scholarly journals Bimetallic Pd-Au/SiO2 Catalysts for Reduction of Furfural in Water

Catalysts ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 444 ◽  
Author(s):  
Magdalena Modelska ◽  
Michal J. Binczarski ◽  
Zbigniew Kaminski ◽  
Stanislaw Karski ◽  
Beata Kolesinska ◽  
...  
Keyword(s):  
Solid Solution ◽  
Reaction Mechanism ◽  
High Activity ◽  
Main Product ◽  
Waste Biomass ◽  
Catalytic Systems ◽  
Tof Sims ◽  
Spent Grain ◽  
Brewery's Spent Grain ◽  
Hydrolysis Of

Catalytic systems based on bimetallic Pd-Au particles deposited on SiO2 were prepared by ultrasonically assisted water impregnation and used in the hydrogenation of furfural obtained by the acidic hydrolysis of waste biomass (brewery’s spent grain) in aqueous phase. Pd-Au/SiO2 catalysts containing 50 g of Pd and 2–100 g of Au per 1 kg of catalyst were characterized by high activity in the studied process and, depending on the Pd/Au ratio, selectivity to 2-methyloxolan-2-ol. The modification of 5%Pd/SiO2 by Au leads to the formation of dispersed Au-Pd solid solution phases, which was confirmed by XRD, XPS, ToF-SIMS, SEM-EDS, and H2-TPR techniques. The effect of dilution of surface palladium by gold atoms is probably crucial for modification of the reaction mechanism and formation of 2-methyloxolan-2-ol as the main product.

scholarly journals Mini-Review on the Synthesis of Furfural and Levulinic Acid from Lignocellulosic Biomass

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1234
Author(s):  
Zhiwei Jiang ◽  
Di Hu ◽  
Zhiyue Zhao ◽  
Zixiao Yi ◽  
Zuo Chen ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Lignocellulosic Biomass ◽  
Catalytic System ◽  
Levulinic Acid ◽  
Value Added ◽  
Environmental Issues ◽  
Alternative Route ◽  
Catalytic Systems ◽  
Renewable Biomass ◽  
Platform Chemicals

Efficient conversion of renewable biomass into value-added chemicals and biofuels is regarded as an alternative route to reduce our high dependence on fossil resources and the associated environmental issues. In this context, biomass-based furfural and levulinic acid (LA) platform chemicals are frequently utilized to synthesize various valuable chemicals and biofuels. In this review, the reaction mechanism and catalytic system developed for the generation of furfural and levulinic acid are summarized and compared. Special efforts are focused on the different catalytic systems for the synthesis of furfural and levulinic acid. The corresponding challenges and outlooks are also observed.

Reaction Mechanism for CCl2F2 Catalytic Decomposition over MoO3/ZrO2

2013 ◽  
Vol 295-298 ◽  
pp. 326-330 ◽  
Author(s):  
Tian Cheng Liu ◽  
Yu Jiao Guo ◽  
Ping Ning ◽  
Ming Long Yuan
Keyword(s):  
Reaction Mechanism ◽  
Main Product ◽  
Solid Acid ◽  
Fixed Bed ◽  
Catalytic Decomposition ◽  
Strong Acid ◽  
Acid Sites ◽  
Fixed Bed Reactor ◽  
Surface Intermediate ◽  
Strong Acid Sites

Catalytic hydrolysis decomposition of dichlorodifluoromethane (CCl2F2) in the presence of water vapor and oxygen was studied over a series of solid acids using a fixed-bed reactor. Solid acid MoO3/ZrO2 displayed the highest activity, over which the conversion of CCl2F2 reached 100 % at 250 °C. CO2 was the main-product and the selectivity to CClF3 remained lower than 28.0 %. CO was not detected as by-product. The decomposition activity depended on the calcination temperature and the ZrO2 content. The activity of solid acid MoO3/ZrO2 correlates well with its specific surface area and the amount of medium-strong acid sites on the surface. To explain the reaction mechanism for CCl2F2 catalytic decomposition over MoO3/ZrO2, a surface intermediate, Osurface-CF2-Osurface is proposed.

scholarly journals Erratum to: “Self-assembling catalytic systems based on new amphiphile containing purine fragment, exhibiting substrate specificity in hydrolysis of phosphorus acids esters”

2017 ◽  
Vol 87 (7) ◽  
pp. 1649-1649
Author(s):  
D. A. Samarkina ◽  
D. R. Gabdrakhmanov ◽  
V. E. Semenov ◽  
F. G. Valeeva ◽  
L. M. Gubaidullina ◽  
...  
Keyword(s):  
Substrate Specificity ◽  
Catalytic Systems ◽  
Self Assembling ◽  
Hydrolysis Of

Evaluation of thermomechanical pretreatment for enzymatic hydrolysis of pure microcrystalline cellulose and cellulose from Brewers’ spent grain

2011 ◽  
Vol 54 (3) ◽  
pp. 305-310 ◽  
Author(s):  
Guillaume Pierre ◽  
Frédéric Sannier ◽  
Romain Goude ◽  
Armelle Nouviaire ◽  
Zoulikha Maache-Rezzoug ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Microcrystalline Cellulose ◽  
Spent Grain ◽  
Hydrolysis Of

Vinyl ether hydrolysis. XVII. Oxacyclonon-2,8-diene and the question of the unorthodox reaction mechanism for 9-methoxyoxacyclonon-2-ene

1984 ◽  
Vol 62 (1) ◽  
pp. 74-76 ◽  
Author(s):  
R. A. Burt ◽  
Y. Chiang ◽  
A. J. Kresge ◽  
S. Szilagyi
Keyword(s):  
Reaction Mechanism ◽  
Vinyl Ether ◽  
Membered Ring ◽  
Specific Rate ◽  
Ether Group ◽  
Reaction Proceeds ◽  
Great Reactivity ◽  
Rate Of Hydrolysis ◽  
Acid Catalyzed ◽  
Hydrolysis Of

The acid-catalyzed hydrolysis of the nine-membered ring cyclic vinyl ether, oxacyclonon-2,8-diene, occurs with a normal isotope effect, [Formula: see text], which indicates that this reaction proceeds by the conventional vinyl ether hydrolysis mechanism involving rate-determining proton transfer to carbon. The specific rate of this reaction, [Formula: see text], may then be used to show that there is no significant ring-size effect on the rate of hydrolysis of a vinyl ether group in a nine-membered ring. The previously noted unusually great reactivity of the vinyl ether group in 9-methoxyoxacyclonon-2-ene, for which an unorthodox reaction mechanism has been claimed, must therefore be due to some other cause.

Breakthrough in hydrolysis of waste biomass by physico-chemical pretreatment processes for efficient anaerobic digestion

Chemosphere ◽  
2022 ◽  
pp. 133617
Author(s):  
Preethi ◽  
Rajesh Banu J ◽  
Sunita Varjani ◽  
Sivashanmugam P ◽  
Vinay Kumar Tyagi ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Waste Biomass ◽  
Chemical Pretreatment ◽  
Physico Chemical ◽  
Hydrolysis Of ◽  
Pretreatment Processes

The crystal structure of human mitochondrial 3-ketoacyl-CoA thiolase (T1): insight into the reaction mechanism of its thiolase and thioesterase activities

2014 ◽  
Vol 70 (12) ◽  
pp. 3212-3225 ◽  
Author(s):  
Tiila-Riikka Kiema ◽  
Rajesh K. Harijan ◽  
Malgorzata Strozyk ◽  
Toshiyuki Fukao ◽  
Stefan E. H. Alexson ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Reaction Mechanism ◽  
Active Site ◽  
Quaternary Structure ◽  
Fatty Acyl ◽  
Physiological Importance ◽  
Loop Domain ◽  
Solution Studies ◽  
Hydrolysis Of ◽  
Insight Into

Crystal structures of human mitochondrial 3-ketoacyl-CoA thiolase (hT1) in the apo form and in complex with CoA have been determined at 2.0 Å resolution. The structures confirm the tetrameric quaternary structure of this degradative thiolase. The active site is surprisingly similar to the active site of theZoogloea ramigerabiosynthetic tetrameric thiolase (PDB entries 1dm3 and 1m1o) and different from the active site of the peroxisomal dimeric degradative thiolase (PDB entries 1afw and 2iik). A cavity analysis suggests a mode of binding for the fatty-acyl tail in a tunnel lined by the Nβ2–Nα2 loop of the adjacent subunit and the Lα1 helix of the loop domain. Soaking of the apo hT1 crystals with octanoyl-CoA resulted in a crystal structure in complex with CoA owing to the intrinsic acyl-CoA thioesterase activity of hT1. Solution studies confirm that hT1 has low acyl-CoA thioesterase activity for fatty acyl-CoA substrates. The fastest rate is observed for the hydrolysis of butyryl-CoA. It is also shown that T1 has significant biosynthetic thiolase activity, which is predicted to be of physiological importance.

Theoretical study on the reaction mechanism for the hydrolysis of esters and amides under acidic conditions

Tetrahedron ◽  
2007 ◽  
Vol 63 (5) ◽  
pp. 1264-1269 ◽  
Author(s):  
Kenzi Hori ◽  
Yutaka Ikenaga ◽  
Kouichi Arata ◽  
Takanori Takahashi ◽  
Kenji Kasai ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Theoretical Study ◽  
Acidic Conditions ◽  
Hydrolysis Of Esters ◽  
Hydrolysis Of

scholarly journals New methods of acid hydrolysis of cellulose and plant raw materials

2021 ◽  
Vol 57 (1) ◽  
pp. 119-128
Author(s):  
V. S. Boltovsky
Keyword(s):  
Acid Hydrolysis ◽  
Plant Biomass ◽  
Raw Materials ◽  
Agricultural Waste ◽  
Feed Additives ◽  
Process Conditions ◽  
Catalytic Systems ◽  
Plant Raw Materials ◽  
Hydrolysis Of Cellulose ◽  
Hydrolysis Of

Prospects for the development of hydrolysis production are determined by the relevance of industrial use of plant biomass to replace the declining reserves of fossil organic raw materials and increasing demand for ethanol, especially for its use as automobile fuel, protein-containing feed additives that compensate for protein deficiency in feed production, and other products. Based on the review of the research results presented in the scientific literature, the analysis of modern methods of liquid-phase acid hydrolysis of cellulose and various types of plant raw materials, including those that differ from traditional ones, is performed. The main directions of increasing its efficiency through the use of new catalytic systems and process conditions are identified. It is shown that the most promising methods for obtaining monosaccharides in hydrolytic processing of cellulose and microcrystalline cellulose, pentosan-containing agricultural waste and wood, are methods for carrying out the process at elevated and supercritical temperatures (high-temperature hydrolysis), the use of new types of solid-acid catalysts and ionic liquids. 

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