Nanostructured SBA-15 Materials as Appropriate Supports for Active Hydrodesulfurization Catalysts Prepared from HSiW Heteropolyacid

2012 ◽  
Vol 1479 ◽  
pp. 77-82 ◽  
Author(s):  
J.A. Mendoza-Nieto ◽  
K.D. Tejeda-Espinosa ◽  
I. Puente-Lee ◽  
C. Salcedo-Luna ◽  
T. Klimova
Keyword(s):  
Active Phase ◽  
Catalytic Performance ◽  
Nominal Composition ◽  
Incipient Wetness Impregnation ◽  
Model Compounds ◽  
Characteristic Structure ◽  
Pure Silica ◽  
Sulfided Catalysts ◽  
Phase Precursor ◽  
Deep Hydrodesulfurization

ABSTRACTA series of NiW catalysts supported on SBA-15-type materials modified with Al, Ti or Zr were prepared and tested in simultaneous hydrodesulfurization (HDS) of two model compounds: dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT). Catalysts were prepared by incipient wetness impregnation of SBA-type materials (pure silica SBA-15, Al-SBA-15, Ti-SBA-15 or Zr-SBA-15) using Keggin-type heteropolyacid H4SiW12O40 as active phase precursor and nickel nitrate. Nominal composition of the catalysts was 19 wt.% of WO3 and 3 wt.% of NiO. The supports and catalysts were characterized by SEM-EDX, N2physisorption, small-angle and powder XRD, UV-Vis DRS, TPR and HRTEM. It was shown that a good dispersion of Al, Ti and Zr species on the SBA-15 surface was reached. The characteristic structure of the SBA-15 support was preserved in all supports and NiW catalysts. Addition of metal atoms (Al, Ti, Zr) on the SBA-15 surface prior to catalysts’ preparation improved dispersion of Ni and W oxide species in calcined catalysts. HRTEM characterization of sulfided catalysts showed that the dispersion of NiW active phase was also better on metal-containing SBA-15 supports than on the pure silica one. All NiW catalysts supported on metal-containing SBA-15 materials showed an outstanding catalytic performance in HDS of both model compounds used (DBT and 4,6-DMDBT). A good correlation was found between the dispersion of sulfided NiW active phase and catalytic activity results. The highest HDS activity was obtained with the NiW catalyst supported on Zr-containing SBA-15 molecular sieve, which makes it a promising catalytic system for ultra-deep hydrodesulfurization of diesel fuel.

Tuning the catalytic performance of Co/Mg-La system for ammonia synthesis via the active phase precursor introduction method

2020 ◽  
Vol 598 ◽  
pp. 117553 ◽  
Author(s):  
Hubert Ronduda ◽  
Magdalena Zybert ◽  
Wojciech Patkowski ◽  
Aleksandra Tarka ◽  
Przemysław Jodłowski ◽  
...  
Keyword(s):  
Ammonia Synthesis ◽  
Active Phase ◽  
Catalytic Performance ◽  
Phase Precursor

Self-hydrogen transfer hydrogenolysis of β-O-4 linkages in lignin catalyzed by MIL-100(Fe) supported Pd–Ni BMNPs

2017 ◽  
Vol 19 (19) ◽  
pp. 4538-4543 ◽  
Author(s):  
Jia-wei Zhang ◽  
Guo-ping Lu ◽  
Chun Cai
Keyword(s):  
Hydrogen Transfer ◽  
Catalytic Performance ◽  
Model Compounds ◽  
Lignin Model Compounds ◽  
Organosolv Lignin ◽  
Lignin Model ◽  
Intramolecular Transfer ◽  
Supported Pd

A MIL-100(Fe) supported Pd–Ni BMNP catalyst has been fabricated, and the catalyst exhibits superior catalytic performance toward intramolecular transfer hydrogenolysis of lignin model compounds and organosolv lignin.

Trimetallic RuxMoNi Catalysts Supported on SBA-15 for the Hydrodesulfurization of Dibenzothiophene

2018 ◽  
Vol 17 (5) ◽  
Author(s):  
N.L. Torres-García ◽  
R. Huirache-Acuña ◽  
T.A. Zepeda-Partida ◽  
B. Pawelec ◽  
J.L.G. Fierro ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Catalytic Activity ◽  
Chelating Agent ◽  
Active Phase ◽  
Atomic Ratio ◽  
Support Interaction ◽  
Micro Raman Spectroscopy ◽  
Metal Support Interaction ◽  
Sulfided Catalysts ◽  
Metal Support

Abstract In this work, novel trimetallic catalysts based on transition metal sulphides (Ru, Mo and Ni) supported on SBA-15 were synthesized. Citric acid (CA) was used as chelating agent in order to enhance the dispersion of the active phase and minimize the metal-support interaction. Sulfided catalysts were evaluated in the reaction of hydrodesulfurization (HDS) of dibenzothiophene (DBT) at 320 °C and 54.5 atm of total H2 pressure. The effects of different Ru/(Ni + Mo) atomic ratios on the active phase were studied. The catalysts were characterized using Micro-Raman spectroscopy, DRIFTS, XRD, XPS, HR-TEM and SEM techniques. Results have shown that there was a better dispersion of the metallic phases, which improves the physicochemical properties of the catalysts, increasing the catalytic activity. The trimetallic RuxMoNi catalyst with the lowest atomic ratio, have shown superior catalytic activity compared to their higher atomic ratio counterparts. The interaction of the chelating agent improved the catalytic activity, which was superior to that observed for NiMo based catalysts, considered one of the most active hydrotreating catalysts.

scholarly journals CO-PROX Reaction over Co3O4|Al2O3 Catalysts—Impact of the Spinel Active Phase Faceting on the Catalytic Performance

2019 ◽  
Vol 123 (33) ◽  
pp. 20221-20232 ◽  
Author(s):  
Gabriela Grzybek ◽  
Klaudia Ciura ◽  
Joanna Gryboś ◽  
Paulina Indyka ◽  
Arantxa Davó-Quiñonero ◽  
...  
Keyword(s):  
Active Phase ◽  
Catalytic Performance

scholarly journals Preparation and Characterization of Cu-Mn-Ce@γ-Al2O3 to Catalyze Ozonation in Coal Chemical Wastewater-Biotreated Effluent

2019 ◽  
Vol 16 (8) ◽  
pp. 1439
Author(s):  
Yue Teng ◽  
Ke Yao ◽  
Wenbin Song ◽  
Yongjun Sun ◽  
Haoliang Liu ◽  
...  
Keyword(s):  
Reaction Time ◽  
Calcination Temperature ◽  
Catalytic Performance ◽  
Catalytic Ozonation ◽  
Operating Conditions ◽  
Operating Parameters ◽  
Incipient Wetness Impregnation ◽  
X Ray Diffraction ◽  
Calcination Time ◽  
Catalyst Dosage

Cu-Mn-Ce@γ-Al2O3 was prepared by incipient wetness impregnation and used to catalyze ozonation in a coal chemical wastewater-biotreated effluent. The preparation factors that considerably affected the catalytic performance of Cu-Mn-Ce@γ-Al2O3, specifically metal oxide loading percentage, calcination temperature, and calcination time, were examined. The catalyst was characterized by scanning electron microscopy, energy dispersive spectrometry, X-ray diffraction, and Brunauer-Emmett-Teller analysis. The optimal catalytic ozonation operating parameters, such as ozone dosage, catalyst dosage, pH, and reaction time, were also investigated. Results showed that an optimized catalyst consisted of 17.0% CuO, 3.0% MnO2, and 2.0% CeO2 (wt.%). The optimal calcination temperature and calcination time were 600 °C and 5 h. The optimal catalytic ozonation operating parameters, including ozone dosage, catalyst dosage, pH, and reaction time, were 7, 80.0 mg/L, 20.0 mg/L, 7 and 50 min, respectively. The COD removal of biotreated effluent increased to 61% under these optimal operating conditions. Meanwhile, ozonation alone resulted in only 20% removal. This work proposes the use of easily available Cu-Mn-Ce@γ-Al2O3 catalyst and might drive the advancement of catalytic ozonation for chemical wastewater purification.

scholarly journals Highly Active Trifloaluminate Ionic Liquids as Recyclable Catalysts for Green Oxidation of 2,3,6-Trimethylphenol to Trimethyl-1,4-Benzoquinone

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1469
Author(s):  
Piotr Latos ◽  
Agnieszka Siewniak ◽  
Natalia Barteczko ◽  
Sebastian Jurczyk ◽  
Sławomir Boncel ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Ionic Liquids ◽  
High Selectivity ◽  
Active Phase ◽  
Catalytic Performance ◽  
Reaction Parameters ◽  
Multiwalled Carbon ◽  
Highly Active ◽  
Recyclable Catalysts ◽  
Fold Excess

An effective method for the synthesis of 2,3,6-trimethyl-1,4-benzoquinone via the oxidation of 2,3,6-trimethylphenol as the key step in the in the preparation of vitamin E was presented. An aqueous solution of H2O2 was used as the oxidant and Lewis acidic trifloaluminate ionic liquids [emim][OTf]-Al(OTf)3, χAl(OTf)3 = 0.25 or 0.15 as catalysts. Trifloaluminate ionic liquids were synthesised by the simple reaction between 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (triflate) [emim][OTf] and aluminium triflate used in sub-stoichiometric quantities. The influence of the reaction parameters on the reaction course, such as the amount and concentration of the oxidant, the amount of catalyst, the amount and the type of organic solvent, temperature, and the reaction time was investigated. Finally, 2,3,6-trimethyl-1,4-benzoquinone was obtained in high selectivity (99%) and high 2,3,6-trimethylphenol conversion (84%) at 70 °C after 2 h of oxidation using a 4-fold excess of 60% aqueous H2O2 and acetic acid as the solvent. The catalytic performance of trifloaluminate ionic liquids supported on multiwalled carbon nanotubes (loading of active phase: 9.1 wt.%) was also demonstrated. The heterogeneous ionic liquids not only retained their activity compared to the homogenous counterparts, but also proved to be a highly recyclable catalysts.

Effect of silver on the catalytic hydrodechlorination of tetrachloromethane over silica-supported palladium-silver catalysts

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Magdalena Bonarowska ◽  
Zbigniew Kaszkur ◽  
Zbigniew Karpiński
Keyword(s):  
Gas Phase ◽  
Palladium Catalysts ◽  
Catalytic Performance ◽  
Incipient Wetness Impregnation ◽  
Significant Extent ◽  
Silver Addition ◽  
Catalytic Hydrodechlorination ◽  
Silver Catalysts ◽  
Supported Palladium ◽  
Incipient Wetness

AbstractTwo silica-supported palladium based catalysts characterized by overall metal loadings 10 wt.%, and atomic Pd : Ag ratios of 100 : 0 and 70 : 30, were prepared by incipient wetness impregnation, subjected to reduction in hydrogen and characterized by XRD. It was found that incipient wetness co-impregnation of silica resulted in the formation of a catalyst characterized by relatively small metal crystallites (~11 nm) and significant extent of Pd-Ag alloying. The catalytic performance was investigated in the hydrodechlorination of tetrachloromethane in the gas phase. Silver addition to palladium in the co-impregnated catalysts had very pronounced effect, vastly decreasing the overall activity (conversion) and also the selectivity towards hydrocarbons, propensity characteristic for the monometallic palladium catalysts working in CCl4 hydrodechlorination carried out in the gas phase. Instead, large amounts of C2HxCly dimeric products were formed. These dimers are considered as possible coke precursors. Post-reaction samples of both catalysts contained large amount of carbon which entered the Pd and Pd-Ag phases. This carbon can be easily removed by treatment with hydrogen at 450ºC.

Activity of yFe-10Cu/H-Sep and xCu/H-Sep for the Selective Catalytic Reduction of NO with Propylene

2012 ◽  
Vol 518-523 ◽  
pp. 281-284
Author(s):  
Qing Ye ◽  
Hai Ping Wang ◽  
Hai Xia Zhao ◽  
Shui Yuan Cheng ◽  
Tian Fang Kang
Keyword(s):  
Catalytic Reduction ◽  
Catalytic Performance ◽  
High Dispersion ◽  
High Catalytic Activity ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Promotional Effect ◽  
Scr Of No ◽  
Metal Support Interaction ◽  
Metal Support

Cu supported on acid-treated sepiolite catalysts (xCu/H-Sep, x = 0  20.0 wt%) or Cu-Fe mixed supported on acid-treated sepiolite catalysts (yFe-10Cu/H-Sep, y = 0  20.0 wt%) were prepared by the incipient wetness impregnation method. The xCu/H-Sep and yFe-10Cu/H-Sep catalysts were characterized by means of XRD, BET, XRF, XPS, and H2-TPR techniques, and their catalytic activities were evaluated for the SCR of NO with propylene. XPS and XRD results indicate that there was the co-presence of Cu+-Cu2+ and Fe2+-Fe3+ over the surfaces of yFe-10Cu/H-Sep catalysts, and there was a strong interaction between Cu, Fe and sepiolite. High promotional effect of iron additive on the catalytic performance of Cu/H-Sep catalyst were found in C3H6-SCR of NO reaction. The highest activity of 65% NO conversion was obtained over 15Fe-10Cu/H-Sep catalyst at 280 oC under the condition of 1000 ppm NO, 1000 ppm C3H6, and 5% O2. The high catalytic activity of 15Fe-10Cu/H-Sep catalyst for NO reduction was due to its high reducibility to activate C3H6 to selectively reduce NO in the presence of excess O2. The high dispersion of copper oxides and strong metal-support interaction over 15Fe-10Cu/H-Sep catalyst also improve its catalytic performance.

Preparation of TiO2-Al2O3 Support and Hydrodenitrogenation over Ni2P/TiO2-Al2O3 Catalyst

2014 ◽  
Vol 881-883 ◽  
pp. 245-250
Author(s):  
Jing Sen Yan ◽  
Hai Yan Wang ◽  
Feng Wei He
Keyword(s):  
Reduction Method ◽  
Bond Cleavage ◽  
Great Influence ◽  
Active Phase ◽  
Molar Ratio ◽  
Incipient Wetness Impregnation ◽  
Aluminium Nitrate ◽  
Titanium Sulfate ◽  
Co Precipitation

A series of TiO2-Al2O3 composite supports were prepared by co-precipitation of titanium sulfate and aluminium nitrate , and the nickel phosphide catalysts were prepared by incipient wetness impregnation and in situ H2 reduction method. The catalysts were characterized by XRD, N2 adsorption, TPR, TEM and XPS techniques. Their hydrodenitrogenation (HDN) performances were evaluated by using quinoline as model molecules . The results show that TiO2 was evenly dispersed on massive γ-Al2O3 surface. The introduction of TiO2 weakened the strong interaction between Al2O3 and phosphate, and improved the reducibility of the precursors , facilitating to the formation of Ni2P active phase. TiO2 acted as an electronic promoter for the Ni-P catalyst and enhanced both the hydrogenation and C-N bond cleavage activities. Different Ti / Al molar ratio had great influence on HDN activity of the catalyst. The Ni2P /TiO2-Al2O3 with Ti/Al ratio of 1/8, exhibited the highest activity for quinoline HDN.

scholarly journals Effect of Preparation Mode on the Properties of Mn-Na-W/SiO2 Catalysts for Oxidative Coupling of Methane: Conventional Methods vs. POSS Nanotechnology

2016 ◽  
Vol 18 (2) ◽  
pp. 93 ◽  
Author(s):  
I.Z. Ismagilov ◽  
E.V. Matus ◽  
V.V. Kuznetsov ◽  
M.A. Kerzhentsev ◽  
S.A. Yashnik ◽  
...  
Keyword(s):  
Catalytic Performance ◽  
Oxidative Coupling Of Methane ◽  
Molar Ratio ◽  
High Dispersion ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Preparation Mode ◽  
Slurry Method ◽  
Conventional Methods

<p>Reflectance spectroscopic methods the electronic, redox and structural properties of Mn-Na-W/SiO<sub>2</sub> catalysts prepared by the incipient wetness impregnation method and mixture slurry method were studied in detail. Since POSS nanotechnology (POSS = polyhedral oligomeric silsesquioxanes) has attracted attention as tooling for synthesis of catalysts with novel properties and functionalities, we expanded this method for the preparation of Mn-Na-W/SiO<sub>2</sub> catalyst. The physicochemical and catalytic properties of Mn-Na-W/SiO<sub>2</sub> catalysts prepared by conventional methods and POSS nanotechnology were examined comparatively. In all studied Mn-Na-W/SiO<sub>2</sub> catalysts both individual oxides (MnO<sub>x</sub>, WO<sub>3</sub>) and bimetal oxide phases (Na<sub>2</sub>WO<sub>4</sub>, MnWO<sub>4</sub>) are found in addition to oxide particles of high dispersion. The UV-Vis Diffuse Reflectance indicates that Na<sup>+</sup> cations facilitates stabilization of octahedrally coordinated Mn<sup>3+</sup><sub>Oh</sub> cations in the isolated state, while Mn<sup>3+</sup><sub>Oh</sub> promote the disordering of W<sup>6+</sup> cations in the supported system. The Mn-Na-W/SiO<sub>2</sub> prepared using metal-POSS precursors marks out presence of unglobular SiO<sub>2</sub> particles, higher dispersion of MnO<sub>x</sub> and MnWO<sub>4</sub> particles and more easily reducible metal-oxide species. The catalysts prepared by incipient impregnation method and mixture slurry method have practically similar catalytic performance while the catalyst prepared by POSS nanotechnology method shows lower activity and selectivity. At 800‒850 °C the increase of C<sub>2</sub> hydrocarbons yield from 4 to 15% and the rise of molar ratio С<sub>2</sub>Н<sub>4</sub>/C<sub>2</sub>H<sub>6</sub> from 0.2 to 1 are observed when impregnation or mixture slurry method are used for catalyst preparation instead of POSS nanotechnology method.</p>

Sign in / Sign up

Export Citation Format

Share Document