scholarly journals Hydrodesulfurization of 4,6-Dimethyldibenzothiophene and the Diesel Oil Fraction on NiMo Catalysts Supported over Proton-Exchanged AlMCM-41 and TiMCM-41 Extrudates

Catalysts ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1086
Author(s):  
Karolina Jaroszewska ◽  
Marek Lewandowski ◽  
Kinga Góra-Marek ◽  
Jolanta Grzechowiak ◽  
Gérald Djéga-Mariadassou
Keyword(s):  
Catalytic Efficiency ◽  
Active Phase ◽  
Order Rate Constant ◽  
Diesel Oil ◽  
High Dispersion ◽  
Catalytic Systems ◽  
Oil Fraction ◽  
Metal Support Interaction ◽  
Nimo Catalysts ◽  
Mcm 41

NiMo catalysts supported on mesoporous MCM-41 type materials shaped with binder were tested for activity in the hydrodesulfurization of 4,6-dimethyldibenzothiophene (4,6-DMDBT) and the diesel fuel fraction (0.92 wt% of sulfur). The aim of the investigation was to evaluate the effect of ion exchange with protons of Al- or Ti-substituted MCM-41 mesoporous supports. The subjected catalytic systems were NiMo/HAlMCM-41 and NiMo/HTiMCM-41, and for comparison purposes NiMo/AlMCM-41 and NiMo/TiMCM-41. The samples were characterized by N2 sorption (at 77 K), XRD, TEM, XPS, SEM and Py–IR. It was found that the functionalization of AlMCM-41 and TiMCM-41 with protons increased the conversion of 4,6-DMDBT and the pseudo-first-order rate constant. Correspondingly, 4,6-DMDBT HDS reactions over the NiMo/HTiMCM-41 catalyst proceeded to a similar extent via hydrogenation and direct desulfurization, whereas over the NiMo/HAlMCM-41 they proceeded mainly via direct desulfurization. Furthermore, the ion-exchanged catalysts displayed two-fold higher efficiency in direct desulfurization than their non-modified counterparts. The NiMo/HTiMCM-41 catalyst exhibited the highest catalytic efficiency in the HDS of 4,6-DMDBT and the diesel oil fraction. The high activity of the NiMo/HTiMCM-41 catalyst is mainly attributed to its appropriate acidity, as well as the metal–support interaction providing both the high dispersion of the active phase and the desirable multilayered stacking morphology of the active phase slabs.

Effect of Titania Grafting on Behavior of NiMo HDS Catalysts Supported on Nanostructured Silica Materials

2012 ◽  
Vol 1371 ◽  
Author(s):  
A. Mendoza-Nieto ◽  
I. Puente-Lee ◽  
C. Salcedo-Luna ◽  
T. Klimova
Keyword(s):  
Total Pore Volume ◽  
Bet Surface Area ◽  
Silica Supports ◽  
Metal Support Interaction ◽  
Silica Materials ◽  
Hds Catalysts ◽  
Metal Support ◽  
Nimo Catalysts ◽  
Nanostructured Silica ◽  
Mcm 41

ABSTRACTIn the present work, a comparison study of the NiMo hydrodesulfurization (HDS) catalysts supported on different nanostructured supports of MCM-41 and SBA-15-types and the same ones modified by TiO2 grafting was undertaken. The aim of this study was to inquire on the effect of the characteristics of the primary silica supports on the activity and selectivity of the NiMo catalysts modified with titania in deep HDS. Supports and catalysts were characterized by nitrogen physisorption, small-angle and powder XRD, TPR, UV-vis DRS, and HRTEM, and tested in the simultaneous HDS of dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT). It was found that titania grafting on all silica supports resulted in a slight decrease of BET surface area and total pore volume. However, the characteristic p6mm hexagonal pore arrangement of the used nanostructured silica materials was not affected. Powder X-ray diffraction pointed out a good dispersion of Mo and Ni oxide species in all prepared catalysts. TPR characterization of the NiMo catalysts revealed some increase in the metal-support interaction after titania grafting on the silica surface. Further DRS characterization indicated that the best dispersion of Mo oxide species was obtained on the TiSBA-15 support. Titania addition to the silica supports also produced an increase in the dispersion of the sulfided NiMo phase, which was more marked for SBA-15 support than for the MCM-41 (HRTEM). The most active NiMo/Ti-SBA-15 catalyst resulted to be significantly more active (∼40 %) than the conventional NiMo/γ-Al2O3 catalyst in HDS of 4,6-DMDBT.

Nickel (II) and oxovanadium (IV) complexes supported on MCM-41 mesoporous and their application in catalytic selective sulfide and thiol oxidation

2020 ◽  
Vol 23 ◽  
Author(s):  
Mohsen Nikoorazm ◽  
Maryam Khanmoradi ◽  
Masoumeh Sayadian
Keyword(s):  
Catalytic Activity ◽  
Room Temperature ◽  
Sol Gel ◽  
Reaction Times ◽  
Significant Loss ◽  
Spectral Studies ◽  
High Catalytic Activity ◽  
Catalytic Systems ◽  
Solvent Free Conditions ◽  
Mcm 41

Introduction:: MCM-41 was synthesized using the sol-gel method. Then two new transition metal complexes of Nickel (II) and Vanadium (IV), were synthesized by immobilization of adenine (6-aminopurine) into MCM-41 mesoporous. The compounds have been characterized by XRD, TGA, SEM, AAS and FT-IR spectral studies. Using these catalysts provided an efficient and enantioselective procedure for oxidation of sulfides to sulfoxides and oxidative coupling of thiols to their corresponding disulfides using hydrogen peroxide at room temperature. Materials and Methods:: To a solution of sulfide or thiol (1 mmol) and H2O2 (5 mmol), a determined amount of the catalyst was added. The reaction mixture was stirred at room temperature for the specific time under solvent free conditions. The progress of the reaction was monitored by TLC using n-hexane: acetone (8:2). Afterwards, the catalyst was removed from the reaction mixture by centrifugation and, then, washed with dichloromethane in order to give the pure products. Results:: All the products were obtained in excellent yields and short reaction times indicating the high activity of the synthesized catalysts. Besides, the catalysts can be recovered and reused for several runs without significant loss in their catalytic activity. Conclusion:: These catalytic systems furnish the products very quickly with excellent yields and VO-6AP-MCM-41 shows high catalytic activity compared to Ni-6AP-MCM-41.

scholarly journals Tailoring of Hydrotalcite-Derived Cu-Based Catalysts for CO2 Hydrogenation to Methanol

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1058 ◽  
Author(s):  
Leone Frusteri ◽  
Catia Cannilla ◽  
Serena Todaro ◽  
Francesco Frusteri ◽  
Giuseppe Bonura
Keyword(s):  
Metallic Copper ◽  
Chemical Properties ◽  
Active Phase ◽  
Co2 Hydrogenation ◽  
High Dispersion ◽  
Experimental Conditions ◽  
Typical Structure ◽  
Methanol Production ◽  
Physico Chemical ◽  
Space Time Yield

Ternary CuxZnyAlz catalysts were prepared using the hydrotalcite (HT) method. The influence of the atomic x:y:z ratio on the physico-chemical and catalytic properties under CO2 hydrogenation conditions was probed. The characterization data of the investigated catalysts were obtained by XRF, XRD, BET, TPR, CO2-TPD, N2O chemisorption, SEM, and TEM techniques. In the “dried” catalyst, the typical structure of a hydrotalcite phase was observed. Although the calcination and subsequent reduction treatments determined a clear loss of the hydrotalcite structure, the pristine phase addressed the achievement of peculiar physico-chemical properties, also affecting the catalytic activity. Textural and surface effects induced by the zinc concentration conferred a very interesting catalyst performance, with a methanol space time yield (STY) higher than that of commercial systems operated under the same experimental conditions. The peculiar behavior of the hydrotalcite-like samples was related to a high dispersion of the active phase, with metallic copper sites homogeneously distributed among the oxide species, thereby ensuring a suitable activation of H2 and CO2 reactants for a superior methanol production.

Tuning the metal–support interaction in supported K-promoted NiMo catalysts for enhanced selectivity and productivity towards higher alcohols in CO hydrogenation

2017 ◽  
Vol 7 (18) ◽  
pp. 4206-4215 ◽  
Author(s):  
Jiaxi Yong ◽  
Xuebin Luan ◽  
Xiaoping Dai ◽  
Xin Zhang ◽  
Hongyan Qiao ◽  
...  
Keyword(s):  
Co Hydrogenation ◽  
Higher Alcohols ◽  
Support Interaction ◽  
Metal Support Interaction ◽  
Metal Support ◽  
Nimo Catalysts ◽  
Enhanced Selectivity

Ni–KMoS/MMO catalysts were obtained using encapsulated Mo-based precursors to tune metal–support interaction, and enhanced selectivity and productivity towards higher alcohols.

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.

Trimetallic Sulfide Catalysts for Hydrodesulfurization

2016 ◽  
pp. 240-262 ◽  
Author(s):  
Rafael Huirache-Acuña ◽  
Gabriel Alonso-Nuñez ◽  
Eric M. Rivera-Muñoz ◽  
Omar Gutierrez ◽  
Barbara Pawelec
Keyword(s):  
Active Phase ◽  
Diesel Oil ◽  
Catalyst Preparation ◽  
Refining Industry ◽  
Sulfide Catalysts ◽  
Hydrotreating Catalysts ◽  
Ternary Sulfide ◽  
The World ◽  
And Performance ◽  
State Of Art

The more stringent environmental regulations enacted throughout the world have increased the need of more active hydrotreating (HDT) catalysts, in the petroleum refining industry. Usually, the catalysts used for diesel oil hydrotreatment are ?-Al2O3 supported molybdenum or tungsten sulfides promoted with cobalt or nickel. Current strategies for the design of novel HDS catalysts often include variations in the support formulation, catalyst preparation method and active phase formulation. In this sense, the new generations of catalysts, such as NEBULA®, are based on a totally different concept of bulk-like. In this chapter, we present recent research related to the synthesis, characterization and performance of trimetallic sulfide nanocatalysts for hydrodesulfurization. The present chapter analyses the state of art of the ternary sulfide hydrotreating catalysts.

scholarly journals Functionalized Ordered Mesoporous Silicas (MCM-41): Synthesis and Applications in Catalysis

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 617 ◽  
Author(s):  
Gabriel Martínez-Edo ◽  
Alba Balmori ◽  
Iris Pontón ◽  
Andrea Martí del Rio ◽  
David Sánchez-García
Keyword(s):  
Mesoporous Silica ◽  
Pore Structure ◽  
Metallic Nanoparticles ◽  
Mesoporous Silicas ◽  
Acid Catalysts ◽  
Catalytic Systems ◽  
Research Attention ◽  
Ordered Mesoporous ◽  
Regioselective Functionalization ◽  
Mcm 41

Mesoporous silica sieves are among the most studied nano-objects due to their stable pore structure and easy preparation. In particular, MCM-41 have attracted increasing research attention due to their chemical versatility. This review focuses on the synthesis and regioselective functionalization of MCM-41 to prepare catalytic systems. The topics covered are: mono and di-functionalized MCM-41 as basic and acid catalysts, catalysts based on metallic complexes and heteropolyacids supported onto MCM-41, metallic nanoparticles embed onto functionalized MCM-41 and magnetic MCM-41 for catalytic purposes.

scholarly journals Can we measure catalyst efficiency in asymmetric chemical reactions? A theoretical approach

2009 ◽  
Vol 5 ◽  
Author(s):  
Shaimaa El-Fayyoumy ◽  
Matthew H Todd ◽  
Christopher J Richards
Keyword(s):  
Chemical Reactions ◽  
Small Molecule ◽  
Enantiomeric Excess ◽  
Catalytic Efficiency ◽  
Catalytic Systems ◽  
Asymmetric Catalysts ◽  
Asymmetric Catalytic ◽  
Short Period ◽  
Asymmetric Catalyst ◽  
Catalyst Efficiency

Small molecule asymmetric catalysts are often described as being “good” or “bad” but to date there has been no way of comparing catalyst efficiency quantitatively. We define a simple formula, Asymmetric Catalyst Efficiency (ACE), that allows for such a comparison. We propose that a catalyst is more efficient if fewer atoms are utilised to give a product in a required enantiomeric excess. We illustrate this concept by analysing several well-known asymmetric catalytic chemical reactions carried out in academic laboratories, and compare small molecule catalysts with enzymes. We conclude that ACE is a useful descriptor for the comparison of diverse catalytic systems. It is also noteworthy that, despite the relatively short period of investigation into small molecule catalysts, they are competitive with enzymes with regards to this measure of catalytic efficiency.

scholarly journals In Situ Generated Nanosized Sulfide Ni-W Catalysts Based on Zeolite for the Hydrocracking of the Pyrolysis Fuel Oil into the BTX Fraction

Catalysts ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1152
Author(s):  
Tatiana Kuchinskaya ◽  
Mariia Kniazeva ◽  
Vadim Samoilov ◽  
Anton Maximov
Keyword(s):  
Photoelectron Spectroscopy ◽  
Active Phase ◽  
Fuel Oil ◽  
Oil Fraction ◽  
Transmission Electron ◽  
Catalytically Active ◽  
Pyrolysis Fuel Oil ◽  
Benzene Toluene ◽  
Catalytic Reactivity

The hydrocracking reaction of a pyrolysis fuel oil fraction using in situ generated nano-sized NiWS-sulfide catalysts is studied. The obtained catalysts were defined using X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The features of catalytically active phase generation, as well as its structure and morphology were considered. The catalytic reactivity of in situ generated catalysts was evaluated using the hydrocracking reaction of pyrolysis fuel oil to obtain a light fraction to be used as a feedstock for benzene, toluene, and xylene (BTX) production. It was demonstrated that the temperature of 380 °C, pressure of 5 MPa, and catalyst-to-feedstock ratio of 4% provide for a target fraction (IPB −180 °C) yield of 44 wt %, and the BTX yield of reaching 15 wt %.

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