scholarly journals Immobilization of β-Glucosidase over Structured Cordierite Monoliths Washcoated with Wrinkled Silica Nanoparticles

Catalysts ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 889 ◽  
Author(s):  
Virginia Venezia ◽  
Aniello Costantini ◽  
Gianluca Landi ◽  
Almerinda Di Benedetto ◽  
Filomena Sannino ◽  
...  

The enzymatic conversion of biomass-derived compounds represents a key step in the biorefinery flowsheet, allowing low-temperature high-efficiency reactions. β-Glucosidases are able to hydrolyze cellobiose into glucose. Wrinkled silica nanoparticles (WSNs) were demonstrated to be a good support for the immobilization of β-glucosidases, showing better performance than free enzymes in batch reaction; on the other hand, immobilized enzyme microreactors (IEMs) are receiving significant attention, because small quantities of reagents can be used, and favorable heat and mass transfer can be achieved with respect to conventional batch systems. In this work, we prepared, characterized, and tested structured enzymatic reactor compounds by a honeycomb monolith, a WSN washcoat, and β-glucosidases as the active phase. Powder and structured materials were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), N2 physisorption, thermogravimetric analysis (TGA), and Fourier-transform infrared spectroscopy (FT-IR). Structured catalysts were tested under both batch and continuous flow reaction conditions and compared to powder catalysts (batch reaction). The WSN washcoat was attached well onto the monolith walls, as suggested by the negligible weight loss after ultrasound treatment; the WSNs preserved their shape, porosity, and individual nature when deposited onto the monolith walls. The immobilized enzyme microreactors proved to be very efficient in hydrolysis of cellobiose to glucose, showing a complete conversion under continuous flow reaction at a batch-equivalent contact time equal to 120 min vs. 24 h obtained in the batch experiments. The apparent KM value showed a 20-fold decrease with respect to the batch process, due to the absence of external diffusive transport limitations.

2015 ◽  
Vol 5 (3) ◽  
pp. 183-189 ◽  
Author(s):  
Olav Bleie ◽  
Michael F. Roberto ◽  
Thomas I. Dearing ◽  
Charles W. Branham ◽  
Olav M. Kvalheim ◽  
...  

2006 ◽  
Vol 15-17 ◽  
pp. 261-266
Author(s):  
Bretislav Šmíd ◽  
Toshiyuki Mori ◽  
M. Takahashi ◽  
Ding Rong Ou ◽  
V. Matolín ◽  
...  

Carbon monoxide (CO) is a significant air pollutant produced in incomplete oxidation of carbon in combustion. From the viewpoint of environmental protection, it is important that the concentration of CO gas is lowered in air. Catalysis is proving to be an effective route for removing this pollutant. Therefore, a design of nano-structured catalysts with high efficiency is required. In the present work, we focus on a development of nano-size CuOx-CeO2 catalysts for CO oxidation reaction. To prepare nano-structured Cu loaded CeO2 catalysts, a combined method of the conventional impregnation and ammonium carbonate co-precipitation was examined. Morphology, crystal phase and surface structure of prepared catalysts were characterized using High-Resolution Transmission Electron Microscopy (HRTEM), Scanning Electron Microscopy (SEM) and Powder X-ray Diffraction (XRD). Catalytic properties of CuOx-CeO2 for CO oxidation were investigated in gas flow reactor system under atmospheric pressure and compared with copper oxide loaded zinc oxide. We expected that nano-structured CuOx-CeO2 catalysts could be used for removing CO produced in a wet reforming reaction of fuel cell applications.


2003 ◽  
Vol 3 (3) ◽  
pp. 273-279 ◽  
Author(s):  
Yuxiang Chen ◽  
Zhigang Xue ◽  
Duo Zheng ◽  
Kun Xia ◽  
Yanzhong Zhao ◽  
...  

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1325
Author(s):  
Zhongwei Gao ◽  
Changqing Pan ◽  
Chang-Ho Choi ◽  
Chih-Hung Chang

Water pollution is a growing global issue; there are many approaches to treating wastewater, including chemical coagulation, physical adsorption, and chemical oxidation. The photocatalysis process has provided a solution for removing pollutants from wastewater, where the pair of the photoelectron and hole works through an asymmetric way to degrade the contaminants under UV irradiation. This method offers an alternative route for treating the pollutant with a lower energy cost, high efficiency, and fewer byproducts. A continuous-flow microfluidic reactor has a channel size from tens to thousands of micrometers, providing uniform irradiation and short diffusion length. It can enhance the conversion efficiency of photocatalysis due to the simple spatial symmetry inside the microreactor channel and among the individual channels. In addition, the bandgap of TiO2, ZnO, or other photocatalyst nanoparticles with symmetric crystal structure can be modified through doping or embedding. In this mini-review, a review of the reported continuous-flow photocatalytic microfluidic reactor is discussed from the perspective of both microreactor design and material engineering.


2016 ◽  
Vol 22 (S3) ◽  
pp. 1080-1081
Author(s):  
Alberto Estevez ◽  
Colin Garvey ◽  
Claudio Ciferri

2010 ◽  
Vol 312 (24) ◽  
pp. 3613-3618 ◽  
Author(s):  
Hiromichi Hayashi ◽  
Takio Noguchi ◽  
Nazrul M. Islam ◽  
Yukiya Hakuta ◽  
Yusuke Imai ◽  
...  

Synthesis ◽  
2018 ◽  
Vol 51 (01) ◽  
pp. 251-257 ◽  
Author(s):  
Antoine Nitelet ◽  
Vanessa Kairouz ◽  
Hélène Lebel ◽  
André Charette ◽  
Gwilherm Evano

A simple continuous flow synthesis of alkenyl chlorides from the corresponding readily available alkenyl iodides in copper reactor tubing is described. A variety of alkenyl chlorides were obtained in good to excellent yields with full retention of the double bond geometry. The reaction time was reduced by a factor of 24–48 compared to the batch process.


2018 ◽  
Vol 266 ◽  
pp. 249-258 ◽  
Author(s):  
Maria Romero-Fernández ◽  
Sonia Moreno-Perez ◽  
Alejandro H. Orrego ◽  
Sandro Martins de Oliveira ◽  
Ramón I. Santamaría ◽  
...  

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