Model Diesel Research Articles

The feasibility study of single-hydrocarbylbenzene/n-heptane model diesel fuels for diesel characterization

Single-hydrocarbylbenzenes are an important component of diesel. Understanding the mechanism of single-hydrocarbylbenzenes in engine combustion and emissions is of great significance in the construction and development of model diesel fuels. In this work, we used n-heptane as a representative components of alkanes, and toluene, n-butylbenzene and 1,2, 4-trimethylbenzene as the representative components of aromatic hydrocarbons and studied the effects of toluene/n-heptane, n-butylbenzene/n-heptane, and 1,2,4-trimethylbenzene/n-heptane blend fuels on the combustions and emissions performance of an engine. The test fuels include pure diesel (D100) and other six single-hydrocarbylbenzene/n-heptane blends (toluene, n-butylbenzene and 1,2,4-trimethylbenzene (T20, BBZ20, TMB20 and T30, BBZ30, TMB30) which were added to n-heptane at volume ratios of 20% and 30%). The experimental results showed that the peak IP increased, and CA50 advanced after the addition of single-hydrocarbylbenzenes. The IP, HRR, ID, and CA50 curves of BBZ20 were the most consistent with those of D100. Moreover, the soot emissions of single-hydrocarbylbenzene blended fuels were low, and the NOx, CO, and THC emissions were higher than those of D100. At EGR < 20%, the difference between NOx emissions of D100 and BBZ or TMB was within 2.6%. Under all EGR rates, the soot emissions of BBZ20 were the closest to those of D100 (especially when the EGR rate is 40%, the difference in soot emissions between BBZ20 and D100 is only 57.8%), and the CO emissions of TMB20 closest to those of D100 (the range of difference is 5–13.3%).

An Effective Hybrid Heterogeneous Catalyst to Desulfurize Diesel: Peroxotungstate@Metal-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.

Mesoporous Adsorbents for Desulfurization of Model Diesel Fuel: Optimization, Kinetic, and Thermodynamic Studies

Mesoporous alumina-based adsorbents consisting of a π-electron acceptor complexing agent (2,7-dinitro-9-fluorenone) were synthesized and characterized. Adsorbents were screened for the removal of sulfur compounds from a model ultra-low-sulfur diesel fuel via a charge transfer complex (CTC) mechanism. The sulfur adsorption isotherms and kinetics were examined. The kinetics of sulfur adsorption followed a pseudo-second-order model with the CTC adsorbents. Among the three adsorbents screened, a commercial γ-Al2O3 CTC adsorbent showed the highest desulfurization in a short-run period. The regeneration of spent adsorbent was studied with three different polar solvents, namely chloroform, dichloromethane, and carbon tetrachloride. Dichloromethane was found to be the most suitable solvent for extracting a major portion of sulfur compounds occupied in the pores of the spent adsorbent. γ-Al2O3 CTC adsorbent can be reused after regeneration. Thermodynamic parameters such as Ea, ΔG, ΔH, and ΔS provided a better insight into the adsorption process.

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

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.

Experimental study and mass transfer modelling for extractive desulfurization of diesel with ionic liquid in microreactors

Conventional hydrodesulfurization technology was limited to treat aromatic heterocyclic sulfur compounds in ultralow-sulfur diesel. Extractive desulfurization (EDS) using ionic liquid (IL) exhibited good performance to address these issues, except for its long extraction time (15–40 min). To address this, microreactor was adopted to intensify the IL-based EDS, where dibenzothiophene was extracted from model diesel (MD) as the continuous phase to 1-butyl-3-methylimidazolium tetrafluoroborate as the dispersed phase under segmented flow (which appeared preferably at capillary numbers lower than 0.01). The effects of temperature, residence time and flow rate ratio on the desulfurization efficiency were investigated. The extraction equilibration time could be shortened from more than 15 min in conventional batch extractors to 120 s in microreactors. The extraction process was modeled according to the two-film model applied within a unit cell of the segmented flow, where the mass transfer resistance was considered primarily on the film side of the IL droplet. The mechanism for the improved EDS performance at higher temperatures or larger IL to MD flow ratios was investigated and validated, which was related to the significant increase in the diffusion coefficient or the specific interfacial area. These findings may shed important insights into the precise manipulation of IL-based EDS for a better process design and reactor optimization.

Vanadium Containing Metal‐organic Frameworks as Highly Efficient Catalysts for the Oxidation of Refractory Aromatic Sulfur Compounds

AbstractThe wet impregnation method was applied to prepare vanadium species on the chromium(III) terephthalate metal‐organic framework (MIL‐101) and on the aluminum fumarate metal‐organic framework (A520), two highly efficient catalysts, as well as vanadium species on the zinc terephthalate metal‐organic framework (MOF‐5), using vanadium(V) oxytributoxide as a precursor. The prepared catalysts were characterized by powder X‐ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT‐IR), scanning electron microscopy (SEM), energy‐dispersive spectroscopy (EDX), N2 sorption measurement (BET), thermal analysis (TGA‐DTA), and X‐ray photoelectron spectroscopy (XPS). The prepared materials were utilized as catalysts for the oxidation of the refractory aromatic sulfur compound, dibenzothiophene (DBT), in a model diesel fuel. The catalytic oxidation of DBT to DBT‐sulfone was performed in the presence of tert‐butyl hydroperoxide (TBHP) under mild operating conditions. The heterogeneous catalysts, OV(OtBu)3−x(OH)x@MIL‐101(Cr), OV(OtBu)3−x(OH)x@A520, and OV(OtBu)3−x(OH)x@MOF‐5 demonstrated activities of 98, 98, and 10 %, respectively, in the oxidative desulfurization (ODS) process at 60 °C. The catalysts were recycled easily and reused without a significant decrease in their activity. The oxidation of DBT to DBT‐sulfone was investigated using gas chromatography, and the formation of DBT‐sulfone was confirmed by FT‐IR and 1H NMR spectroscopies.

Adsorptive desulfurization of model diesel fuel over mono-functionalized nickel/γ-alumina and bi-functionalized nickel/cerium/γ-alumina adsorbents

In this study, the S–M direct interaction and π-complexation mechanisms for selective adsorption of 4,6-dimethyldibenzothiophene (4,6-DMDBT) onto the prepared mono-functionalized nickel/γ-alumina (Ni/γ–Al2O3) and bi-functionalized nickel/cerium/commercial γ-alumina (Ce–Ni/γ–Al2O3) were investigated. To characterize the prepared adsorbents, X-ray fluorescence spectroscopy, energy-dispersive X-ray, X-ray diffraction, N2 adsorption–desorption, and temperature-programmed desorption of ammonia (NH3-TPD) were used. The influence of nickel–cerium contents, 4,6-DMDBT and competitive aromatic concentrations on the adsorptive desulfurization performance were also studied. The equilibrium and kinetic data were well described by Langmuir and pseudo-second-order models, respectively. The maximum adsorption capacity of γ-Al2O3, Ni/γ–Al2O3 and Ce–Ni/γ–Al2O3 was found to be 1.253, 15.970 and 17.970 mg/g, respectively. Diffusion studies showed that both π–Ni and S–Ce were the major adsorption mechanisms in the first fast adsorption stage, and the external mass transfer limited the adsorption rate. In the second stage, the adsorption rate was controlled by intra-particle diffusion (R2 = 0.976 for Ni/γ–Al2O3 and R2 = 0.981 for Ce–Ni/γ–Al2O3) confirming that acid–base interaction (S–H) was formed. The results showed that selective binding formation of sulfur compounds on adsorbent active sites was proceeded via π-interaction (π–Ni), direct sulfur–cerium interaction (S–Ce), and acid–base interaction (S–H). The multifunctional Ce–Ni/γ–Al2O3 exhibited a higher adsorptive selectivity for 4,6-DMDBT compared to Ni/γ–Al2O3 in diesel fuel in the presence of aromatic content. The regeneration results showed that the prepared adsorbents can be reused easily for three cycles.

Iron Oxide Catalyst for Oxidative Desulfurization of Model Diesel Fuel

— The catalytic oxidative desulfurization (Cat-ODS) process has been introduced as a new technology to achieve ultra-low sulphur levels in diesel fuels. In this study, the performance of the alumina supported iron oxide based catalysts doped with cobalt, synthesized via wet impregnation method on the Cat-ODS of the model diesel with the total sulphur 500ppm was investigated using tert-butyl hydroperoxide (TBHP) as an oxidizing agent and N,N-dimethylformamide as an extraction solvent. A series of dopant was being screened. Co/Fe-Al2O3 (10:90) and Co/Fe-Al2O3 (20:80) prepared at 400°C. Overall, the catalytic activity decreased as dopant ratio increased. Catalyst with 10 wt% of Co was successfully removed 96% of thiophene, 100% of DBT and 92% of 4,6-DMDBT in model diesel. Further investigation, potential catalyst that calcined at 400°C contributed higher sulphur removal compared to the catalyst calcined at 500°C. X-ray diffraction analysis (XRD) result showed that Co/Fe-Al2O3 (10:90) prepared at 400°C was amorphous, while micrograph of the field emission scanning electron microscopy (FESEM) illustrated an inhomogeneous distribution of various particle sizes. The energy dispersive X-ray analysis (EDX) result have confirmed the presence of Fe and Co in all of the prepared catalyst.

Hydrogen Production via Model Diesel Steam Reforming over a High-Performance Ni/Ce0.75La0.25O2−δ-γ-Al2O3 Catalyst with Oxygen Vacancies

Hydrogen-rich syngas production via diesel steam reforming (DSR) is of great interest because of the high H2/CO ratio and available external heat sources. In this study, catalysts (particle size (dp) = 3–5 mm) containing 10 wt % Ni were prepared through wet impregnation, and their performance was evaluated in a semipilot fixed-bed reactor (Φ = 42 mm). The catalyst was doped with La, which resulted in excellent catalytic performance under different operating conditions. The apparent activation energies of the catalysts for the model diesel (n-dodecane) steam reforming increased in the order Ni/Ce0.75La0.25O2−δ-γ-Al2O3 (17 kJ/mol) < Ni/CeO2-γ-Al2O3 (18 kJ/mol) < Ni/γ-Al2O3 (27 kJ/mol). The model DSR over Ni/Ce0.75La0.25O2−δ-γ-Al2O3 showed product stability and produced a high H2 content (32 vol %). Fresh and spent catalysts were characterized by X-ray diffraction, N2 adsorption–desorption isotherms, H2-temperature programmed reduction, inductively coupled plasma–mass spectrometry, X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, and thermogravimetric analysis. The origin of the oxygen vacancies in the La-doped catalyst was elucidated using density functional theory calculations. The improvements in the activity and stability of the Ni/Ce0.75La0.25O2−δ-γ-Al2O3 catalyst are attributed to (1) the enhancement in the oxygen release/storage capacity, (2) the stabilizing interaction between Ni and the surface La2O3 phase, and (3) the small size (11 nm) and uniform distribution of Ni particles. Out of the tested catalysts, the spent Ni/Ce0.75La0.25O2−δ-γ-Al2O3 catalyst showed the lowest coke deposition (5.8 mg/g-cat.) and the least severe Ni agglomeration after 10 h of testing because of its superior ionic mobility and oxygen storage capacity.

High Catalytic Efficiency of a Layered Coordination Polymer to Remove Simultaneous Sulfur and Nitrogen Compounds from Fuels

An ionic lamellar coordination polymer based on a flexible triphosphonic acid linker, [Gd(H4nmp)(H2O)2]Cl2 H2O (1) (H6nmp stands for nitrilo(trimethylphosphonic) acid), presents high efficiency to remove sulfur and nitrogen pollutant compounds from model diesel. Its oxidative catalytic performance was investigated using single sulfur (1-BT, DBT, 4-MDBT and 4,6-DMDBT, 2350 ppm of S) and nitrogen (indole and quinolone, 400 ppm of N) model diesels and further, using multicomponent S/N model diesel. Different methodologies of preparation followed (microwave, one-pot, hydrothermal) originated small morphological differences that did not influenced the catalytic performance of catalyst. Complete desulfurization and denitrogenation were achieved after 2 h using single model diesels, an ionic liquid as extraction solvent ([BMIM]PF6) and H2O2 as oxidant. Simultaneous desulfurization and denitrogenation processes revealed that the nitrogen compounds are more easily removed from the diesel phase to the [BMIM]PF6 phase and consequently, faster oxidized than the sulfur compounds. The lamellar catalyst showed a high recycle capacity for desulfurization. The reusability of the diesel/H2O2/[BMIM]PF6 system catalyzed by lamellar catalyst was more efficient for denitrogenation than for desulfurization process using a multicomponent model diesel. This behavior is not associated with the catalyst performance but it is mainly due to the saturation of S/N compounds in the extraction phase.

Keggin-POM@rht-MOF-1 composite as heterogeneous catalysts towards ultra-deep oxidative fuel desulfurization

POM@MOF composites have aroused much concern regarding their amazing catalytic performance, reliable stability and recyclability; however, it remains great challenge on synthesizing expected POM@MOF composites and catalyzing organic reactions. Herein, a series of three Keggin-POM@rht-MOF-1 (POM = H3+nPMo12-nVnO40, n = 1, (Mo11V1); n = 2, (Mo10V2); n = 3, (Mo9V3)), have been isolated by using a large internal cavity window of rht-MOF-1 to encapsulate the guest molecules of Keggin-POM. X-ray crystallographic analysis reveals that Keggin-POM@rht-MOF-1 composites are of high load efficiency and chemical stability. Upon employed as catalysts on the desulfurization reaction of model diesels and real diesels, the as-synthesized Keggin-POM@rht-MOF-1 composites exhibit high percent conversion of desulfurization up to 96% by Mo9V3 and 90% by Mo9V3, respectively. Its derivatives from both the advantages of the host of rht-MOF-1) and the Keggin-POM guest. The size-matched rht-MOF-1 prevented the leaching of Keggin-POM, while the Keggin-POM retain the reachability of dibenzothiophene (DBT), 1-benzothiophene (BT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) for the catalyzing the oxidation reactions.

Polyoxometalate@Periodic mesoporous organosilicas as active materials for oxidative desulfurization of diesels

Abstract Novel material catalysts based in the active zinc-substituted polyoxotungstate ([PW11Zn(H2O)39]5-, abbreviated as PW11Zn) were efficiently used in the oxidative desulfurization of real and model diesels. These active catalytic center was strategically immobilized in a less hydrophilic periodic mesoporous organosilicas (PMOs), containing ethane-bridge (PMOE) and benzene-bridge (PMOB) walls, functionalized with (3-aminopropyl)triethoxysilane (aptes). The efficiency of the novel catalytic composites (PW11Zn@aptesPMOE and PW11Zn@aptesPMOB) was studied under oxidative desulfurization system (CODS) without the presence of an extraction solvent and also using a biphasic (diesel/extraction solvent) oxidative desulfurization system (ECODS). Both composites presented higher desulfurization efficiency under the solvent-free system, reaching ultra-low levels of sulfur compounds after only 1 h and using low ratio of H2O2/S = 4. The catalysts could be recycled without loss of activity for ten consecutive cycles. However, after the first desulfurization cycle complete desulfurization was achieved within only 30 min using PW11Zn@aptesPMOE composite. Also, the structure of PW11Zn@aptesPMOE demonstrated to be more stable than PW11Zn@aptesPMOB, probably due to the occurrence of some PW11Zn leaching from the PMOB surface, probably caused by the lower interaction of PW11Zn with the benzene-bridge PMOB wall. The most robust catalyst PW11Zn@aptesPMOE was used to desulfurize a real diesel achieving 75.9% of desulfurization after 2 h. The catalyst was further recycled with success to treat real diesel.

Desulfurization of diesel by extraction coupled with Mo-catalyzed sulfoxidation in polyethylene glycol-based deep eutectic solvents

Oxidative desulfurization (ODS) is a method of removing sulfur from diesel fuel that has the potential to complement or even replace conventional hydrodesulfurization processes in oil refineries. One of the most promising variants of ODS is extractive and catalytic ODS (ECODS) in which the organic sulfur compounds in the liquid fuel are oxidized and extracted in situ from the oil phase into an extractant phase. In this study, the desulfurization of model and real diesel fuel has been performed in ECODS systems employing two different types of deep eutectic solvents (DESs), prepared by combining polyethylene glycol (PEG) as hydrogen bond donor with tetrabutylammonium chloride (TBACl) or choline chloride (ChCl) as hydrogen bond acceptor. The ECODS systems were evaluated with the complexes [MoO2Cl2(DMB)2] (1) and [MoO2Cl2(DEO)] (2) (DMB = N,N-dimethylbenzamide, DEO = N,N′-diethyloxamide) as catalysts and 30 wt% H2O2 as oxidant. The effects of different reaction conditions, such as the amount of catalyst, H2O2 and DES, and reaction temperature, were investigated. The combination of complex 1 with the DES ChCl/PEG showed the best performance for the removal of dibenzothiophene, 4-methyldibenzothiophene and 4,6-dimethyldibenzothiophene from a high‑sulfur (3000 ppm) model diesel, allowing a desulfurization efficiency of 99.6% to be attained at 70 °C within 2 h. By applying the optimized model diesel ECODS systems to the treatment of a commercial untreated diesel with a sulfur content of 2300 ppm, 82% of sulfur compounds could be eliminated. These promising results indicate that DESs are a viable alternative to ionic liquids as extraction solvents in ECODS processes.

Batch and Continuous Adsorptive Desulfurization of Model Diesel Fuels Using Graphene Nanoplatelets

An experimental investigation on adsorptive desulfurization for model diesel fuels (MDFs) is described using graphene nanoplatelets (GNPs) as an adsorbent. Batch experiments for a single component ...

Deep Oxidative Desulfurization of Fuels in the Presence of Brönsted Acidic Polyoxometalate-Based Ionic Liquids.

Polyoxometalate-based ionic liquid hybrid materials with a pyridinium cation, containing Brönsted acid sites, were synthesized and used as catalysts for the oxidation of model and real diesel fuels. Keggin-type polyoxometalates with the formulae [PMo12O40]3−, [PVMo11O40]4−, [PV2Mo10O40]4−, [PW12O40]3− were used as anions. It was shown that increasing the acid site strength leads to an increase of dibenzothiophene conversion to the corresponding sulfone. The best results were obtained in the presence of a catalyst, containing a nicotinic acid derivative as cation and phosphomolybdate as anion. The main factors affecting the process consisting of catalyst dosage, temperature, reaction time, oxidant dosage were investigated in detail. Under optimal conditions full oxidation of dibenzothiophene and more than a 90% desulfurization degree of real diesel fuel (initial sulfur content of 2050 ppm) were obtained (the oxidation conditions: NK-1 catalyst, molar ratio H2O2:S 10:1, molar ratio S:Mo 8:1, 1 mL MeCN, 70 °C, 1 h). The synthesized catalysts could be used five times with a slight decrease in activity.

Desulfurization of model and real fuels by extraction and oxidation processes using an indenylmolybdenum tricarbonyl pre‐catalyst

Regulations on the permissible levels of sulfur in transportation fuels are becoming ever more strict, with a global shift towards “zero sulfur” fuels, and the revamp of existing hydrodesulfurization (HDS) facilities to meet these lower caps is cost‐prohibitive. Metal‐catalyzed sulfoxidation chemistry is viewed as an economically viable desulfurization strategy that could complement conventional HDS technology. In the present work, the complex [η5‐IndMo(CO)3Me] (1) (Ind = indenyl) was employed in the catalytic oxidative desulfurization (CODS) of model and real liquid fuels, using aqueous hydrogen peroxide (H2O2) as oxidant. After optimization of the CODS reaction parameters (diesel/H2O2 ratio, catalyst amount, temperature), a high‐sulfur (2000 ppm) model diesel containing benzothiophene, dibenzothiophene, 4‐methyldibenzothiophene and 4,6‐dimethyldibenzothiophene could be completely desulfurized within 2 hr under solvent‐free conditions or in the presence of the ionic liquid 1‐butyl‐3‐methylimidazolium hexafluorophosphate ([BMIM]PF6) as extraction solvent. The catalyst formed under solvent‐free conditions could be recycled without a significant decrease in desulfurization activity. The high performance of the CODS system was verified in the sulfur removal from a commercial untreated diesel fuel with a sulfur content of 2300 ppm, and a jet fuel with a sulfur content of 1100 ppm. Solvent‐free CODS in combination with initial/final extraction gave desulfurization efficiencies of 70% for the diesel fuel and 55% for the jet fuel. CODS with [BMIM]PF6 in combination with initial/final extraction led to a sulfur removal of 95.9% for the diesel fuel, which is one of the best results yet reported for ODS of commercial diesels.

Performance of Diesel Soot Oxidation in the Presence of Ash Species

This paper studies the impact of ash component, ash particle diameter, soot particles (Printex U, PU)/ash stratification method, and PU/ash mixing ratio on the oxidation process by the thermogravimetric method. Compared with PU/Al2O3 and PU/MgO mixtures, the PU/ZnO mixture has the lowest peak temperature 560 °C and the highest comprehensive oxidation index 2.15 × 10–7%2 min–2 °C–3. ZnO particles (50 nm) lead to lower peak temperature and larger comprehensive oxidation index compared with 200 nm ZnO particles. The tight contact stratification method is better than other ash up and ash down stratification methods because of the heat transferring and the diffusion of oxygen within the particle stratification methods. The 1:15 wt ratio is the best ratio between PU/ZnO particles. The maximum comprehensive oxidation index is 2.21 × 10–7%2 min–2 °C–3, and the minimum peak temperature is 545 °C. Compared with the pure PU, the comprehensive oxidation index and minimum peak temperature improve 126 and 12%, respectively. This study is beneficial for modeling diesel particulate filter regeneration and designing efficient regeneration techniques.

Creation of Active Sites in MOF‐808(Zr) by a Facile Route for Oxidative Desulfurization of Model Diesel Oil

AbstractMOF‐808(Zr) as an important member of metal‐organic frameworks (MOFs) has attracted much attention due to its good stability, large surface area and rich zirconium metal centers. However, Zr sites in the structure of MOF‐808(Zr) are inactive in many catalytic reactions due to they are well coordinated with organic ligands like 1,3,5‐benzenetricarboxylic acid (BTC) and formate anions. Thus, removing formate anions have been attempted to create more active sites in the structure for many reactions while maintaining the structural stability. In this work, we report that the formate ligands in MOF‐808(Zr) can be facilely removed by the treatment in hot ethanol for 4 h. The obtained material as a heterogeneous catalyst exhibited superior catalytic activity in the oxidative desulfurization (ODS) reaction of dibenzothiophene (DBT) compared with reported MOFs catalysts. The conversion of DBT in model diesel oil could reach &gt;99 % within a reaction time of 20 min at 323 K, which is five times as that over parent MOF‐808(Zr). As a result, the sulfur content was decreased from 1000 ppm to less than 10 ppm. Such catalytic performance should be mainly attributed to the creation of more active sites in the structure of MOF‐808(Zr) after the removal of formate anions.

Tailoring Electronic Properties of Porphyrin Manganese on Boron Nitride for Enhancing Aerobic Oxidative Desulfurization at Room Temperature

Tailoring electronic properties of the central metal atom of metalloporphyrin has emerged as a practical approach to acquire a high catalytic performance. Herein, 5,10,15,20-tetraphenylporphyrin manganese chloride (TPPMnCl) was immobilized on hexagonal boron nitride (h-BN) and employed as a catalyst to achieve ultradeep aerobic oxidative desulfurization of diesel at room temperature. The interfacial electronic effect on the TPPMnCl induced by the h-BN was embraced, leading to an electron transfer from Mn to h-BN. The resulting high-valence Mn could facilitate the generation of reactive oxygen species from the reduction of oxygen. As a result, 99.2% of refractory aromatic sulfur removal for model diesel could be achieved at 30 °C using immobilized TPPMnCl and oxygen as the catalyst and oxidant, respectively. Besides, the catalytic mechanism was studied in detail, and the peroxyacid was found to be generated on the immobilized TPPMnCl as the active species. This study provides a strategy toward tailoring th...

Mesoporous zirconium–silica nanocomposite modified with heteropoly tungstophosphoric acid catalyst for ultra‐deep oxidative desulfurization

An adsorbent catalyst was proposed to reduce the leaching of active species of the catalyst and enhance the kinetics of the oxidative desulfurization (ODS) reaction of dibenzothiophene (DBT) from model diesel fuel. By loading phosphotungstic acid (HPW) species onto a zirconium‐modified hexagonal mesoporous silica (Zr‐HMS), a novel catalyst was synthesized and utilized for the ODS process. An ultrafast ODS kinetics was specifically identified using 20%HPW/Zr‐HMS as catalyst. Within 30 min, more than 95% of the 350 ppm DBT content of the model fuel was oxidized by H2O2. The synthesized catalyst retained its sulfur removal ability even after five subsequent ODS reactions and the leaching of HPW species was found to be suppressed successfully. Overall, this new reusable catalyst provided an alternative for highly efficient ultra‐deep desulfurization process.