The influence of surface physical-chemical characteristics of Chilean natural zeolite on the catalytic ozonation of toluene is presented in this article. Surface characteristics of natural zeolite were modified by acid treatment with hydrochloric aci...
Ionic liquid with both Lewis and Brønsted acid sites has been synthesized and its catalytic activities for Michael addition were carefully studied. The novel ionic liquid was stable to water and could be used in aqueous solution. The molar ratio of t...
Beta zeolites with Si/Al around 14 were prepared using three new alkali-free synthesis methods based on the application of amorphous aluminosilicate precursor and calcined in ammonia or air. All samples exhibit structural and textural properties of s...
Two different synthesis methods to obtain hierarchical Beta zeolite are investigated: direct synthesis using cetyltrimethylammonium bromide (CTAB) as a mesoporous template and post-synthesis desilication by etching with NaOH and TPAOH. The main focus...
Volatile organic compounds (VOCs) are responsible for damage to health due to their carcinogenic effects. Catalytic ozonation using zeolite appears as a valuable process to eliminate VOCs from industrial emissions at room temperature. For full-scale...
The purposes of this study are to investigate the effect of metal (Co and Mo) impregnation to ZSM-5 catalysts on the Brønsted to Lewis (B/L) ratio as the active sites of cracking reaction, and the catalysts’ performance testing for palm oil cracking...
Catalytic cracking of hexane over steamed ZSM-5 is studied under steady state and dynamic conditions to elucidate the role of the active sites on the product distribution. The product distribution from the riser simulator representing the dynamic sta...
The conversion of ethanol towards ethylene and diethyl ether in the presence of catalysts requires special consideration from the perspective of green chemistry. Ethanol dehydration was studied on a complex titanium phosphate MAlTiP (M0.5(1+x)AlxTi2-...
The use of solids acids in the synthesis of ethers suitable to be used as fuels or fuel additives were reviewed in a critical way. In particular, the role of Brønsted and Lewis acid sites was highlighted to focus on the pivotal role of the aci...
A set of Y-type zeolites with Si/Al atomic ratios between 7–45 were studied as catalysts in the aminocyclization reaction between acrolein and ammonia to produce pyridine and 3-picoline. The catalytic activity tests at 360 °C revealed that...
Unique structural and chemical properties, such as ion exchange, developed inner surface, etc., as well as the wide possibilities and flexibility of regulating these properties, cause a keen interest in zeolites. They are widely used in industry as m...
The Lewis acidic framework Ti sites in Ti-Beta and Si-Beta catalysts were compared by FT-IR and NMR characterization methods before they were applied to the conversion of four butenes. The results showed that Si-Beta has fewer Lewis acid sites and ab...
In the present study, an acid catalyst (UiO-66-SO3H) with Brønsted and Lewis acid sites was synthesised for the preparation of highly efficient biodiesel from oleic acid and methanol using chlorosulphonic acid sulfonated metal–organic fr...
The feasibility of fabricating better solid acid catalysts using nonthermal plasma (NTP) technology for biobased acrolein production is demonstrated. NTP discharge exposure was integrated in catalyst fabrication in air or argon atmosphere. The fabric...
The oxidation of benzene to phenol (BTOP) with N2O as the oxidant has been studied with a variety of Fe/ZSM-5 catalysts. The literature has conclusively proven that Fe2+ sites are the active sites. However, some studies have suggested that the Lewis...
This review puts the development of molecular modeling methods in the context of their applications to zeolitic active sites. We attempt to highlight the utmost necessity of close cooperation between theory and experiment, resulting both in advances...
12-Tungstophosphoric acid supported on nanosilica (TPA/SiO2) was employed as a catalyst for the tertiary butylation of p-cresol using tertiary butanol as an alkylating agent. The TPA/SiO2 catalyst was synthesized using the wet impregnation method fol...
The number and the strength of acid sites in catalysts have paramount importance on their efficiency. In zeolites chemistry, increased content of framework Al in zeolites gives a higher number of strong acid sites. Their strength can be a disadvantag...
A series of unique tunable aryl-imidazolium magnetic ionic liquids (MILs) with dual acidity that contain both Brønsted and Lewis acidic sites (abbreviated as B-L MILs) were synthesized and characterized using nuclear magnetic resonance and mas...
5-hydroxymethylfurfural (5-HMF) is an important platform molecule for the synthesis of high-added value products. Several synthesized clay materials, such as mesoporous hectorite and fluorohectorite, in addition to commercial montmorillonite K-10, ha...
Sustainable lignosulfonate was employed as a key component for coordinating with various metal ions, affording metal-coordinated lignosulfonate catalysts (Hf-LigS) for hexose transformation. We first investigated the contribution of bare or tandem Le...
Aligned with circular bioeconomy principles, which aim to establish closed-loop systems that maximize resource utilization and renewal while minimizing waste, this study developed and characterized innovative catalysts derived from waste almond shell...
The catalytic deoxygenation mechanism of fatty acid esters on a Lewis acid site of ZSM-5 zeolite was elucidated via density functional theory (DFT) by using a methyl butyrate (MB) as the model compound for fatty acid esters. The configurations of the...
It is crucial to identify the structures of active sites to understand how catalysts function and to use that understanding to develop better catalytic materials. ZSM-5 zeolites with dominant Al(IV)-2 sites have been developed in this work. 1H-27Al 2...
Zeolites are widely used acid catalysts in research and in industrial processes. The catalytic performance of these materials is affected by the nature and concentration of Brønsted and Lewis acid sites. The balance between these types of acti...
Aqueous-phase acid-catalyzed reactions are essential for the conversion of cellulose-based biomass into chemicals. Brønsted acid and Lewis acid play important roles for these reactions, including hydrolysis of saccharides, isomerization and ep...
Regulating the acid property of zeolite is an effective strategy to improve dehydration of intermediate alcohol, which is the rate-determining step in hydrodeoxygenation of lignin-based phenolic compounds. Herein, a commercial Hβ (SiO2/Al2O3 = 25) wa...
A series of ZnSnPt supported defective MFI zeolites with different SiO2/Al2O3 ratios (30, 110, 700, and ∞) and hydroxyl nests concentration were prepared and characterized by multiple techniques including scanning electron microscopy (SEM), nit...
In this study, a Brönsted–Lewis bifunctional acidic catalyst PW/UiO/CNTs-OH was synthesized via the hydrothermal method. The parameters for the esterification reaction of oleic acid with methanol catalyzed by PW/UiO/CNTs-OH were optimized...
In this work, some physical mixtures of Nb2O5·nH2O and NbOPO4 were prepared to study the role of phosphate groups in the total acidity of samples and in two reactions involving carbohydrate biomass: hydrolysis of polyfructane and dehydration of fruct...
A raw montmorillonite (Mt) was submitted to different acidic activation times in order to investigate the influence of the strength and the nature (Brønsted and Lewis) of acidic sites on the synergistic action with an intumescent formulation (...
The response matrix, as metal oxide nanostructure decorated n-type semiconductor interfaces are modified in situ through direct amination and through treatment with organic sulfides and thiols, is demonstrated. Nanostructured TiO2, SnOx, NiO and CuxO...
Herein, we report the function of copper sites in Cu-SSZ-13, Cu-ZSM-5 and Cu-Beta catalysts with the same Si/Al ratio (14) and Cu/Al ratio (0.4) on selective catalytic reduction of NO with NH3 (NH3-SCR) and reveal the relationship between active site...
Aiming to obtain chemicals from renewable sources to mitigate global warming, the catalytic pyrolysis of tamarind pulp, obtained from juice industries, was studied. Catalysts based on HZSM-5 zeolite prepared from rice husk ash using ultrasound, micro...
This study addresses the critical issue of environmental pollution from plastic waste by investigating an effective chemical recycling method for polyethylene terephthalate (PET) via neutral catalytic hydrolysis. We utilized a recoverable and regener...
5-Hydroxymethylfurfural (HMF) is one of the most important lignocellulosic biomass-derived platform molecules for production of renewable fuel additives, liquid hydrocarbon fuels, and value-added chemicals. The present work developed niobium oxides (...
The catalytic fast pyrolysis (CFP) of bio-derived furans offers a promising approach for sustainable aromatic production. ZSM-5 modified by different metal species (Zn, Mo, Fe, and Ga) was employed in the CFP of bio-derived furans for enhancing aroma...
Coke formation on n-butene cracking catalyst is the main reason for the reducing of its lifetime. To study the effects of acidity and textural properties on the coke formation process, a series of HY zeolite-type catalysts were prepared by ammonium h...
The Meerwein–Ponndorf–Verley (MPV) reaction is an environmentally-friendly process consisting of the reduction of a carbonyl compound through hydrogen transfer from a secondary alcohol. This work deals with MPV reduction of furfural to fu...
Lactic acid is an important platform feedstock for synthesizing various chemicals. Lactic acid is normally converted from any sugar such as glucose, and Sn-β zeolite is an effective catalyst. In this study, β zeolite with different Si/Al ra...
Pyrolysis bio-oils contain significant amounts of carboxylic acids which limit their utility as biofuels. Ketonisation of carboxylic acids within biomass pyrolysis vapours is a potential route to upgrade the energy content and stability of the result...
ZSM-5 zeolites with varying aluminum content were subjected to steam treatments of different severities by adjusting the temperature, duration, and water vapor pressure. The steamed samples were characterized using a range of analytical techniques. A...
The desilication of zeolite Y (of Si/Al = 31) that was previously dealuminated by steaming and acid treatment was studied. Desilication of zeolites of high Si/Al module in alkali solutions extracts both Si and Al from zeolite crystals, but while Si r...
Furfural is a platform molecule that can be catalytically converted using a cascade series of reactions into levulinic esters, essential compounds used as fuel additives. Bifunctional catalysts containing Lewis and Brønsted acid sites such as...
A series of Pt/WOx-ZrO2-TiO2 catalysts with different Ti/Zr molar ratios was prepared by an evaporation induced self-assembly method, and used to efficient hydrogenolysis of glycerol to 1-PO and 1,3-PDO. BET, XRD, Raman, TEM, XPS and Py-IR were emplo...
The effect of the thermal treatment of some zeolitic materials was studied on oxidative dehydrogenation (ODH) of n-octane. Gallium containing faujasite catalysts were synthesized using isomorphic substitution, specifically, a galosilicalite (Ga-BaY(S...
The Paal-Knorr reaction of acetonylacetone with primary amines catalyzed by CATAPAL 200 under conventional heating at 60 °C for 45 min afforded N-substituted pyrroles in 68–97% yields. The pyrrole 3g was studied by single-crystal and powder X-ray dif...
Nb-based catalysts supported on porous silica with different textural properties have been synthesized, characterized, and tested in the one-pot reaction of furfural to obtain valuable chemicals. The catalytic results reveal that the presence of fluo...
A commercially available attapulgite sample (Red Attapulgite) was acid-pretreated to enhance its catalytic activity. It turned out to efficiently facilitate the dehydration of a range of substituted alcohols. The dehydration of the primary alcohol wa...
Ionic liquids with [BMIM], [Et3NH], and [BPy] cations and AlnCl−3n+1, ZnnCl−2n+1, and CunCl−n+1 anions were used as the catalysts for the chlorination of toluene with Cl2. The ZnnCl−2n+1 containing ionic liquids with high Lewi...
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