Hydrodesulfurization Reaction Research Articles

Direct Evidence of the Role of Co or Pt, Co Single-Atom Promoters on the Performance of MoS2 Nanoclusters for the Hydrogen Evolution Reaction

Developing alternatives to platinum (Pt) and iridium (Ir) in proton-exchange membrane water electrolyzers is crucial on the way to viable energy provision schemes. However, although it seems difficult to substitute Ir, alternatives exist for Pt at the proton-exchange membrane water electrolyzer cathode. Here, we report on the synthesis and the characterization of efficient and durable hydrogen evolution reaction (HER) nanocatalysts based on MoS2 supported on high-surface-area carbon. Citric acid was used as a chelating agent to control the size of the MoS2 crystallites (1.4 nm) and thus the density of active sites (slab edges). Inspired by successful approaches in catalysis for hydrodesulfurization reactions, conventional 2H MoS2 was sequentially doped with cobalt (Co) and then with 1 wt % of Pt. Overpotentials of 188, 140, and 118 mV at 10 mA cm–2 are reported for MoS2/C, Co–MoS2/C, and Pt1%–CoMoS2/C, respectively. This result is attributed to the weakening of the Hads binding energy of the promoted MoS2-edge active sites (because the promoting atoms are mostly located at the edges). Associated with small-metal dissolution rates (monitored in situ, during the HER), our findings demonstrate that metal promotion (doping) is a promising route to replace Pt with earth-abundant elements in acidic water electrolyzers.

Enhanced activity of Co–Mo–S catalysts towards hydrodesulfurization and hydrogen evolution reaction via NaBH4 assisted formation

NaBH4 modification was developed for efficient Co–MoS catalysts, which can produce more high-activity 1T phase and better catalytic activity for both the HER and HDS.

Recent advances in defect-engineered molybdenum sulfides for catalytic applications.

Electrochemical energy conversion and storage driven by renewable energy sources is drawing ever-increasing interest owing to the needs of sustainable development. Progress in the related electrochemical reactions relies on highly active and cost-effective catalysts to accelerate the sluggish kinetics. A substantial number of catalysts have been exploited recently, thanks to the advances in materials science and engineering. In particular, molybdenum sulfide (MoSx) furnishes a classic platform for studying catalytic mechanisms, improving catalytic performance and developing novel catalytic reactions. Herein, the recent theoretical and experimental progress of defective MoSx for catalytic applications is reviewed. This article begins with a brief description of the structure and basic catalytic applications of MoS2. The employment of defective two-dimensional and non-two-dimensional MoSx catalysts in the hydrogen evolution reaction (HER) is then reviewed, with a focus on the combination of theoretical and experimental tools for the rational design of defects and understanding of the reaction mechanisms. Afterward, the applications of defective MoSx as catalysts for the N2 reduction reaction, the CO2 reduction reaction, metal-sulfur batteries, metal-oxygen/air batteries, and the industrial hydrodesulfurization reaction are discussed, with a special emphasis on the synergy of multiple defects in achieving performance breakthroughs. Finally, the perspectives on the challenges and opportunities of defective MoSx for catalysis are presented.

On Stability of High-Surface-Area Al2O3, TiO2, SiO2-Al2O3, and Activated Carbon Supports during Preparation of NiMo Sulfide Catalysts for Parallel Deoxygenation of Octanoic Acid and Hydrodesulfurization of 1-Benzothiophene

NiMo sulfide catalysts were prepared by the impregnation of high surface area supports with an aqueous solution made of NiCO3·2Ni(OH)2, MoO3 and citric acid, followed by freeze drying and sulfidation in H2S/H2 mixture. N2 physisorption and X-ray diffraction were selected to investigate the amphoteric oxides Al2O3 and TiO2, acidic SiO2-Al2O3 and activated carbon supports, fresh prepared sulfide NiMo catalysts and spent catalysts after model parallel reaction of octanoic acid deoxygenation and 1-benzothiophene hydrodesulfurization. The studied mesoporous amphoteric oxides Al2O3 and TiO2 did not lead to highly active NiMo catalysts due to the low hydrothermal stability of these supports during the preparation of the active sulfide phase and deoxygenation reaction. The most active catalyst based on oxidic support was the NiMo sulfide supported on acidic mesoporous SiO2-Al2O3, which was explained by the increased stability of this support to the water and CO/CO2 mixture during the activation of the sulfidic phase and deoxygenation reaction. The extraordinarily high stability of the activated carbon support led to outstanding activities of the sulfidic NiMo/C catalyst.

NiMo/C-HY catalyst prepared from doping zeolite slurry in a superabsorbent polymer for DBT and 4,6-DMDBT hydrodesulfurization

This study utilized the swelling properties of superabsorbent polymers (SAP) to adsorb zeolite sols and slurries to construct C-HY composites. The synthesized C-HY composites proved to be effective supports for NiMo catalysts in the hydrodesulfurization (HDS) of dibenzothiophene (DBT) and 4,6-dimethyl-dibenzothiophene (4,6-DMDBT). XRD, BET, SEM, TG, NH3-TPD, FTIR, H2-TPR, TEM and XPS were used to characterization the texutural structure, acidity and metal distribution of prepared NiMo/C-HY catalysts. By combining zeolite slurries with SAPs, HY can be efficiently incorporated into carbon substrate structure in three dimensions (3D), thereby changing the structural characteristics, morphology, acidity, and metal distribution of HDS catalysts. The conversion of DBT decreases sequentially: NiMo/C-HY-s > NiMo/C-HY-h > NiMo/C-HY-p > NiMo/C-HY-c, and the conversion of 4,6-DMDBT decreased sequentially: NiMo/C-HY-s > NiMo/C-HY-p > NiMo/C-HY-h ≫ NiMo/C-HY-c. The introduction of HY into the carbon support can increase the HDS reaction rate of NiMo/C by more than 1.2–1.5 times. The intrinsic reaction activity of NiMo/C-HY-s can even exceed that of traditional NiMo/Al2O3 catalysts. Based on the same Mo loading amount, the HDS activity of NiMo/C-HY-s is twice that of NiMo/Al2O3 in DBT HDS and 1.1–1.5 times that of NiMo/Al2O3 in 4,6-DMDBT HDS. It is thought that HY in carbon composites promotes C–S bond cleavage of sulfur-containing molecules in DBT HDS. The unique dispersion of Mo species induced by HY favors the formation of highly stacked NiMoS active phases, which may be the crucial in 4,6-DMDBT HDS.

Aluminium‐Catalyzed Selective Reduction of Heteroallenes Through Hydroboration: Amide/Thioamide/Selenoamide Bond Construction and C=X (X=O, S, Se) Bond Activation**

AbstractAn unprecedented conjugated bis‐guanidinate (CBG) stabilized aluminium dihydride, [LAlH2; (L={(ArNH)(ArN)−C=N−C=(NAr)(NHAr)}; Ar=2,6‐Et2‐C6H3)] (I) catalyzed chemoselective hydroboration of heteroallenes such as carbodiimide (CDI)s, isocyanates, isothiocyanates, and isoselenocyanates is reported. A wide range of heteroallenes, including electron‐donating and withdrawing groups, experience hydroboration to obtain selectively N‐boryl amide, N‐borylaminal, and N‐boryl methyl amine products. More importantly, a single sustainable molecular aluminium‐based catalyst effectively catalyzes CDIs, isocyanates, isothiocyanates, and isoselenocyanates into formamidines, formamides, thioformamides, and selenoformamides, respectively. Further, heteroallene substrates undergo hydrodeoxygenation (HDO), hydrodesulfurization (HDS), and hydrodeselenization (HDSe) reactions leading to N‐boryl methyl amines. In addition, a series of control and kinetic experiments indicate that the aluminium hydride species are essential for all partial and complete reduction steps and breaking the C=X (X=O, S, and Se) bonds in heteroallenes.

Hydrodesulfurization over NiMo Catalysts Supported on Yolk‐shell Silica Materials with Controllable Cavity Size

AbstractNovel yolk‐shell (YS) mesoporous silica materials with different cavity sizes were successfully synthesized. Aluminium was bridged into the yolk‐shell framework of silica by a post synthesis method to improve the acidity of YS, namely Al‐YS. The corresponding NiMo/Al‐YS catalysts were also fabricated and used in the hydrodesulfurization (HDS) reaction of dibenzothiophene (DBT) and 4,6‐dimethyldibenzothiophene (4,6‐DMDBT). The NiMo/Al‐YS catalyst with the cavity size of 154 nm (NiMo/Al‐YS‐154) exhibits the superior conversions of DBT (99.2 %) and 4,6‐DMDBT (96.1 %) at 340 °C, 4.0 MPa, 10 h−1, highest kHDS (13.4×10−4 mol g−1 h−1 for DBT and 8.9 mol g−1 h−1 for 4,6‐DMDBT) and highest TOF for DBT (3.7 h−1) and 4,6‐DMDBT (2.3 h−1) among the investigated catalysts. The appropriate cavity size of NiMo/Al‐YS‐154 catalyst plays the key role in obtaining its superior HDS catalytic performance. Furthermore, the possible reaction networks of DBT and 4, 6‐DMDBT HDS over NiMo/Al‐YS‐x catalysts were also presented.

Reaction laws of polycyclic aromatic hydrocarbons and heteroatomic compounds in hydrocracking process

Based on the Structure Oriented Lumping (SOL) method, a molecular-level reaction kinetic model for hydrocracking process was established to investigate the reaction laws of polycyclic aromatic hydrocarbons (PAHs) and heteroatomic compounds in hydrocracking process and calculate the molecular compositions of hydrocracking products. Molecules showed different reaction laws due to the differences of the initial contents, the structural increments and their positions in the reaction network. Since the hydrodenitrogenation reactions of indole and carbazole homologs were more difficult to carry out than the hydrodesulfurization reactions of benzothiophene and dibenzothiophene homologues, the denitrification rate was lower than the desulphurization rate at the outlet of the hydrotreating section. When the reaction temperature of the hydrotreating section was 360 °C, the conversion rates of sulfides and nitrides were 98.4 % and 91.3 %, respectively. The increase of reaction temperature intensified the hydrogenation saturation of aromatics, the ring opening of naphthenes and the cracking of paraffins. As the reaction temperature of the hydrocracking section rose from 370 °C to 410 °C, more isomerized carbon ions were generated due to the β-position cracking of paraffins. The mass ratio of methylbutane to n-pentane in light naphtha increased from 1.29 to 3.08. The increase of reaction temperature accelerated the side chain cracking reactions of naphthenes with 4 or more carbon atoms in the side chains, and generates more naphthenes with 0 to 3 carbon atoms in the side chains. Aromatics mainly underwent the ring-by-ring hydrogenation saturation reactions in the hydrotreating section, and bicyclic aromatic hydrocarbons was significantly easier to be hydrogenated than monocyclic aromatic hydrocarbons.

Hydrodesulfurization of Dibenzothiophene over Ni-Mo-W Sulfide Catalysts Supported on Sol-Gel Al2O3-CeO2.

To achieve sulfur content in gas oil at a near-zero level, new catalysts with improved hydrogenation functions are needed. In this work, new Ni-Mo-Mo hydrodesulfurization (HDS) catalysts supported by Al2O3-CeO2 materials were synthesized to evaluate their efficiency in the reaction of HDS with dibenzothiophene (DBT). Al2O3-CeO2 supports different CeO2 loadings (0, 5, 10 and 15 wt.%) and supported NiMoW catalysts were synthesized by sol-gel and impregnation methods, respectively. The physicochemical properties of the supports and catalysts were determined by a variety of techniques (chemical analysis, XRD, N2 physisorption, DRS UV-Vis, XPS, and HRTEM). In the DBT HDS reaction carried out in a batch reactor at 320 °C and a H2 pressure of 5.5 MPa, the sulfide catalysts showed a dramatic increase in activity with increasing CeO2 content in the support. Nearly complete DBT conversion (97%) and enhanced hydrogenation function (HYD) were achieved on the catalyst with the highest CeO2 loading. The improved DBT conversion and selectivity towards the hydrogenation products (HYD/DDS ratio = 1.6) of this catalyst were attributed to the combination of the following causes: (i) the positive effect of CeO2 in forcing the formation of the onion-shaped Mo(W)S2 layers with a large number of active phases, (ii) the inhibition of the formation of the undesired NiAlO4 spinel phase, (iii) the appropriate textural properties, (iv) the additional ability for heterolytic dissociation of H2 on the CeO2 surfaces, and (v) the increase in Brønsted acidity.

Effects of Al introduction methods for Al-SBA-15 on NiMoS active phase morphology and hydrodesulfurization reaction selectivities

A series of Al-SBA-15 were synthesized with three Al introduction methods and different Si/Al molar ratios. The introduction methods included the direct synthesis (DS), post-synthesis grafting (PG) and impregnation synthesis (IM) method. The Si/Al molar ratios of Al-SBA-15 materials were 20, 10 and 5 respectively. The corresponding NiMoS catalysts were performed by hydrodesulfurization (HDS) recations of dibenzothiophene (DBT) to analyze reaction behavior. The characterization results of N2-physisorption, X-ray diffraction and 27Al NMR presented that the Al introduction method has a direct effect on the physical and chemical properties of Al-SBA-15. PG method could introduce most of Al atoms into the framework of parent- material, which was opposed to the IM method. The DS method could better maintain the pore structure advantages of the Al-SBA-15. The PG-NiMo catalyst had the strongest metal-support interaction, and the NiMoS slabs presented the lowest average stacking number over this catalyst. The reaction results showed that DS-NiMo catalyst obtained the highest HDS activity, and PG-NiMo catalyst presented the highest HDS hydrogenolysis selectivity of DBT. It is speculated that the frame-work Al has strong metal interaction with metal oxide precursor, and the morphology of NiMoS Phase has important effect on the selectivity of DBT HDS.

Unraveling the Structure and Surface Chemistry of the Phosphosulfide Phase Formed on Ni2P under Hydrodesulfurization Reaction Conditions: A DFT Study

There is experimental evidence that the actual active phase of the Ni2P catalyst under hydrodesulfurization (HDS) reaction conditions is a nickel phosphosulfide phase formed on the catalyst surface. Combining DFT calculations and an atomistic thermodynamic approach, we investigated the possibility of sulfur adsorption as well as the replacement of surface phosphorus by sulfur on the (0001) and (1010) surfaces of the Ni2P catalyst. Our DFT calculations showed that sulfur could replace up to 100% of the surface phosphorus under hydrodesulfurization (HDS) reaction conditions. We identify that possible sulfur adsorption sites on both surface terminations are arrangements of Ni trimers (Ni3 sites). We found that only the phosphosulfide phase formed on the (1010)-AB_Ni2P surface termination has coordinatively unsaturated Ni atoms available for the adsorption of organic sulfur-containing compounds. Our results suggest that the phosphosulfide phase formed on the (1010)-AB_Ni2P termination and not on the (0001)-Ni3P2 termination could be responsible for the high HDS activity of the Ni2P catalyst. Upon the replacement of P by S, the Ni3 sites undergo tensile strain, and their reactivity toward S adsorption is modified by the imposed strain. We found that the Ni–Ni bond distance is an important parameter in describing the HDS activity of the Ni2P catalyst. By analyzing the relationship among the ensemble, ligand, and strain effects, we were able to provide a better understanding of the promoting effect introduced by the formation of the nickel phosphosulfide phase.

Understanding the effects of feedstock blending and catalyst support on hydrotreatment of algae HTL biocrude with non-edible vegetable oil

The performance of cobalt-molybdenum (CoMo) on hydrotreating of algae HTL biocrude and carinata oil was investigated. Commercial CoMo/Al2O3 (CoMo/Al) and synthesized CoMo supported on Douglas fir biochar (CoMo/DF), sulfided or unsulfided catalysts, were compared for hydrodeoxygenation (HDO), hydrodenitrogenation (HDN), hydrodesulfurization (HDS) and hydrodemetallization (HDM) reactions. Results showed that there lies a synergistic effect when HTL algae biocrude and carinata oil blends are hydrotreated. The yield of the upgraded blend (UB) oils retrieved over alumina catalyst was higher than the individual hydrotreated parent oils. For example, a 9% and 5% increase in yield was noted compared to the average of individual hydrotreated parent oils. The UB produced from sulfided CoMo/Al exhibited superior HDO activity primarily by decarbonylation. This was apparent in increased heating value, carbon addition, higher octane number, and lower total acid number than the oils obtained from the biochar-supported catalysts. Sulfided CoMo/DF catalyzed cracking reactions which lowered the viscosity, followed by high HDN and HDS activity compared to the commercial catalyst. The two supports showed different sorption behaviors. Interestingly, CoMo/DF had an effective sorption mechanism that helped in higher metal removal from the oil. Additionally, presulfiding and DF support exhibited positive results in term of less coke formation. In brief, biochar supports have higher acidic sites, inorganic mineral oxides, ion exchange capacity, high surface area, pore structure and connectivity. All of these make a substantial contribution to its unique catalytic behavior.

V-Containing Heteropoly Acids with Keggin Structure as Precursors of Sulfide Catalysts: Regularities of the Convertion of Dibenzothiophene and Naphthalene on Nonpromoted Mo–V Catalysts

Mixed PMoV heteropoly acids with Keggin structures H3+xPMo12–xVxO40 (x = 1–6) and modified sulfide catalysts on their basis were synthesized, their physicochemical characteristics were determined, and their performance in the reactions of hydrodesulfurization (HDS) of dibenzothiophene (DBT) and hydrogenation of naphthalene was evaluated. Modification of the Mo-containing catalysts with vanadium by impregnation with a solution of mixed heteropoly acids was found to enhance their catalytic activity in the studied reactions, as well as to increase the selectivity for the direct hydrodesulfurization route of the DBT HDS reaction.

Effects of temperature and time on the facile low-temperature pre-sulfurization of tube-like unsupported Co-Mo catalysts for hydrodesulfurization

A Co-Mo sulfide catalyst with tube-like structure was prepared through a low-temperature pre-sulfurization process using rod-like CoMoO4 as the precursor. The pre-sulfurization temperature greatly affected the total pore volume, the concentration of CoMoS species, the microstructure of (Co)MoS2 slabs and the catalytic desulfurization activity. The increased temperature can promote the formation of hollow structure and the sulfurization degree of the precursor. It was found that the excessive temperature induced the Co atoms to form more isolated Co9S8 species, hindering the formation of highly active CoMoS species. Therefore, appropriate temperature is more favorable to form the (Co)MoS2 slabs with shorter length and higher stacking number, leading to more coordinatively unsaturated sites, especially the corner sites. According to the results of hydrodesulfurization reaction, the reaction rate of dibenzothiophene and the yields of liquid products are highly depended on the number of surface-active sites, which are mainly originated from the Type II CoMoS species. Moreover, the extended pre-sulfurization time can further improve the catalytic desulfurization activity of the catalyst at an appropriate pre-sulfurization temperature.

Elucidating the mechanisms of titanium–induced morphological and structural changes in catalysts on mesoporous Al2O3–TiOx mixed oxides: Effect of non–stoichiometric TiOx phase

In the present work, mesoporous Al 2 O 3 –TiO x composites with different titania loadings (4, 8 and 12 wt%) were synthesized to evaluate the effect of non-stoichiometric TiO x phases on the hydrodesulfurization (HDS) ability of the CoMo/Al 2 O 3 –TiO x catalysts. The activity of the catalysts was evaluated in the dibenzothiophene (DBT) HDS reaction carried out at 593 K, 5.5 MPa in a batch reactor. Regardless of the TiO x content, all sulfided CoMo Al 2 O 3 –TiO x catalysts were more active than the CoMo/Al 2 O 3 catalyst. For all catalysts, DBT HDS occurs mainly through the direct desulfurization (DDS) pathway (95–97% selectivity). The most active catalysts (CoMo-12 and CoMo-4) showed evidence of the presence of non-stoichiometric titanium oxides. The synthesized materials were characterized in depth to evaluate their crystallinity, textural and morphological properties, elemental composition and acidity. Their characterization showed that: (i), the Al 2 O 3 –TiO x interaction increased with decreasing TiO x content; (ii) the strong interaction between TiO x particles and alumina led to the formation of more defined TiO x structures; (iii), an increase in titania content led to the growth of TiO x crystals along the [101] direction (relative to the [001] direction), which in turn, led to the different TiO x morphologies: nanorods → nanotubes → U-shaped nanotubes. The TiCoMoS phase can be formed if the process is performed on Ti 3 O 5 instead of TiO 2 . • Titania loading influenced on the metal–support interaction and the type of titania phases. • Ti–promoted species are related to increase of the direct desulfurization route. • Non–stoichiometric titanium oxides are necessary to formation of TiCoMoS active phase.

Hydrodesulfurization of 4,6–Dimethyldibenzothiophene on NiMoP/γ–Al2O3 catalyst under reactive distillation conditions in a micro trickle bed reactor: solvent and temperature effect

Abstract In this work, the influence of pressure and temperature experimentally applied on reactive distillation (RD) under lower conditions than conventional hydrotreating (HDT) processes, the hydrodesulfurization (HDS) reaction of 4,6–dimethyldibenzothiophene (4,6–DMDBT) molecule and the experimental performance of a down-flow micro trickle bed reactor (micro-TBR) with n–dodecane and decalin were studied. Thermodynamic analyses to evaluate hydrogen solubility in liquid hydrocarbons and evaporation for n–dodecane and decalin as lineal and cyclic representative solvents, respectively, were considered. It was possible to define experimental conditions, producing a small deviation of the plug flow model (PFM) and diminished the gas–liquid (G–L) mass transfer limitation as determined from a reactor model at 2.5 MPa. The axial dispersion model (ADM) and PFM models adjust the experimental data at 2.5 MPa operational pressure and the 4,6–DMDBT conversion obtained was ca. 20–50% using n–dodecane; 1.5 times higher when decalin was using. This behavior was due to the liquid hydrogen fraction of n–dodecane was two times higher than for decalin for all operational pressures. In this sense, the use of n–dodecane as a solvent decreased the mass transfer resistance at the G–L and liquid–solid (L–S) interphases. The internal mass transfer resistance in the G–L interphase not only depends on the diffusivity of the solvent, but it also depends on both, the temperature and hydrogen pressure, finding that the RD conditions with n–dodecane are viable in the treatment of sterically impaired molecules in HDS processes.

Study on the mechanism of hydrodesulfurization of tetrahydrothiophene catalyzed by nickel phosphide

Hydrodesulfurization (HDS) reaction can significantly reduce the viscosity and sulfur content of heavy oil, while the HDS reaction mechanism of tetrahydrothiophene as the main sulfide in heavy oil is still unclear. The HDS experiment of tetrahydrothiophene catalyzed by nickel phosphide (Ni2P) is carried out at 200–300 °C. The results indicate that the H2S production under the catalysis of Ni2P increases obviously within 200–250 °C. The main gas products of HDS reaction are butane, butene and H2S. Meanwhile, the mechanism of tetrahydrothiophene catalyzed by Ni2P is analyzed based on Density Functional Theory (DFT). It is revealed that the adsorption model is most stable when tetrahydrothiophene is vertically adsorbed on the V–Ni-Hcp1 site of Ni2P (001). The C–S bond is elongated and the C–C bond is shortened after adsorption. Hydrogenation (HYD) is the most possible reaction route of tetrahydrothiophene on Ni2P (001) surface. There are two routes with the lowest activation energy, which are C4H8S→C4H8SH∗→C4H9SH∗→C4H10+H2S and C4H8S→C4H9S∗→C4H9∗+SH∗→C4H10+H2S. Butane and H2S are produced in the reaction, corresponding to the experimental results. This study provides a basis for understanding of the HDS mechanism of tetrahydrothiophene catalyzed by Ni2P.

Comparison of the intraparticle diffusion of DBT and 4,6-DMDBT in HDS over different mesostructured silica-based catalysts

Achieving ultradeep hydrodesulfurization (HDS) of diesel necessitates HDS catalyst optimization. Understanding the catalyst pore structure effects on the diffusion behavior of the organosulfur compound benefits the proper design of the HDS catalysts with maximized apparent reactivities. In the present study, we controllably synthesized three mesoporous silica-based catalysts (NiMo/Zr-SBA-15, FDU-12, and MCFs) with similar intrinsic reactivities (∼13 × 10-4 and ∼ 5 × 10-4 mol•g−1•h−1 for DBT and 4,6-DMDBT HDS) but different pore structures. The diffusion behaviors of dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) in pore channels were systematically investigated via the reaction kinetic method. The pore channel/cage sizes rather than the pore mouth/window sizes dominated the intraparticle diffusion. The effective diffusion coefficient (De) decreased in the order of NiMo/Zr-MCFs (19.7 cm2•s−1) > NiMo/Zr-FDU-12 (18.2 cm2•s−1) > NiMo/Zr-SBA-15 (8.2 cm2•s−1) for DBT, while NiMo/Zr-MCFs (7.4 cm2•s−1) > NiMo/Zr-FDU-12 (4.4 cm2•s−1) > NiMo/Zr-SBA-15 (4.2 cm2•s−1) for 4,6-DMDBT. The corresponding correlation with pore size suggested that the intraparticle diffusion resistance can be greatly relieved when the catalyst pore/cage size is > 25x larger than the molecule size of the organosulfur-containing compounds. The findings present fresh opportunities for designing silica-based HDS catalysts for efficient HDS reaction.

HYDRODESULFURIZATION OF CRUDE OIL FRACTIONS USING Co-Mo/Al2O, CATALYST

Kinetic of hydrodesulfurization reaction is studied for crude oil fractions: Vacuum distillate, deasphalted oil, reduced crude oil and vacuum residue

Catalyst particle shapes and pore structure engineering for hydrodesulfurization and hydrodenitrogenation reactions

Catalyst particle shapes and pore structure engineering for hydrodesulfurization and hydrodenitrogenation reactions