scholarly journals Deactivation of solid catalysts in liquid media: the case of leaching of active sites in biomass conversion reactions

2015 ◽  
Vol 17 (8) ◽  
pp. 4133-4145 ◽  
Author(s):  
Irantzu Sádaba ◽  
Manuel López Granados ◽  
Anders Riisager ◽  
Esben Taarning
Keyword(s):  
Liquid Phase ◽  
Active Sites ◽  
Biomass Conversion ◽  
Liquid Media ◽  
Solid Catalysts ◽  
Specific Focus ◽  
Catalytic Processes

This review is aimed to be a brief tutorial covering the deactivation of solid catalysts in the liquid phase, with specific focus on leaching, which can be especially helpful to researchers not familiarized with catalytic processes in the liquid phase.

ChemInform Abstract: Deactivation of Solid Catalysts in Liquid Media: The Case of Leaching of Active Sites in Biomass Conversion Reactions

ChemInform ◽  
2015 ◽  
Vol 46 (40) ◽  
pp. no-no
Author(s):  
Irantzu Sadaba ◽  
Manuel Lopez Granados ◽  
Anders Riisager ◽  
Esben Taarning
Keyword(s):  
Active Sites ◽  
Biomass Conversion ◽  
Liquid Media ◽  
Solid Catalysts

scholarly journals Biodiesel production from alternative raw materials using a heterogeneous Low Ordered Biosilicified Enzyme as biocatalyst

2020 ◽  
Author(s):  
Gabriel Orlando Ferrero ◽  
Edgar Maximiliano Sánchez Faba ◽  
Griselda Alejandra Eimer
Keyword(s):  
Active Sites ◽  
Heterogeneous Catalysts ◽  
Raw Materials ◽  
Biomass Conversion ◽  
High Water ◽  
Raw Material ◽  
Biodiesel Production ◽  
Waste Frying Oil ◽  
Solid Catalysts ◽  
Pork Fat

Abstract Background: Nowadays, as an alternative to the production of fuels and chemicals from the fossil platform, renewable feedstocks are widely investigated. For biomass conversion, a new generation of catalysts with specific characteristics such as high activity and selectivity, easy recovery and reusability is necessary. The design of highly efficient and stable heterogeneous catalysts represents a challenge in this field, mainly to overcome current energy and environmental issues. The combination of enzymatic and heterogeneous inorganic catalysis generates an unprecedented platform that combines the advantages of both. Among the techniques for producing solid catalysts, enzymatic mineralization with an organic silicic precursor to obtain hybrid biocatalysts (biosilicification) is highlighted. This technique can provide exceptional stability to the biocatalyst in drastic conditions of use.Results: Then, under these criteria, this work presents the one-step synthesis of a solid enzymatic catalyst, denominated Low Ordered Biosilicified Enzyme (LOBE) due to their structural properties. Pseudomonas Fluorescens lipase forms aggregates that are contained in the heart of a silicon-covered micelle, providing active sites with the ability to process different raw materials (commercial sunflower and soybean oil, Jatropha excisa oil, waste frying oil, residual soybeans, and pork fat) to produce first and second generation biodiesel. Obtaining yields between 81 and 93% by weight depending on the used raw material.Conclusions: Therefore, refined, non-edible and residual oils (with high water and free fatty acid contents) can be transformed into biodiesel through LOBE catalysts with commercial ethanol as co-substrate.

Probing active sites in solid catalysts for the liquid-phase epoxidation of alkenes

1994 ◽  
pp. 2279 ◽  
Author(s):  
Gopinathan Sankar ◽  
Fernando Rey ◽  
John Meurig Thomas ◽  
G. Neville Greaves ◽  
Avelino Corma ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Active Sites ◽  
Solid Catalysts ◽  
Epoxidation Of Alkenes ◽  
Liquid Phase Epoxidation

Physicochemical and Catalytic Properties of Spinels Formed by Solid-Solid Interaction Between Fe2O3and V2O5

1996 ◽  
Vol 61 (8) ◽  
pp. 1131-1140 ◽  
Author(s):  
Abd El-Aziz Ahmed Said
Keyword(s):  
Vanadium Oxide ◽  
Active Sites ◽  
Catalyst Surface ◽  
Catalytic Properties ◽  
Flow System ◽  
Oxide Catalysts ◽  
X Ray Diffraction ◽  
Selective Catalyst ◽  
X Ray ◽  
Solid Catalysts

Vanadium oxide catalysts doped or mixed with 1-50 mole % Fe3+ ions were prepared. The structure of the original samples and those calcined from 200 up to 500 °C were characterized by TG, DTA, IR and X-ray diffraction. The SBET values and texture of the solid catalysts were investigated. The catalytic dehydration-dehydrogenation of isopropanol was carried out at 200 °C using a flow system. The results obtained showed an observable decrease in the activity of V2O5 on the addition of Fe3+ ions. Moreover, Fe2V4O13 is the more active and selective catalyst than FeVO4 spinels. The results were correlated with the active sites created on the catalyst surface.

3D Porous Nb2C MXene/Reduced Graphene Oxide Aerogel Coupled with NiFe Alloy Nanoparticles for Wearable Zn–Air Batteries

2021 ◽  
Author(s):  
Hang Lei ◽  
Shangjing Yang ◽  
Runquan Lei ◽  
Qing Zhong ◽  
Qixiang Wan ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Catalytic Activity ◽  
Reduced Graphene Oxide ◽  
Active Sites ◽  
Alloy Nanoparticles ◽  
Reduced Graphene ◽  
Reduced Graphene Oxide Aerogel ◽  
Graphene Oxide Aerogel ◽  
Catalytic Processes

Insufficient catalytic activity and self-restacking of 2D MXenes during catalytic processes would lead to limited number of active sites, sluggish ionic kinetics and poor durability, extremely restricting its application in...

Catalysis in Alkylation of Benzene With Ethene and Propene to Produce Ethylbenzene and Isopropylbenzene

2020 ◽  
pp. 1-47
Author(s):  
Mohammed C. Al-Kinany ◽  
Saeed M. Alshihri ◽  
Saud A. Aldrees ◽  
Eyad A. Alghilan ◽  
Sami D. Aldrees ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Gas Phase ◽  
Bronsted Acids ◽  
Solid Catalysts ◽  
Alkylation Of Benzene ◽  
History Of

The alkylation of benzene with ethylene or propylene to form ethylbenzene (EB) or cumene is an industrially significant transformation. EB is used as an intermediate in the manufacture of styrene, which in turn is an important in the manufacture of many kinds of polymers. The primary use of cumene is in the co-production of phenol and acetone, which in turn are important in the manufacture of many kinds of chemicals and polymers. In industry, EB and cumene are mainly manufactured by the alkylation of benzene with ethene or propene via two methods, the gas and the liquid phase in the presence of Lewis and Brønsted acids. The development of efficient solid catalysts has gained much attention over the last decades. The objective of this chapter is to provide an overview of the history of the alkylation of benzene with ethene and propene, the development of homogeneous and heterogeneous Lewis and Brønsted acids and zeiolite catalysts, the liquid and gas phase alkylation processes, and the industrial technologies for EB and cumene production.

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