scholarly journals Bentonites Modified with Phosphomolybdic Heteropolyacid (HPMo) for Biowaste to Biofuel Production

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1431 ◽  
Author(s):  
Alex de Nazaré de Oliveira ◽  
Marco Aurélio Barbosa de Lima ◽  
Luíza Helena de Oliveira Pires ◽  
Moisés Rosas da Silva ◽  
Patrícia Teresa Souza da Luz ◽  
...  

Two bentonites from Paraíba (Northeastern Brazil) were impregnated with heteropoly phosphomolybdic H3PMo12O40 (HPMo). The materials produced were characterized by various techniques such as N2 adsorption-desorption (specific surface area, SSA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Thermogravimetric analysis (TGA/DTG), Scanning Electron Microscopy (SEM) equipped with Dispersive Energy X-ray spectroscopy (EDS), ultraviolet-visible spectroscopy (UV-vis), acid-base titration analysis. The catalytic activity of these materials was tested in the esterification of a waste from palm oil deodorization and the main results obtained (about 93.3% of conversion) indicated that these materials have potential to act as heterogeneous solid acid catalysts. The prepared materials exhibited satisfactory catalytic performance even after a very simple recycling process in three reuse cycles, without significant loss of their activities.

2013 ◽  
Vol 634-638 ◽  
pp. 696-700
Author(s):  
Lin Jiu Xiao ◽  
Peng Li ◽  
Yong Gang Sheng

A series of Ti(SO4)2/γ-Al2O3 catalysts were prepared by impregnation method and the catalytic performance of these catalysts in 1-butene oligomerization was investigated. The heat treatment temperature played great influences on the catalytic performance of these catalysts in the oligomerization. 90.1 wt.% conversion of 1-butene and 92.2 wt.% selectivity of dimers were obtained on Ti(SO4)2/γ-Al2O3(450) catalyst at 80 °C, 1.0 Mpa and LHSV=0.6 h−1. The heat treatment temperature determined the crystallinity of TiOSO4 and specific surface area of these catalysts, which affected the catalytic performance of these catalysts in 1-butene oligomerization. In addition, the physicochemical properties of these catalysts were comparatively characterized by powder X-ray diffraction (XRD), N2 isothermal adsorption-desorption techniques.


2010 ◽  
Vol 93-94 ◽  
pp. 22-26 ◽  
Author(s):  
Surachai Artkla ◽  
Won Yong Choi ◽  
Jatuporn Wittayakun

This work compared properties and catalytic performance of two hybrid photocatalysts, TiO2/RH-MCM-41 and TiO2/TEOS-MCM-41 prepared by loading nanoparticles of TiO2 (10 wt.%) on MCM-41 synthesized with rice husk silica and tetraethyl orthosilicate respectively. The supports and catalysts were characterized by X-ray diffraction, N2 adsorption-desorption, transmission electron microscopy and zeta potential. The photocatalytic activities of the TiO2/RH-MCM-41 and TiO2/TEOS-MCM-41 for the degradation of tetramethylammonium (TMA) in aqueous slurry were similar with a complete conversion after irradiation time of 90 min at pH 7.


2020 ◽  
Vol 4 (4) ◽  
pp. 1-3
Author(s):  
Liu L

The mesoporous ZSM-5 zeolite containing MoCoP/Al2O3 catalyst (C12-ZSM5) with the mixture of Al2O3 and mesoporous ZSM- 5 zeolite as carrier was synthesized. The catalytic performance of C12-ZSM5 catalyst was evaluated by the hydrodesulfurization (HDS) of different diesel feedstock. The carriers and catalysts were characterized by N2 adsorption-desorption, pyridine-FTIR, X-ray diffraction (XRD) and CO in-situ FTIR (CO-FTIR) techniques. Results showed that mesoporous ZSM-5 can improve the acidity of the catalyst and increase the number of MoCoS active phases. The C12-ZSM5 catalyst had low HDS and HDN activity, because the acidic sites of mesoporous ZSM-5 were easily occupied by nitrogen compounds. The HDS activity of C12-ZSM5 catalyst was fully exploited by using graded packing technology, the sulfur content of product oil was 5.9 ng/μL. The relative HDS activity of C12-ZSM5 catalyst is 1.47 times that of FHUDS-8 catalyst.


2021 ◽  
Vol 21 (12) ◽  
pp. 6082-6087
Author(s):  
Chih-Wei Tang ◽  
Hsiang-Yu Shih ◽  
Ruei-Ci Wu ◽  
Chih-Chia Wang ◽  
Chen-Bin Wang

The increase of harmful carbon monoxide (CO) caused by incomplete combustion can affect human health even lead to suffocation. Therefore reducing the CO discharged by vehicles or factories is urgent to improve the air quality. The spinel cobalt (II, III) oxide (Co3O4) is an active catalyst for CO abatement. In this study, we tried to fabricate dispersing Co3O4 via the dispersion-precipitation method with acetic acid, formic acid, and oxalic acid as the chelating dispersants. Then, the asprepared samples were calcined at 300 ºC for 4 h to obtain active catalysts, and assigned as Co(A), Co(F) and Co(O) respectively, the amount of the dispersants used are labeled as I (0.12 mole), II (0.03 mole) and III (0.01 mole). For comparison, another CoAP sample was prepared via alkaliinduced precipitation and calcined at 300 ºC. All samples were characterized by X-ray diffraction (XRD), temperature-programmed reduction (TPR), scanning electron microscope (SEM), and nitrogen adsorption/desorption system, and the catalytic activity focused on the CO oxidation. The influence of chelating dispersant on the performance of abatement of CO was pursued in this study. Apparently, the results showed that the chelating dispersant can influence the catalytic activity of CO abatement. An optimized ratio of dispersant can improve the performance, while excess dispersant lessens the surface area and catalytic performance. The series of Co(O) samples can easily donate the active oxygen since the labile Co–O bonding and indicated the preferential performance than both Co(A) and Co(F) samples. The nanorod Co(O)-II showed preferential for CO oxidation, T50 and T90 approached 96 and 127 ºC, respectively. Also, the favorable durability of Co(O)-II sample maintains 95% conversion still for 50 h at 130 ºC and does not emerge deactivation.


2021 ◽  
Vol 16 (1) ◽  
pp. 88-96
Author(s):  
Mukhamad Nurhadi ◽  
Ratna Kusumawardani ◽  
Teguh Wirawan ◽  
Sumari Sumari ◽  
Sin Yuan Lai ◽  
...  

The catalytic performance of titania-supported carbon mesoporous-derived from fish bones (TiO2/CFB) has been investigated in styrene oxidation with aqueous H2O2. The preparation steps of (TiO2/CFB) catalyst involved the carbonization of fish bones powder at 500 °C for 2 h. followed by impregnation of titania using titanium(IV) isopropoxide (500 µmol) precursor, and calcined at 350 °C for 3 h. The physical properties of the adsorbents were characterized using Fourier transform infrared, X-ray diffraction (XRD), Scanning electron microscopy with energy dispersive X-ray (SEM-EDX), and nitrogen adsorption-desorption studies. The catalytic test was carried out using styrene oxidation with H2O2 as an oxidant at room temperature for 24 h. Its catalytic activity was compared with Fe2O3/CFB, CuO/CFB, TiO2, and CFB catalysts. It is demonstrated that the catalytic activity of TiO2/CFB catalyst has the highest compared to Fe2O3/CFB, CuO/CFB, TiO2, and CFB catalysts in the oxidation of styrene with styrene conversion ~23% and benzaldehyde selectivity ~90%. Kinetics of TiO2/CFB catalyzed oxidation of styrene has been investigated and mechanism for oxidation of styrene has been proposed. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA   License (https://creativecommons.org/licenses/by-sa/4.0). 


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Manh B. Nguyen ◽  
Giang H. Le ◽  
Trang T. T. Pham ◽  
Giang T. T. Pham ◽  
Trang T. T. Quan ◽  
...  

Catalytic ozonation is a new method used for removal of NH4OH solution. Therefore, high catalytic performance (activity and selectivity) should be achieved. In this work, we report the synthesis and catalytic performance of Fe2O3-Co3O4 modified dolomite in the catalytic ozonation of NH4OH solution. Dolomite was successfully activated and modified with Fe2O3 and Co3O4. Firstly, dolomite was activated by heating at 800°C for 3 h and followed by KOH treatment. Activated dolomite was modified with Fe2O3 by the atomic implantation method using FeCl3 as Fe source. Fe2O3 modified dolomite was further modified with Co3O4 by precipitation method. The obtained catalysts were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), N2 adsorption–desorption (BET), and temperature-programmed reduction (H2-TPR). From SEM image, it was revealed that nano-Fe2O3 and Co3O4 particles with the size of 80–120 nm. Catalytic performance of activated dolomite, Fe2O3 modified dolomite, and Fe2O3-Co3O4 modified dolomite in catalytic ozonation of NH4+ solution was investigated and evaluated. Among 3 tested catalysts, Fe2O3-Co3O4 modified dolomite has the highest NH4+ conversion (96%) and N2 selectivity (77.82%). Selectivity toward N2 over the catalyst was explained on the basis of bond strength M-O in oxides through the standard enthalpy ΔH°f of oxide. Catalyst with lower ΔH°f value has higher N2 selectivity and the order is the following: Co3O4 (ΔH°f of 60 kcal (mole O)) > Fe2O3 (ΔH°f of 70 kcal (mole O)) > MgO (ΔH°f of 170 kcal (mole O)). Moreover, high reduction ability of Fe2O3-Co3O4 modified dolomite could improve the N2 selectivity by the reduction of NO3- to N2 gas.


Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 710
Author(s):  
Linmeng Huo ◽  
Tian Wang ◽  
Keng Xuan ◽  
Lei Li ◽  
Yanfeng Pu ◽  
...  

The adsorption and activation of both CO2 and methanol are mainly affected by the distance of the Lewis acid site, Zr4+, and Lewis base, Zr4+/O2−, of the Zr-based catalysts. In this paper, Zr-incorporated SBA-15 (Zr-SBA-15) and Zr-grafted SBA-15 (Zr/SBA-15) catalysts were prepared with different Zr environments, and were analyzed with N2 adsorption–desorption isotherms, X-ray diffraction, UV-vis spectra, and XPS. It was proposed that Zr-SBA-15 catalyst with Si-O-Zr-OH and Zr-O-Si-OH structure exhibited non-adjacent sites between Zr4+ and Zr4+/O2−, while Zr/SBA-15 catalyst with Zr-O-Zr-OH structure showed neighboring sites between Zr4+ and Zr4+/O2−. Furthermore, the Zr/SBA-15 catalyst exhibited good catalytic activity, while no DMC was detected over the Zr-SBA-15 catalyst at the same reaction conditions. For combined in situ infrared and catalytic performance, it was indicated that the methanol and CO2 could be activated to form DMC, only when the Zr4+ and Zr4+/O2− sites existed and were adjacent to each other in the Zr-O-Zr-OH of Zr/SBA-15 catalyst.


2012 ◽  
Vol 465 ◽  
pp. 224-228 ◽  
Author(s):  
Hong Qi Guo ◽  
Gong Yan ◽  
Ming Qing Chen ◽  
Shi Rong Liu

12-tungstophosphoric acid was supported on amine-modified SBA-15 by impregnation. The structure and properties of the catalyst were characterized by FT-IR spectroscopy, X-ray diffraction, N2 adsorption-desorption, TEM,Raman spectra and NH3–TPD technology.the result confirmed the mesostructure for SBA-15 and the Keggin structure of the heteropolyanions was preserved. The tungstophosphoric acid can disperse in the pore of the support SBA-15/NH2, but the acidity of the catalyst reduced. The catalytic activities of the catalysts were evaluated for the esterification reaction of ethyl acetoacetate and ethylene glycol .and the catalysts supported on amine-modified SBA-15 show excellent reusability and selectivity.


2013 ◽  
Vol 67 (4) ◽  
Author(s):  
Ya-Ping Zhang ◽  
Ke-Chuang Xue ◽  
Wei-Ping Zhang ◽  
Chao Song ◽  
Rong-Lan Zhang ◽  
...  

AbstractA series of tetracarboxylphthalocyanines (MPc(COOH)4, M = H, Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II)) were anchored onto MCM-41 by the following procedures: functionalization of MCM-41 with (EtO)3SiCH2CH2CH2NH2 reacting with surface Si-OH, and anchoring MPc(COOH)4 onto MCM-41 with a substitution reaction between chloroformyl and amino groups. The samples were characterized by infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, N2 adsorption-desorption, and X-ray photoelectron spectroscopy. Catalytic activity of oxidation was tested using solutions of ethanethiol in petroleum ether and thiophene in octane; CoPc-CONH-MCM-41 displayed the highest conversion ratio of 90.15 % and 93.79 %, respectively.


2019 ◽  
Vol 44 (1) ◽  
pp. 29-36
Author(s):  
Hua Song ◽  
Xueya Dai ◽  
Nan Jiang ◽  
Zijin Yan ◽  
Tianhan Zhu ◽  
...  

Neodymium (Nd)- or yttrium (Y)- modified bulk Ni2P catalysts (Nd-Ni2P or Y-Ni2P) have been successfully prepared and their catalytic performance in benzofuran hydrodeoxygenation have been investigated. The as-prepared catalysts were characterised by X-ray diffraction, N2 adsorption–desorption, CO uptake and X-ray photoelectron spectroscopy. The addition of Nd or Y, especially Nd, can increase the surface area of the catalysts and promote the formation of smaller and more highly dispersed Ni2P particles. The Nd-Ni2P catalyst showed the highest benzofuran hydrodeoxygenation activity of 95.3% and the O-free products yield of 74.6%, which gives an increase of 25.3% and 35.4% when compared with that found for Ni2P.


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