by Dafné Silva  , Laís Nerys  , Carlos Silva  , Elizabeth Borba  , Tonny Leite  , Teresinha Silva  and Amanda Sena

Received: 27 May 2022;  Published: 25 August 2022;  doi: 10.21926/cr.2203024

Macambira plant (Bromelia laciniosa Mart. Ex Shult. & Schult. f.) is a species belonging to the family Bromeliaceae, which is distributed widely in the hinterlands of northeastern Brazil, from Bahia to Piauí states. The plants of this species contain an enzyme complex named bromelain, which has great potential for therapeutic applications. In the present study, bromelain derived from Bromelia laciniosa leaves was assessed for its thermodynamic properties and in vitro cytotoxic and healing activities. Bro [...]

by Virginia M.R. Menezes  , Gustavo M. Paula  , Liliane A. Lima  , Meiry G.F. Rodrigues  and Fabiano A.N. Fernandes

Received: 05 May 2022;  Published: 16 August 2022;  doi: 10.21926/cr.2203023

In this study, we investigated the oligomerization mechanism of the Fischer-Tropsch synthesis catalyzed by a cobalt-based catalyst supported by SBA-15. The Co/SBA-15 catalyst contained 20% w/w of cobalt. It was prepared by the wet impregnation method and characterized by X-ray diffraction (XRD), N2 adsorption-desorption, temperature-programmed reduction (TPR), and scanning electron microscopy coupled to X-ray energy dispersion spectroscopy (SEM-EDS). The FT synthesis was conducted in a slurry bed reactor operating [...]

by Olushola S. Ayanda  , Cecilia C. Oforkansi  , Omolola H. Aremu  , Oluwakemi E. Ogunjemiluyi  , Ololade L. Olowoyeye  and Cecilia O. Akintayo

Received: 26 June 2022;  Published: 25 July 2022;  doi: 10.21926/cr.2203022

In this study, we investigated the degradation of amido black dye in an aqueous solution using ultra-violet (UV) light catalyzed by iron oxide nanoparticles (nano-Fe). The nano-Fe was synthesized by sodium borohydride reduction of ferric chloride solution and was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray fluorescence spectrophotometry (XRF). The SEM of the nano-Fe showed regular spherical particles, the XRD examination showed a weak and broad peak at Fe (1 1 0), and the [...]

by Anilkumar Mettu  , Ninad Loke  , Vilas Patil  , Rahul Panday  and Sreenivasarao Gajula

Received: 10 January 2022;  Published: 19 July 2022;  doi: 10.21926/cr.2203021

In this study, we present selective hydrocracking of poly (di and tri) aromatic compounds to monoaromatics, such as benzene, toluene, and xylenes (BTX), over a mixture of Pt/Al2O3 and Y zeolites. The polyaromatic compounds feed is a combined simulated model feed, which is similar to light cycle oil (LCO) in composition. The feed is processed in a fixed bed reactor over a catalyst mixture: in the first step, selective hydrogenation of di and tri-aromatic compounds occurs in the presence of Pt/Al2O3 catalyst, followe [...]

by Luiz Felipe da M. Rocha  , Leonardo C. Ferreira  , Maria de Fatima V. Marques  , Rodrigo S. Bitzer  and Marco Antônio Chaer Nascimento

Received: 18 May 2022;  Published: 06 July 2022;  doi: 10.21926/cr.2203020

We synthesized and spectroscopically characterized a new heterotrimetallic {Ti2Ni} ethylene (co)polymerization precatalyst containing one (α-diimine)NiBr2 and two (phenoxy-imine)TiCl4 scaffolds. Its calculated structure was investigated at the DFT B3LYP/LACVP** level. Our calculations showed that the titanium(IV) centers were in a slightly distorted trigonal bipyramidal environment, and the average Ti···Ni distance was 8.76 Å. The precatalyst was used for synthesizing polyethylene a [...]

by Galina Huseynova  , Gulbeniz Muxtarova  , Nushaba Aliyeva  , Gular Gasimova  and Sanubar Rashidova

Received: 05 May 2022;  Published: 05 July 2022;  doi: 10.21926/cr.2203019

This article provides an overview of zeolite-containing catalysts used in the alkylation of benzene and toluene with olefins, isobutane with butenes and butane-butene fractions, gasoline and oil fractions with olefins, propane-propylene, and butane-butylene fractions of catalytic cracking. Zeolites have various types of structures, including BEA, MFI, MWW, FAU, etc., which differ in pore size and the number and location of the channels. High-silica zeolites have a large pore volume, high acidity, good hydrothermal [...]

by Jiarui Fang  , Ziheng Li  , Xiruo Bai  , Yichu Zhang  , Jiahui Liu  , Dan Wang  and Ye Yao

Received: 10 May 2022;  Published: 04 July 2022;  doi: 10.21926/cr.2203018

TiO2 (001) crystal plane exhibits molecular adsorption and photocatalytic activity. The loading capacity of reactive oxygen species present on crystal planes helps in the significant improvement of catalytic activity. The methods of synthesis and conditions of existence significantly affect the molecular adsorption properties of crystal planes, which in turn affects the ability of the system to load reactive oxygen species. Herein, we report the simulation of the molecular adsorption behavior on the TiO2 (001) usin [...]

by Sabira Sabir Ismayilova  and Sabir Qarsh Amirov

Received: 09 January 2022;  Published: 28 June 2022;  doi: 10.21926/cr.2202017

The kinetics of dearomatization of a kerosene fraction processed using a zeolite catalyst (0.9 HZSM-5) at different temperatures (160-200°C), the molar ratio between the aromatic hydrocarbons present in the kerosene fraction and n-decene (1:(0.5-4)), and the reaction time (1-3 h) were studied. Based on the obtained data, a kinetic model for kerosene dearomatization is proposed. It is assumed that the single-center Riedel mechanism is followed. The stage associated with the interaction between n-decene adsorbed on t [...]

by Jia Yu  , Haiyan Jing  , Zongdeng Wu  , Boyuan Liu  , Wu Lei  and Qingli Hao

Received: 29 April 2022;  Published: 21 June 2022;  doi: 10.21926/cr.2202016

The rational design of efficient electrocatalysts for oxygen reduction reaction (ORR) is the key to developing fuel cells and metal-air batteries. Carbon-supported iron-based materials, as the most promising electrocatalysts for ORR, have drawn much attention as they are cost-effective and exhibit high activity. In this work, a three-dimensional (3D) Fe3O4-decorated N-doped graphene aerogel (Fe3O4/NGA) catalyst was synthesized following a simple hydrothermal method which was followed by an annealing process. The co [...]

by Hiromi Matsuhashi

Received: 28 April 2022;  Published: 06 June 2022;  doi: 10.21926/cr.2202015

Solid base catalysts consisting of MgO modified with 10 mol% ZnO (ZnO/MgO) were prepared by depositing zinc(II) acetylacetonate (Zn(acac)2) in polar and nonpolar organic solvents on the surface of MgO and Mg(OH)2. The process was followed by thermal decomposition in air at 773 K over a period of 3 h. The activity of MgO modified with Zn(acac)2 for base-catalyzed retroaldol reaction (the decomposition of diacetone alcohol (4-hydroxy-4-methyl-2-pentanone) to acetone) at 299 K was higher than the activity of unmodifie [...]