoporous Silica

2000 ◽  
Vol 12 (11) ◽  
pp. 3301-3305 ◽  
Author(s):  
Haruo Takahashi ◽  
Bo Li ◽  
Toshiya Sasaki ◽  
Chie Miyazaki ◽  
Tsutomu Kajino ◽  
...  
2003 ◽  
Vol 125 (43) ◽  
pp. 13032-13033 ◽  
Author(s):  
Masakazu Iwamoto ◽  
Yasuhiro Tanaka ◽  
Naoki Sawamura ◽  
Seitaro Namba

2006 ◽  
Vol 71 (4) ◽  
pp. 339-347 ◽  
Author(s):  
Radivoje Prodanovic ◽  
Nenad Milosavic ◽  
Slobodan Jovanovic ◽  
Tanja Cirkovic-Velickovic ◽  
Zoran Vujcic ◽  
...  

?-Glucosidase from baker?s yeast was immobilized on macroporous copolymers of ethylene glycol dimethacrylate and glycidyl methacrylate, poly(GMA-co-EGDMA) with various surface characteristics and pore sizes ranging from 44 nm to 270 nm. Immobilization was done by glutaraldehyde on the copolymer previously modified with 1,2-diaminoethane. The specific activity of the obtained immobilized enzyme varied from 27 to 81 U/g, depending on the employed copolymer. The half lives of the immobilized enzyme in cosolvents were influenced by the surface characteristics of the copolymer, ranging from 60 to 150 min in 35% methanol and from 10 to 44 min in 45% dimethyl sulphoxide (DMSO). The best stabilities were obtained when the enzyme was immobilized onto a copolymer having a pore size of 48 nm in methanol and 270 nm in DMSO.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yoottapong Klinthongchai ◽  
Seeroong Prichanont ◽  
Piyasan Praserthdam ◽  
Bunjerd Jongsomjit

AbstractMesocellular foam carbon (MCF-C) is one the captivating materials for using in gas phase dehydrogenation of ethanol. Extraordinary, enlarge pore size, high surface area, high acidity, and spherical shape with interconnected pore for high diffusion. In contrary, the occurrence of the coke is a majority causes for inhibiting the active sites on catalyst surface. Thus, this study aims to investigate the occurrence of the coke to optimize the higher catalytic activity, and also to avoid the coke formation. The MCF-C was synthesized and investigated using various techniques. MCF-C was spent in gas-phase dehydrogenation of ethanol under mild conditions. The deactivation of catalyst was investigated toward different conditions. Effects of reaction condition including different reaction temperatures of 300, 350, and 400 °C on the deactivation behaviors were determined. The results indicated that the operating temperature at 400 °C significantly retained the lowest change of ethanol conversion, which favored in the higher temperature. After running reaction, the physical properties as pore size, surface area, and pore volume of spent catalysts were decreased owing to the coke formation, which possibly blocked the pore that directly affected to the difficult diffusion of reactant and caused to be lower in catalytic activity. Furthermore, a slight decrease in either acidity or basicity was observed owing to consumption of reactant at surface of catalyst or chemical change on surface caused by coke formation. Therefore, it can remarkably choose the suitable operating temperature to avoid deactivation of catalyst, and then optimize the ethanol conversion or yield of acetaldehyde.


RSC Advances ◽  
2021 ◽  
Vol 11 (17) ◽  
pp. 10010-10017
Author(s):  
Ping-Chung Kuo ◽  
Zhi-Xun Lin ◽  
Tzi-Yi Wu ◽  
Chun-Han Hsu ◽  
Hong-Ping Lin ◽  
...  

Mesoporous silica films were used as supports with high loading capacity and enzyme activity.


2021 ◽  
Author(s):  
Israel T. Pulido-Díaz ◽  
Alejandro Serrano-Maldonado ◽  
Carlos César López-Suárez ◽  
Pedro A. Méndez-Ocampo ◽  
Benjamín Portales-Martínez ◽  
...  

RhNPs supported on mesoporous silica functionalized with nicotinamide groups provided active hydrogenation catalysts for several functional groups, wherein the shape and size of the RhNPs are maintained after catalysis.


RSC Advances ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 3749-3754 ◽  
Author(s):  
Hongri Suo ◽  
Haohong Duan ◽  
Chunping Chen ◽  
Jean-Charles Buffet ◽  
Dermot O'Hare

Core@shell materials which exhibit hierarchical morphology with ultra high surface area and controllable pore size and structure have been synthesised.


2005 ◽  
Vol 86 (1-3) ◽  
pp. 198-206 ◽  
Author(s):  
Svatopluk Chytil ◽  
Wilhelm R. Glomm ◽  
Elisabeth Vollebekk ◽  
Håkon Bergem ◽  
John Walmsley ◽  
...  

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