scholarly journals Improving the Catalytic Performance of Keggin [PW12O40]3− for Oxidative Desulfurization: Ionic Liquids versus SBA-15 Composite

Materials ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1196 ◽  
Author(s):  
Susana Ribeiro ◽  
Beatriz Duarte ◽  
Baltazar de Castro ◽  
Carlos Granadeiro ◽  
Salete Balula
Keyword(s):  
High Performance ◽  
Oxidative Desulfurization ◽  
Catalytic Performance ◽  
The Novel ◽  
Operational Conditions ◽  
Waste Production ◽  
Acid Proton ◽  
Desulfurization Efficiency ◽  
Model Diesel ◽  
Multicomponent Model

Different methodologies were used to increase the oxidative desulfurization efficiency of the Keggin phosphotungstate [PW12O40]3− (PW12). One possibility was to replace the acid proton by three different ionic liquid cations, forming the novel hybrid polyoxometalates: [BMIM]3PW12 (BMIM as 1-butyl-3-methylimidazolium), [BPy]3PW12 (BPy as 1-butylpyridinium) and [HDPy]3PW12 (HDPy as hexadecylpyridinium. These hybrid Keggin compounds showed high oxidative desulfurization efficiency in the presence of [BMIM]PF6 solvent, achieving complete desulfurization of multicomponent model diesel (2000 ppm of S) after only 1 h, using a low excess of oxidant (H2O2/S = 8) at 70 °C. However, their stability and activity showed some weakness in continuous reused oxidative desulfurization cycles. An improvement of stability in continuous reused cycles was reached by the immobilization of the Keggin polyanion in a strategic positively-charged functionalized-SBA-15 support. The PW12@TM–SBA-15 composite (TM is the trimethylammonium functional group) presented similar oxidative desulfurization efficiency to the homogeneous IL–PW12 compounds, having the advantage of a high recycling capability in continuous cycles, increasing its activity from the first to the consecutive cycles. Therefore, the oxidative desulfurization system catalyzed by the Keggin-type composite has high performance under sustainable operational conditions, avoids waste production during recycling and allows catalyst recovery.

scholarly journals Solvent-Free Desulfurization System to Produce Low-Sulfur Diesel Using Hybrid Monovacant Keggin-Type Catalyst

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 4961
Author(s):  
Fátima Mirante ◽  
Baltazar de Castro ◽  
Carlos M. Granadeiro ◽  
Salete S. Balula
Keyword(s):  
Oxidative Desulfurization ◽  
Catalytic Efficiency ◽  
Catalytic Performance ◽  
Sulfur Compounds ◽  
Solvent Free ◽  
Clean Diesel ◽  
Liquid Liquid Extraction ◽  
Model Diesel ◽  
Low Sulfur ◽  
Multicomponent Model

Two quaternary ammonium catalysts based on the monovacant polyoxotungstate ([PW11O39]7−, abbreviated as PW11) were prepared and characterized. The desulfurization performances of the PW11-based hybrids (of tetrabutylammonium and trimethyloctadecylammonium, abbreviated as TBA[PW11] and ODA[PW11], respectively), the corresponding potassium salt (K7PW11O39, abbreviated as KPW11) and the peroxo-compound (TBA-PO4[WO(O2)2], abbreviated as TBA[PW4]) were compared as catalysts for the oxidative desulfurization of a multicomponent model diesel (2000 ppm S). The oxidative desulfurization studies (ODS) were performed using solvent-free systems and aqueous H2O2 as oxidant. The nature of the cation in the PW11 catalyst showed to have an important influence on the catalytic performance. In fact, the PW11-hybrid catalysts showed higher catalytic efficiency than the peroxo-compound TBA[PW4], known as Venturello compound. TBA[PW11] revealed a remarkable desulfurization performance with 96.5% of sulfur compounds removed in the first 130 min. The reusability and stability of the catalyst were also investigated for ten consecutive ODS cycles without loss of activity. A treated clean diesel could be recovered without sulfur compounds by performing a final liquid/liquid extraction diesel/EtOH:H2O mixture (1:1) after the catalytic oxidative step.

Oxidative desulfurization catalyzed by a novel ZrP/MCM-41 catalyst with high performance

2020 ◽  
Vol 4 (8) ◽  
pp. 4293-4300
Author(s):  
Panpan Zhang ◽  
Lihua Kang ◽  
Mingyuan Zhu ◽  
Bin Dai
Keyword(s):  
High Performance ◽  
Oxidative Desulfurization ◽  
Catalytic Performance ◽  
Excellent Catalytic Performance ◽  
Mcm 41

The excellent catalytic performance of the ZrP/MCM-41 catalyst in oxidative desulfurization was attributed to the Zr–OH sites.

scholarly journals An Effective Hybrid Heterogeneous Catalyst to Desulfurize Diesel: Peroxotungstate@Metal–Organic Framework

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5494
Author(s):  
Yan Gao ◽  
Fátima Mirante ◽  
Baltazar de Castro ◽  
Jianshe Zhao ◽  
Luís Cunha-Silva ◽  
...  
Keyword(s):  
Heterogeneous Catalyst ◽  
Metal Organic Framework ◽  
Oxidative Desulfurization ◽  
Catalytic Efficiency ◽  
Catalytic Performance ◽  
Impregnation Method ◽  
Extraction Solvent ◽  
Metal Organic ◽  
Model Diesel ◽  
Organic Framework

A peroxotungstate composite comprising the chromium terephthalate metal–organic framework MIL-101(Cr) and the Venturello peroxotungstate [PO4{WO(O2)2}4]3− (PW4) has been prepared by the impregnation method. The PW4@MIL-101(Cr) composite presents high catalytic efficiency for oxidative desulfurization of a multicomponent model diesel containing the most refractory sulfur compounds present in real fuels (2000 ppm of total S). The catalytic performance of this heterogeneous catalyst is similar to the corresponding homogeneous PW4 active center. Desulfurization efficiency of 99.7% was achieved after only 40 min at 70 °C using H2O2 as an oxidant and an ionic liquid as an extraction solvent ([BMIM]PF6, 2:1 model diesel/[BMIM]PF6). High recycling and reusing capacity was also found for PW4@MIL-101(Cr), maintaining its activity for consecutive oxidative desulfurization cycles. A comparison of the catalytic performance of this peroxotungstate composite with others previously reported tungstate@MIL-101(Cr) catalysts indicates that the presence of active oxygen atoms from the peroxo groups promotes a higher oxidative catalytic efficiency in a shorter reaction time.

A Fuel Cell Stack Architecture to Make all Cells Have Equal Operational Conditions and Performance

2012 ◽  
Author(s):  
Hong Liu ◽  
Peiwen Li ◽  
Alexandra Hartz
Keyword(s):  
Fuel Cell ◽  
High Performance ◽  
Proton Exchange Membrane ◽  
Experimental Tests ◽  
Proton Exchange ◽  
The Novel ◽  
Fuel Cell Stack ◽  
Operational Conditions ◽  
And Performance ◽  
Exchange Membrane

This paper presents a novel architecture for a proton-exchange membrane (PEM) fuel cell stack, which is based on the concept that every cell in the stack works at the same condition and thus each cell has the same contribution to the overall output voltage and power. To meet this proposed requirement, special flow distributors were used to evenly distribute fuel and airflow to every fuel cell in the stack. Details of the flow distributor and experimental tests of a four-cell fuel cell stack are presented in the paper. The experimental results demonstrated the desired high performance of the fuel cell stack. It is proved that the novel architecture for fuel cell stack is successful and of significance to the development of high performance fuel cell stacks.

scholarly journals Ultra-Deep Oxidative Desulfurization of Fuel with H2O2 Catalyzed by Mesoporous Silica-Supported Molybdenum Oxide Modified by Ce

2021 ◽  
Vol 11 (5) ◽  
pp. 2018
Author(s):  
Yang Chen ◽  
Qi Tian ◽  
Yongsheng Tian ◽  
Jiawei Cui ◽  
Guanghui Wang
Keyword(s):  
Mesoporous Silica ◽  
Molybdenum Oxide ◽  
Photoelectron Spectroscopy ◽  
Oxidative Desulfurization ◽  
Catalytic Performance ◽  
Fuel Oil ◽  
Reaction Products ◽  
X Ray ◽  
Operational Conditions ◽  
Apparent Activation Energies

A mesoporous silica-supported molybdenum oxide catalyst with a cerium(Ce) modifier was prepared by in situ synthesis and used in a hydrogen peroxide (H2O2) system for the desulfurization of dibenzothiophene (DBT), benzothiophene (BT), and 4,6-dimethyldibenzothiophene (4,6-DMDBT) fuel oils. The catalytic performance of the catalyst was studied. The catalyst was characterized by Fourier Transform Infra-Red(FT-IR), X-ray diffraction (XRD), Brunner−Emmet−Teller (BET), and X-ray Photoelectron Spectroscopy(XPS). The influences of m(catalyst)/m(fuel oil), v(H2O2)/v(fuel oil), reaction temperature, and reaction time were investigated. The catalyst had excellent catalytic oxidation desulfurization performance under moderate operational conditions. The catalytic performance was in the order DBT > 4,6-DMDBT > BT. The kinetic analysis results showed that the reaction was a pseudo first-order kinetics process and the apparent activation energies of DBT, BT, and 4,6-DMDBT were 46.67 kJ/mol, 56.23 kJ/mol, and 55.54 kJ/mol, respectively. The reaction products of DBT, BT, and 4,6-DMDBT were DBTO2, BTO2, and 4,6-DMDBTO2, respectively. The recycling experiments indicated that DBT, BT, and 4,6-DMDBT removal could still reach levels of 94.0%, 63.0%, and 77.9% after five cycles.

scholarly journals Influence of UiO-66(Zr) Preparation Strategies in Its Catalytic Efficiency for Desulfurization Process

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3009 ◽  
Author(s):  
Alexandre M. Viana ◽  
Susana O. Ribeiro ◽  
Baltazar de Castro ◽  
Salete S. Balula ◽  
Luís Cunha-Silva
Keyword(s):  
Reaction Time ◽  
Metal Organic Framework ◽  
Oxidative Desulfurization ◽  
Catalytic Efficiency ◽  
Porous Metal ◽  
Catalytic Performance ◽  
Cooling Time ◽  
High Catalytic Activity ◽  
Desulfurization Process ◽  
Desulfurization Efficiency

Porous metal-organic framework (MOF) materials UiO-66(Zr) obtained by solvothermal and microwave advanced synthesis (MWAS) procedures were characterized, and their catalytic efficiency was investigated for oxidative desulfurization (ODS) processes using a multicomponent model diesel containing benzothiophene and dibenzothiophene derivatives. The preparation parameters as the cooling time after oven use in the solvothermal procedure, and also the reaction time in the MWAS method seemed to play an important role in the catalytic performance of the UiO-66(Zr) material, as well as in its recycle capacity. The material prepared by the solvothermal procedure with a fast cooling time showed the best catalytic performance (desulfurization efficiency of 99.5% after 3 h). However, the application of the UiO-66(Zr) material prepared by the MWAS method (desulfurization efficiency of 96% after 3 h) conciliated a higher number of advantages, such as shorter reaction time preparation (15 min) and high catalytic activity for a higher number of reaction cycles. The UiO-66(Zr) prepared by the MWAS method was used for the first time in an oxidative desulfurization process, and according to the catalytic results obtained (high recycle capacity and stability) and shorter reaction time preparation, seems to be a promising material for industrial application.

scholarly journals Pocket MUSE: an affordable, versatile and high-performance fluorescence microscope using a smartphone

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yehe Liu ◽  
Andrew M. Rollins ◽  
Richard M. Levenson ◽  
Farzad Fereidouni ◽  
Michael W. Jenkins
Keyword(s):  
High Performance ◽  
Point Of Care ◽  
Low Cost ◽  
Consumer Electronics ◽  
Practical Implementation ◽  
The Novel ◽  
Point Of Care Diagnostics ◽  
Optical Module ◽  
Optical Configuration ◽  
User Friendly

AbstractSmartphone microscopes can be useful tools for a broad range of imaging applications. This manuscript demonstrates the first practical implementation of Microscopy with Ultraviolet Surface Excitation (MUSE) in a compact smartphone microscope called Pocket MUSE, resulting in a remarkably effective design. Fabricated with parts from consumer electronics that are readily available at low cost, the small optical module attaches directly over the rear lens in a smartphone. It enables high-quality multichannel fluorescence microscopy with submicron resolution over a 10× equivalent field of view. In addition to the novel optical configuration, Pocket MUSE is compatible with a series of simple, portable, and user-friendly sample preparation strategies that can be directly implemented for various microscopy applications for point-of-care diagnostics, at-home health monitoring, plant biology, STEM education, environmental studies, etc.

scholarly journals Plunging Airfoil: Reynolds Number and Angle of Attack Effects

Aerospace ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 216
Author(s):  
Emanuel A. R. Camacho ◽  
Fernando M. S. P. Neves ◽  
André R. R. Silva ◽  
Jorge M. M. Barata
Keyword(s):  
Reynolds Number ◽  
High Performance ◽  
Angle Of Attack ◽  
Systems Design ◽  
Reynolds Numbers ◽  
Navier Stokes ◽  
Low Reynolds Numbers ◽  
Operational Conditions ◽  
Naca0012 Airfoil ◽  
The Mean

Natural flight has consistently been the wellspring of many creative minds, yet recreating the propulsive systems of natural flyers is quite hard and challenging. Regarding propulsive systems design, biomimetics offers a wide variety of solutions that can be applied at low Reynolds numbers, achieving high performance and maneuverability systems. The main goal of the current work is to computationally investigate the thrust-power intricacies while operating at different Reynolds numbers, reduced frequencies, nondimensional amplitudes, and mean angles of attack of the oscillatory motion of a NACA0012 airfoil. Simulations are performed utilizing a RANS (Reynolds Averaged Navier-Stokes) approach for a Reynolds number between 8.5×103 and 3.4×104, reduced frequencies within 1 and 5, and Strouhal numbers from 0.1 to 0.4. The influence of the mean angle-of-attack is also studied in the range of 0∘ to 10∘. The outcomes show ideal operational conditions for the diverse Reynolds numbers, and results regarding thrust-power correlations and the influence of the mean angle-of-attack on the aerodynamic coefficients and the propulsive efficiency are widely explored.

Extraction Coupled with Aerobic Oxidative Desulfurization of Model Diesel Using a B-type Anderson Polyoxometalate Catalyst in Ionic Liquids

2019 ◽  
Vol 149 (7) ◽  
pp. 1888-1893 ◽  
Author(s):  
Lulu Sun ◽  
Ting Su ◽  
Pengcheng Li ◽  
Jiajia Xu ◽  
Naimeng Chen ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Oxidative Desulfurization ◽  
Model Diesel

In situ growth of ultrathin Ni–Fe LDH nanosheets for high performance oxygen evolution reaction

2017 ◽  
Vol 4 (7) ◽  
pp. 1173-1181 ◽  
Author(s):  
Haidong Yang ◽  
Sha Luo ◽  
Yun Bao ◽  
Yutong Luo ◽  
Jun Jin ◽  
...  
Keyword(s):  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
High Performance ◽  
Copper Foil ◽  
Catalytic Performance ◽  
In Situ Growth ◽  
Ultrathin Nanosheet

The ultrathin Ni70Fe30LDH nanosheets were successfullyin situgrown on anodic polarized copper foil, denoted as u-Ni70Fe30LDHs/a-CF. Benefiting from the ultrathin nanosheet structure, the catalyst exhibits remarkable catalytic performance for OER in 1 M KOH solution.

Sign in / Sign up

Export Citation Format

Share Document