scholarly journals Pd-HPW/SiO2 Bi-Functional Catalyst: Sonochemical Synthesis, Characterization, and Effect on Octahydroquinazolinone Synthesis

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1273
Author(s):  
Md. Afroz Bakht ◽  
Mshari. Alotaibi ◽  
Abdulrahman I. Alharthi ◽  
Israf Ud Din ◽  
Abuzer Ali ◽  
...  

A Palladium-doped silica-supported heteropoly acid (HPW) (1%Pd-HPW/SiO2) bi-functional catalyst was produced using ultrasonic and conventional procedures. Both forms of catalyst were characterized with distinct analytical approaches in order to access the advantages of each one. The presence of the required functional groups in the catalyst was confirmed using FT-IR. The crystallinity of ultrasonically generated 1%Pd-HPW/SiO2 was confirmed with XRD. The existence of necessary elements in the catalyst was also suggested by XPS and EDX data. BET was used to calculate the surface area of the ultrasonically synthesized catalyst (395 m2 g−1), and it was found to be greater than that of the non-ultrasonic synthesized catalyst (382 m2 g−1). The N2 adsorption-desorption isotherm indicated mesoporous structures. The SEM morphology at a similar magnification exhibited quite different shapes. In comparison to traditional methods, ultrasonic approaches produce higher yields in less time and use less energy. Furthermore, the effect of the preparation method of the 1%Pd-HPW/SiO2 catalyst was extensively studied with respect to the synthesis of octahydroquinazolinones. Excellent product yields, a fast reaction time, and simple work-up methods are some peculiarities associated with the ultrasonically synthesized catalyst. The recycling study was also investigated and found suitable for up to four reaction cycles.

2021 ◽  
Vol 11 (7) ◽  
Author(s):  
Sabarish Radoor ◽  
Jasila Karayil ◽  
Aswathy Jayakumar ◽  
Jyotishkumar Parameswaranpillai ◽  
Suchart Siengchin

AbstractIn the present work, we have developed a mesoporous silicalite-1 using CMC as a template for the removal of MB from aqueous solution. The synthesized silicalite-1 were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Energy-dispersive X-ray spectroscopy (EDAX) and N2 adsorption–desorption isotherm (BET). XRD and FT-IR analysis confirmed the formation of crystallinity and development of MFI structure in the mesoporous silicalite-1. The adsorption of MB dye on mesoporous silicalite-1 was conducted by batch adsorption method. The effect of various parameters such as adsorbent dosage, initial dye concentration, contact time and temperature on the dye uptake ability of silicalite-1 was investigated. The operating parameters for the maximum adsorption are silicalite-1 dosage (0.1 wt%), contact time (240 min), initial dye concentration (10 ppm) and temperature (30 ℃). The MB dye removal onto mesoporous silicalite-1 followed pseudo-second-order kinetic and Freundlich isotherm. The silicalite-1 exhibits 86% removal efficiency even after six adsorption–desorption cycle. Therefore, the developed mesoporous silicalite-1 is an effective eco-friendly adsorbent for MB dye removal from aqueous environment.


2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Kobra Nikoofar ◽  
Fatemeh Shahriyari

AbstractA simple, straightforward, and ultrasound-promoted method for the preparation of some highly functionalized tetrahydropyridines reported via pseudo five-component reaction of (hetero)aromatic aldehydes, different anilines, and alkyl acetoacetates in the presence of [N-CH2CO2H-3-pic]+HSO4−, as a novel ionic liquid, in green aqueous medium. The IL was synthesized utilizing simple and easily-handled substrates and characterized by FT-IR, 1H NMR, 13C NMR, GC-MASS, FESEM, EDX, and TGA/DTG techniques. The procedure contains some highlighted aspects which are: (a) performing the MCR in the presence of aqua and sonic waves, as two main important and environmentally benign indexes in green and economic chemistry, (b) high yields of products within short reaction times, (c) convenient work-up procedure, (d) preparing the new IL via simple substrates and procedure.


2019 ◽  
Vol 41 (1) ◽  
pp. 72-72
Author(s):  
Jilei Liang Jilei Liang ◽  
Mengmeng Wu Mengmeng Wu ◽  
Hongmei Cai Hongmei Cai ◽  
Hao Wang Hao Wang ◽  
Hua Huang Hua Huang ◽  
...  

Carbon microspheres (CMs) with a diameter of 5-10 μm have been synthesized by hydrothermal carbonization of starch and L-arginine. The surface property and structure of CMs were examined by FT-IR spectra, N2 adsorption-desorption isotherms and SEM images. These characterizations indicated that the L-arginine does not connect into the CMs but it promotes the starch hydrolysis and polymerization-condensation reaction of intermediate, which accelerates the formation of CMs and improves the yield in shorter time. The surface property of CMs determines adsorption capacity for acetic acid. By contrast, the porosity resulted from the carbonization at 500 and#176;C dominates the adsorption capacity for acetic acid.


2012 ◽  
Vol 560-561 ◽  
pp. 294-299
Author(s):  
Xiao Qing Lu ◽  
Min Xing ◽  
Ai Xia Pan ◽  
Yin Yin Wu ◽  
Ji Min Xie ◽  
...  

A novel one-pot catalytic synthesis of 1-benzoylpyrene through acylation of pyrene with benzoyl chloride catalyzed by various Keggin type heteropoly acids (salts) was investigated. Pure 1-benzoylpyrene was obtained and the structure of 1-benzoylpyrene was identified by GC/MS, FT-IR and 1H NMR spectra. H3PW12O40 (PW) was found to be the most active catalyst in the acylation. The yield and the selectivity of 1-benzoylpyrene were up to 97.6 % and 100 %, respectively. The effects of experimental parameters on the catalytic acylation reaction and the recycling performance of PW catalyst were studied. PW catalyst shows well catalytic activity after running for 5 times. The facile product separation and the recycling performance of PW catalyst is expected to contribute to the development of clean and environmentally friendly strategy for the synthesis of 1-benzoylpyrene.


2015 ◽  
Vol 33 (1) ◽  
pp. 163-168 ◽  
Author(s):  
Nitin R. Dighore ◽  
Priyanka L. Anandgaonker ◽  
Suresh T. Gaikwad ◽  
Anjali S. Rajbhoj

AbstractCrystalline MoO3 nanoparticles were obtained by electrochemical synthesis process using tetrapropylammonium bromide as a stabilizer and structure-directing agent in ACN:THF(4:1) solvent. Formation of MoO3 nanoparticles took place at a constant supply current of 14 mA/cm2. These synthesized MoO3 nanoparticles were characterized by UV-Vis spectroscopy, FT-IR spectroscopy, powder X-ray diffraction (XRD), scanning electron microscopy (SEM). So prepared MoO3 nanoparticles were used as a heterogeneous catalyst for the synthesis of 2,6-bis(benzylidene)cyclohexanone derivatives. This protocol offers several advantages, such as simple work-up procedure, recyclability of the catalyst, excellent product yield in a short reaction time and purification of products with a non-chromatographic method.


Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1341 ◽  
Author(s):  
Ruiqi Wang ◽  
Duanyang Li ◽  
Hailong Wang ◽  
Chenglun Liu ◽  
Longjun Xu

S-doped Bi2MoO6 nanosheets were successfully synthesized by a simple hydrothermal method. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), N2 adsorption–desorption isotherms, Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), elemental mapping spectroscopy, photoluminescence spectra (PL), X-ray photoelectron spectroscopy (XPS), and UV-visible diffused reflectance spectra (UV-vis DRS). The photo-electrochemical performance of the samples was investigated via an electrochemical workstation. The S-doped Bi2MoO6 nanosheets exhibited enhanced photocatalytic activity under visible light irradiation. The photo-degradation rate of Rhodamine B (RhB) by S-doped Bi2MoO6 (1 wt%) reached 97% after 60 min, which was higher than that of the pure Bi2MoO6 and other S-doped products. The degradation rate of the recovered S-doped Bi2MoO6 (1 wt%) was still nearly 90% in the third cycle, indicating an excellent stability of the catalyst. The radical-capture experiments confirmed that superoxide radicals (·O2−) and holes (h+) were the main active substances in the photocatalytic degradation of RhB by S-doped Bi2MoO6.


2010 ◽  
Vol 113-116 ◽  
pp. 2053-2056
Author(s):  
Yan Wang ◽  
Rui Qing Liu ◽  
Ai Hua Wen ◽  
Xuan Dong Li

In order to avoid the damage on mesostructure by the high temperature treatment, inorganic titanium species were used as the precursors for the preparation of mesoporous TiO2 of crystalline framework at mild conditions. The influences of the precursor, additive, reaction pH and temperature on phase and textural structures of the products were investigated. The samples were characterized by XRD, N2 adsorption/desorption, FT-IR and SEM. The results show that anatase mesoporous TiO2 with large surface area could be obtained without calcination with Ti(SO4)2 as precursor or TiCl4 when SO42- was added. And the template could be completely removed by Soxhlet extraction.


2019 ◽  
Vol 56 (3) ◽  
pp. 420-435 ◽  
Author(s):  
W. Li ◽  
M.R. Coop

Safety problems have concerned many researchers studying tailings dams in recent years, as they have a high risk of failure due to liquefaction. Existing analysis of liquefaction in tailings within a critical state framework has relied on the critical state line (CSL) being unique in the volumetric plane. However, recent advances have highlighted a so-called “transitional” behaviour in which the location of the normal compression line (NCL) and CSL is a function of the density of the soils at deposition. This paper presents a detailed investigation of the mechanics of tailings taken from three locations of an iron tailings impoundment. Reconstituted samples were prepared by different methods and at different densities. No transitional behaviour was found, although the results show that the rate of convergence of the compression curves changes, with the finest pond material reaching a unique NCL earliest. The preparation method was found not to have a large effect on the behaviour for these tailings. Unique CSLs could be clearly identified for all the three tailings, but with different shapes, giving rise to a changing susceptibility to liquefaction. This susceptibility tends to increase from the pond to the upper beach.


Proceedings ◽  
2019 ◽  
Vol 16 (1) ◽  
pp. 26
Author(s):  
Patrycja Wilczewska ◽  
Aleksandra Bielicka-Giełdoń ◽  
Agnieszka Fiszka Borzyszkowska ◽  
Aleksandra Pieczyńska ◽  
Ewa Maria Siedlecka

A series of Bi4O5Br2 photocatalysts were prepared via an innovation method of synthesis with ionic liquids (ILs). The crystal structures were investigated by X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR). The Field Emission Scanning Electron Microscope (FE-SEM) images illustrated the unique structure of prepared photocatalysts. The photocatalysts were also characterized by N2 adsorption-desorption analysis, X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectra (UV-vis/DRS) and photoluminescence spectra (PL). The role of ILs in synthesis of Bi4O5Br2 on morphology and photocatalytic properties were investigated. Rhodamine B, 5-fluorouracil and chromium (VI) were used as the model micropollutants to evaluated adsorption capacity, photooxidation and photoreduction ability of prepared Bi4O5Br2 under artificial solar light. This work provided a new thought for enhanced photocatalytic activity of bismuth oxybromide photocatalysts.


Catalysts ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 155 ◽  
Author(s):  
Zhenheng Diao ◽  
Lushi Cheng ◽  
Xu Hou ◽  
Di Rong ◽  
Yanli Lu ◽  
...  

Hierarchical HZSM-5 membranes were prepared on the inner wall of stainless steel tubes, using amphiphilic organosilane (TPOAC) and mesitylene (TMB) as a meso-porogen and a swelling agent, respectively. The mesoporosity of the HZSM-5 membranes were tailored via formulating the TPOAC/Tetraethylorthosilicate (TPOAC/TEOS) ratio and TMB/TPOAC ratio, in synthesis gel, and the prepared membranes were systematically characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), N2 adsorption–desorption, N2 permeation, inductively coupled plasma (ICP), in situ fourier transform infrared (FT-IR), ammonia temperature-programmed desorption (NH3-TPD), etc. It was found that the increase of the TPOAC/TEOS ratio promoted a specific surface area and diffusivity of the HZSM-5 membranes, as well as decreased acidity; the increase of the TMB/TPOAC ratios led to an enlargement of the mesopore size and diffusivity of the membranes, but with constant acid properties. The catalytic performance of the prepared HZSM-5 membranes was tested using the catalytic cracking of supercritical n-dodecane (500 °C, 4 MPa) as a model reaction. The hierarchical membrane with the TPOAC/TEOS ratio of 0.1 and TMB/TPOAC ratio of 2, exhibited superior catalytic performances with the highest activity of up to 13% improvement and the lowest deactivation rate (nearly a half), compared with the microporous HZSM-5 membrane, due to the benefits of suitable acidity, together with enhanced diffusivity of n-dodecane and cracking products.


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