Naphthalene Conversion Research Articles

Highly selective production of 2-methylnaphthalene by CO2 hydrogenation and naphthalene alkylation

Many researchers have extensively studied the alkylation of naphthalene with methanol for the preparation of high-value-added chemicals, especially methylnaphthalenes (MNs). Studies indicated that methanol generates a large number of methanol-to-olefin by-products on zeolites, resulting in low selectivity of the target product and poor stability of the catalyst, limiting its application in the industrial field. In this study, CO2 hydrogenation was coupled with naphthalene alkylation, and the H3CO* active intermediate generated in situ was alkylated with naphthalene by using metal oxide-zeolite (OX-ZEO) bifunctional catalysts, which exhibited the ‘slow release’ phenomenon of the methylation reagent. It improved naphthalene conversion, suppressed deep alkylation and coke deposition side reactions and kept the catalyst stable for up to 500 h. A high-density and medium-strength Brønsted acid center facilitated the efficient migration of H3CO* active intermediates with the desorption of 2-methylnaphthalene (2-MN), which was particularly important for improving naphthalene conversion and 2-MN selectivity. The in situ IR showed that more Brønsted acid sites of Ga-S-1 effectively pulled the migration process of H3CO* species to the zeolitic acid center and increased the efficiency of C-C coupling compared to ZSM-5, which promoted the alkylation of H3CO* species with naphthalene. The results of chemisorption experiments showed that the medium-strength Brønsted acid site, which promoted the desorption of 2-MN, inhibited the deep alkylation reaction. The 2,6-dTBPy-IR results showed that the presence of fewer Brønsted centers on the outer surface of Ga-S-1 further optimized the product distribution and enhanced the selectivity of 2-MN in MNs to more than 90 %. Under optimal conditions, 80.1 % selectivity for MNs was obtained via ZnZrOx&Ga-S-1 bifunctional catalysts, with 97.4 % selectivity for 2-MN in MNs.

Research on reaction mechanisms on chemical looping gasification of naphthalene over NiFe2O4 for syngas production: An experimental and theoretical study

The effective removal of tar during biomass gasification is a significant challenge that can be addressed by chemical looping gasification (CLG), which offers a promising alternative for converting biomass into syngas with reduced tar generation. In this study, we investigated the mechanism of CLG of naphthalene as a model biomass tar compound over NiFe2O4 to produce syngas. Both experimental and simulation results indicate the optimal operating conditions for syngas production are 1000℃ and an O/C ratio of 1:1. Under the optimal reaction conditions, the experimental and simulated CO yields were 67 vol% and 73 vol%, respectively, while H2 yields were 22 vol% and 24 vol%. Additionally, carbon conversion rates reached 78% and 76%. Thermodynamic calculations and molecular dynamics simulations revealed that the reactions proceed spontaneously, with increasing temperature favoring naphthalene conversion and syngas production. Density functional theory results indicate that the reaction pathway centered on the carbon at the α-position is the key to naphthalene and NiFe2O4 conversion. The optimal reaction pathways for H2 and CO formation were explored. This study on the CLG of naphthalene over NiFe2O4 provides a theoretical basis for the development of more efficient CLG processes with reduced tar formation.

Effective abatement of naphthalene from flue gas by V-W/Ti catalyst: Study of vanadium species and reaction mechanism

The removal of naphthalene is important but deficient, so that the available V-W/Ti catalysts (1.0 wt% V2O5/TiO2) were prepared for its efficient abatement in this work. Especially, influences of different existence status of vanadium species on naphthalene elimination were investigated via changing the pH value of precursor solution. With the increase of precursor solution acidity, more highly polymeric vanadium species were formed on the catalyst surface. The redox capability was enhanced markedly as a consequence of the stronger electron transfer between V/W and Ti that induced more surface active oxygen and V5+, whereas the catalytic activity was obviously boosted and almost 90 % conversion of naphthalene was achieved at 293 °C. Moreover, the weaker chemisorption between naphthalene and V-W/Ti catalyst allowed the deeper conversion to COx. GC–MS manifested that naphthalene seemed to be an organic component that was difficult to be totally degraded. Naphthalene oxidation was in the following pathway of naphthalene → 1,4-naphthoquinone → phthalic anhydride → phthalates → benzene → benzoquinone → maleic anhydride → COx/H2O. The opening of aromatic ring in phthalic anhydride and benzene ring in benzene were proven to be the rate-controlling step based on in-situ DRIFTS results. The key of naphthalene oxidation was the complete degradation of various intermediates.

Pressurized hydrogasification and cobalt-catalyzed hydrogasification behaviors of naphthalene as a coal-based model compound

The pressurized hydrogasification/catalytic hydrogasification behaviors of naphthalene as a coal-based model compound were investigated for the first time in a batch reactor. The composition of products was roundly analyzed by gas chromatography (GC), gas chromatography–mass spectrometer (GC-MS) and laser desorption time-of-flight mass spectrometry (TOF-MS). Based on the product analysis results, the detailed reaction pathways for naphthalene hydrogasification and the effects of cobalt on reaction pathways were elucidated. Naphthalene first destabilized during hydrogasification. Subsequently, the destabilized naphthalene either underwent stepwise hydrocracking by active hydrogen atoms to ultimately produce benzene and methane, or formed naphthalene free radicals to initiate condensation. Cobalt can regulate products distribution to boost methane, benzene and toluene yield by facilitating active hydrogen generation, despite it had a limited ability to facilitate the naphthalene destabilization at temperature below 700 °C. Whereas above 750 °C, cobalt can promote naphthalene destabilization, thereby remarkably enhancing the conversion of naphthalene. Furthermore, cobalt intensified condensation leading to a shift of molecular mass distribution of condensation products from 252 ∼ 500 Da to 750 ∼ 2000 Da. These phenomena supported similar findings in coal catalytic hydrogasification. The rise in temperature, initial H2 pressure (P0), and cobalt content all facilitated the cobalt catalyzed naphthalene hydrocracking to gaseous product, with temperature exerting a particularly significant effect. This trend was similar with cobalt catalyzed coal hydrogasification. For example, when temperature increased from 650 ℃ to 750 ℃, naphthalene conversion improved from 21.2 % to 49.6 %, and gas yield rose from 2.6 % to 29.4 % at 1 % Co and 1.3 MPa P₀. The investigation serves to shed light on the molecular-level understanding of the mechanism underpinning coal hydrogasification.

Calcium-Poison-Resistant Cu/YCeO2-TiO2 Catalyst for the Selective Catalytic Reduction of NO with CO and Naphthalene in the Presence of Oxygen.

The pollution from industrial processes based on biomass combustion is still an ongoing problem. In the present contribution, the selective catalytic reduction of NO with CO and naphthalene is carried out in the presence of 10% oxygen. The accumulation of alkaline and alkaline earth metals during biomass combustion is here simulated by the addition of calcium to a Cu-impregnated YCeO2-TiO2 support. The results show that a high dispersion of copper is obtained, which is resistant to the accumulation of calcium. Full conversion of CO and naphthalene is achieved above 200 °C, whereas NO conversions of 80, 90, and 87% are obtained for the catalysts with Ca loadings of 2.6, 5.2, and 13%, respectively, at 350 °C. It is proposed that the high activity of the catalysts is ascribed to the formation of Cu-Ox-Ce species and that the accumulation of Ca acts as a barrier to avoid copper sintering. It was found that different forms of carbonate and nitrite/nitrate species form during reaction, coexisting as adsorbed species during the SCR reaction. The selectivity to N2 was almost 100% in all cases, due to the small presence of NO2 in the reactor outlet (no N2O was detected in any conditions).

Sulfur Vacancies are the Active Sites in the Iron Sulfide Catalyst for the Hydrogenation of Naphthalene

AbstractIron sulfide catalysts could boost the hydrogenation of polycyclic aromatic hydrocarbons, and have been widely employed in direct coal liquefaction owing to their low price and good activity. In the past, the Fe deficient structure on Fe1−xS was normally considered as the active site. Herein, the promotion effect of S vacancies on the performance in the naphthalene hydrogenation reaction was revealed. Additional S vacancies on the prepared Fe1−xS catalyst were introduced by a heat‐treatment under H2. Multiple characterization techniques verified that the density of S vacancies on catalyst surface increased with the prolonged H2 treatment time, while the Fe deficient structure displayed an opposite trend. The performance in the hydrogenation of naphthalene to tetralin was used to evaluate the catalyst activity. It was found that the sequence of naphthalene conversion over catalysts was consistent with the corresponding content of S vacancies, indicating that S vacancies were more efficient active sites. DFT calculation results revealed that both molecular H2 and naphthalene exhibited a pronounced inclination towards adsorption on S vacancies as compared to intact surface of Fe1−xS. The increasing amount of S vacancies facilitated the adsorption of reactants and the weakening of naphthalene C−C bonds.

Simultaneous removal of naphthalene and NOx over V-Ce/Ti catalyst: Design of separated active sites for naphthalene degradation and SCR reaction

V-Ce/Ti catalysts were prepared for the removal of naphthalene and NOx in the flue gas. The adverse effects of NH3 and NO on the naphthalene degradation were weakened on V-Ce/Ti, resulting in a decrease of only 2.5 % in COx selectivity. The formation of high molecular weight byproducts was also reduced. Besides the acid sites on the catalysts, Ce introduced new Brønsted basic sites, which could also adsorb and degrade naphthalene into naphthol effectively. With the separated active sites for naphthalene degradation and NO removal, the reaction between NH3 and the intermediates during the naphthalene degradation was also inhibited, decreasing the formation and accumulation of phthalimide. The oxidation of the intermediates was promoted by active V5+ introduced by Ce, inhibiting the transformation of the intermediates to higher molecular weight byproducts. Nearly 100 % conversion of naphthalene and NO, as well as 40.1 % of the COx selectivity were obtained on V-Ce/Ti.

Catalytic performance and acidic analysis of chloroaluminate ionic liquid with various impurities in the synthesis of multi-octylnaphthalene base oil

The effects of the structure and concentration of impurities on the alkylation of naphthalene with 1-octene catalyzed by chloroaluminate ionic liquid (IL) were investigated. The presence of impurities containing oxygen and nitrogen led to a decrease in the catalytic performance of chloroaluminate IL. As the water concentration increased to 65 mg·g–1, the total selectivity of multi-octylnaphthalene gradually decreased to 42.33%, and the average friction coefficient of the multi-octylnaphthalene base oil gradually increased to 0.201. When the concentration of impurities increased to a critical value, the chloroaluminate IL began to deactivate, leading to a decrease in naphthalene conversion. The critical concentrations for ethanolamine, water, methanol, ether, and diisopentyl sulfide were 33 mg·g–1, 65 mg·g–1, 67 mg·g–1, 87 mg·g–1, and 123 mg·g–1, respectively. Impurities with higher basicity resulted in an earlier onset of chloroaluminate IL deactivation. The changes of Lewis and Brønsted acids in chloroaluminate IL under the influence of impurities were investigated using in situ IR and 27Al NMR spectroscopy. 2,6-dimethylpyridine as an indicator could detect the changes of Brønsted acid in chloroaluminate IL better, but the changes of Lewis acid were not obvious because of the overlap between the characteristic peaks. 2,6-dichloropyridine as an indicator could exclusively detect the changes of Lewis acid in chloroaluminate IL. With the increase in water concentration, the Lewis acid in chloroaluminate IL was continuously consumed and converted into Brønsted acid, and the Lewis acid gradually decreased, while the Brønsted acid showed a change of increasing first and then decreasing.

Ultrafine Pt particles on hollow hierarchical porous β zeolites for selective hydrogenation of naphthalene

It is crucial to develop effective heterogeneous catalysts for the production of decalin as a high-density liquid hydrogen storage material from naphthalene hydrogenation. In this work, hollow hierarchical Pt/Hβ catalysts with ultrafine Pt particles were successfully synthesized successfully. The construction of hollow cavity optimized the metal-support interaction and reduced the resistance of mass diffusion. The ultrafine Pt species could expose more active sites for effective hydrogenation of naphthalene. The optimized Pt/Hβ-2 with hollow structure catalyst displayed the remarkable catalytic performance with the naphthalene conversion of 94.2 % and the decalin yield of 81.4 % at 220 °C, which was superior to the reaction performance of the catalysts reported in the literature under similar reaction condition. Besides, Pt/Hβ-2 presents higher turnover frequency (25.4 h−1) and reaction rate constant (9.9 × 10-3 min−1), which is because of the relatively low activation energy (30.86 kJ mol−1) for the naphthalene hydrogenation.

Hierarchical porous Pt/Hβ catalyst with controllable acidity for efficient hydrogenation of naphthalene

A series of hierarchical porous Pt/Hβ catalysts with different mesopores-acidity were synthesized without using secondary template. The pore structures of the catalysts were altered by constructing mesopores through alkali etching to reduce the mass transfer resistance. Moreover, the metal-support interaction (MSI) was optimized to improve the dispersion of the Pt metal particles. The smaller metal species could expose more active sites during the hydrogenation process, along with a more pronounced electron-deficiency effect. Furthermore, the effect of acid sites distribution on the hydrogenation reaction path and product distribution were also investigated. The strong acid-mesopores-metal factor (X) was defined to describe the relationship with the yield of decalin. The yield of decalin was well correlated with a high R2 value of 0.97. The Pt/Hβ-75 catalyst showed the best synergistic effect between acidity, mesopore and Pt species, leading to the optimal naphthalene conversion (96.7%) and higher yield of decalin (76.7%) at a relatively low temperature, which exhibited a better activity than other catalysts reported in literature for hydrogenation of naphthalene at a similar reaction condition. Besides, the hydrogenation reaction mechanism of naphthalene over Pt supported catalysts was further investigated by density functional theory, and the effect of Pt NPs size on the catalytic reaction process and activity was preliminarily revealed.

Ab initio kinetics of OH-initiated oxidation of naphthalene: A comprehensive revisited study

Naphthalene, the most prevalent and smallest member of the Polycyclic Aromatic Hydrocarbons (PAHs) family, has garnered significant scientific attention for its harmful environmental impacts and those of its degradation products. In this work, we comprehensively recharacterized the gas-phase reaction of naphthalene with OH radicals in a wide range of conditions (T = 200–2000 K &P = 0.76–7600 Torr), covering both atmospheric and combustion chemistry. Within the Rice–Ramsperger–Kassel–Marcus (RRKM)-based master equation framework, the detailed kinetic model was constructed on the potential energy surface explored at the ROCBS-QB3//M06–2X/aug-cc-pVTZ level of theory. Our model not only helps to resolve the existing large discrepancy (up to ∼1000 times) among the previously reported rate constants but also reveals mechanistic insights, including time-resolved species profiles and product distribution, for naphthalene transformation. It is shown that although naphthalene cannot be considered a persistent organic compound (POP) due to its rapid reaction with OH radicals, its chemical conversion can generate harmful substances such as O3 and carcinogenic derivatives. Also, the detailed conversion of naphthalene in water was investigated for the first time, revealing that naphthalene and its important degradation products pose a significant danger to aquatic life as hazardous pollutants.

Methods used to determine the structure of the oxygenase component of naphthalene 1,2 dioxygenase.

Rieske non-heme iron oxygenases are ubiquitously expressed in prokaryotes. These enzymes catalyze a wide variety of reactions, including cis-dihydroxylation, mono-hydroxylation, sulfoxidation, and demethylation. They contain a Rieske-type [2Fe-2S] cluster and an active site with a mono-nuclear iron bound to a 2-His carboxylate triad. Naphthalene 1,2 dioxygenase, a representative of this family, catalyzes the conversion of naphthalene to (+)-cis-(1R,2S)-dihydroxy-1,2-dihydronaphthalene. This transformation requires naphthalene, two electrons, and an oxygen molecule. The first structure of the terminal oxygenase component of a Rieske non-heme iron oxygenase to be determined was naphthalene 1,2 dioxygenase (NDO-O). In this article, we describe in detail the methods used to recombinantly express and purify NDO-O in rich and minimal salts media, the crystallization of NDO-O for structure determination by X-ray crystallography, the challenges faced, and the methods used for the preparation of enzyme ligand complexes. The methods used here resulted in the determination of several NDO-O complexes with aromatic substrates, nitric oxide, oxygen molecule, and products, leading to an initial understanding of the mechanism of enzyme catalysis and the molecular determinants of the regio- and stereo-specificity of this class of enzymes.

Effect of Quinoline Additions on the Activity of In Situ Formed NiWS Catalysts

The effect of quinoline additions and amount of the sulfiding agent added on the activity of the in situ prepared NiWS catalyst in naphthalene hydrogenation was studied. In the presence of 1 wt % quinoline, the obtained catalyst shows high activity (95% naphthalene conversion). The physicochemical properties of the catalyst were studied by XPS, X-ray diffraction analysis, and TEM. At the W : substrate molar ratio of 1 : 40 and 360°С, an increase in the amount of the sulfiding agent from 1 to 5 wt % leads to a decrease in the selectivity with respect to decalins from 68 to 39%, respectively. The degree of decoration with nickel on adding 1 wt % sulfiding agent is 0.1. As the amount of the sulfiding agent added is increased to 5 wt %, the degree of decoration with nickel increases to 0.3.

Utilisation of coal tar naphthalene oil fractions for the synthesis of value-added chemicals: alternative paths to mono- and di-methylnaphthalenes

This study investigates the utilisation of coal tar naphthalene oil fraction (CTNOF), an economical by-product derived from the iron-steel industry, for the production of valuable chemicals, with a particular focus on methylnaphthalenes (MNs) and dimethylnaphthalenes (DMNs). Of specific interest is 2,6-dimethylnaphthalene (2,6-DMN), a pivotal component in the manufacture of polyethylene naphthalate (PEN). The intricate and costly nature of 2,6-DMN production currently poses challenges to the commercial viability of PEN. This study provides the potential heterogeneous reaction pathways for the synthesis of MNs and DMNs via methylation, disproportionation, and isomerisation of CTNOF. The utilisation of CTNOF was investigated in a laboratory-scale fixed bed reactor operating at atmospheric pressure using a mixture of CTNOF: methanol having 1:5 mass ratio over HBeta zeolite catalyst at a temperature of 400 °C and weight hourly space velocity of 2 h−1. The results reveal the successful methylation of CTNOF over the HBeta zeolite catalyst, initially achieving high naphthalene conversion, particularly into 2-MN. This highlights the potential of CTNOF as an alternative feedstock for the production of value-added chemicals. While naphthalene conversion initially reaches 99 wt% within 0.5 h of operation, it gradually decreases to approximately 10 wt% over extended run times. Notably, coke deposition significantly deactivates the HBeta zeolite catalyst during CTNOF methylation, impacting naphthalene conversion. A substantial proportion of naphthalene compounds convert to methylnaphthalenes early in the reaction, predominantly 2-MN, increasing from 14 wt% (in CTNOF feedstock) to 87 wt%. Among DMNs, selectivity for 2,6-DMN, 2,7-DMN, 1,3-DMN, and 1,7-DMN increases, while other DMN isomers exhibit a sharp decrease in selectivity. The distribution of 2,6-triad DMNs rises from 38 wt% in feedstocks to 52–55 wt% with extended reaction times, attributed to MN conversion to DMNs and potential isomerisation from other DMNs. This study underscores the feasibility of using CTNOF for the direct synthesis of valuable chemicals, specifically 2,6-DMN and 2-MN, through methylation over HBeta zeolite catalysts. However, it emphasises the critical role of residence time in coke deposition and the need for optimisation, particularly regarding this parameter, to ensure the efficiency of this catalytic process.

Reductive Transformation of O-, N-, S-Containing Aromatic Compounds under Hydrogen Transfer Conditions: Effect of the Process on the Ni-Based Catalyst.

The influence of the reaction medium on the surface structure and properties of a Ni-based catalyst used for the reductive transformations of O-, N-, and S-containing aromatic substrates under hydrogen transfer conditions has been studied. The catalysts were characterized by XRD, XPS, and IR spectroscopy and TEM methods before and after the reductive reaction. It has been shown that the conversion of 1-benzothiophene causes irreversible poisoning of the catalyst surface with the formation of the Ni2S3 phase, whereas the conversion of naphthalene, 1-benzofuran, and indole does not cause any phase change of the catalyst at 250 °C. However, after the indole conversion, the catalyst surface remains enriched with N-containing compounds, which are evenly distributed over the surface.

Experimental and artificial intelligence study on catalytic reforming of tar over bio-char surface coupled with hydrogen production

Tar problem is an obstacle in biomass gasification. Naphthalene was used as tar model compound to investigate the tar catalytic removal over char bed coupled with hydrogen production. The influence of char properties, residence time and atmosphere on tar reduction was taken into consideration. Results show pinewood char acted as quite good performance for catalytic removal of naphthalene. With the increasing of duration time, deactivation would occur, which brought down the tar conversion efficiency. The addition of H2O could inhibit the carbon deposition and promote hydrogen yield via in-situ gasification. At 800 °C, the naphthalene conversion rate slightly declined to 95.77% even at 182 min under 10% steam atmosphere. The H2 yield was around 8.98 mol/(mole of naphthalene) at initial 12 min. The pinewood char pore analysis results confirmed the inhibition of carbon deposition by steam. Artificial neural network (ANN) models coupled with genetic algorithm (GA) and particle swarm optimization (PSO) were built for prediction of naphthalene conversion and hydrogen yield. The BET surface area, potassium content, penetration time, duration time, temperature and atmosphere were used as input variables. Modeling results show that the PSO-ANN model and relative impact analysis could be effectively used for modeling and analysis of tar catalytic conversion over char bed.

Tailored production and application of biochar for tar removal

The impact of biochar modification on its behavior towards the adsorption and cracking of naphthalene (in a mixture naphthalene/toluene) as tar model compound has been investigated. Both tar adsorption and cracking may be considered alternative tar cleaning technologies which enable its further energetic use. Biochars were produced using different feedstocks and process conditions to tune their physico-chemical and morphological properties. Beech wood, representative of woody biomass, and almond shell and rice husk, representative of agricultural residues, were used. Furthermore, beech wood was also washed with deionized water and doped with KCl and FeSO4. Biochars were produced at 700 °C under several atmospheres (pure N2 and mixtures of N2, CO2, H2O, and CO), resulting in different physico-chemical properties and thus naphthalene adsorption and cracking behavior. Naphthalene adsorption experiments were performed at 250 °C and naphthalene cracking experiments were carried out at 750 °C and 850 °C. The performance of the investigated biochars towards naphthalene adsorption and cracking depended strongly on the production conditions, with biochars produced under reactive atmosphere (including N2, CO2, and H2O) yielding the best behavior. For naphthalene adsorption, an easily accessible high surface area seemed to be the dominant parameter determining the biochar adsorption capacity. Wood doping with FeSO4 resulted in biochars with higher adsorption capacity due to the formation of mesopores and Fe clusters within these mesopores that could likely enhance the adsorption capacity. In the case of naphthalene cracking, biochars produced under reactive atmosphere (G1) with untreated wood and H2O-washed wood showed the highest naphthalene conversion. In this case, the specific surface area was not the most relevant parameter determining the biochars performance. Wood doping with KCl had a negative impact on naphthalene cracking, while wood doping with FeSO4 impacted positively when the biochar was produced in N2 atmosphere, but negatively when produced in reactive atmosphere (G1), likely due to the oxidation state of Fe. Biochars from agricultural residues and woody biochars, produced under the same conditions, performed similarly.

Selective Hydrogenation of Naphthalene to Produce Tetralin over a Ni/S950 Catalyst under Mild Conditions

Tetralin is an essential chemical that can be generated by the partial hydrogenation of naphthalene. However, it is a challenge to design a catalyst with high efficiency, low-temperature activity, high tetralin selectivity, and a low cost to produce tetralin. A Ni/S950 catalyst with well-dispersed metal particles and high catalytic activity was prepared with an ion-exchange method. A complete conversion of naphthalene and a high tetralin yield of 95.6% were achieved over the Ni/S950 catalyst under 200 °C, 2 h, and 2 MPa H2. Compared with Co/S950 and Cu/S950, both the hydrogenation activity and the selectivity of tetralin over Ni/S950 are much higher due to its well-dispersed Ni particles with a smaller particle size of 6.8 nm and numerous active Ni0 sites.

Design and preparation of Pt@SSZ-13@β core-shell catalyst for hydrocracking of naphthalene

A Pt@SSZ-13@β core-shell catalyst is designed and successfully prepared for investigating the effects of spillover hydrogenation on hydrocracking of naphthalene. The Pt NPs encapsulated in SSZ-13 cages are inaccessible to naphthalene due to its lager size than the pore size of SSZ-13. Thus, hydrogenation functional over Pt@SSZ-13@β is mainly realized via spillover hydrogenation. Pt@SSZ-13@β exhibits higher selectivity to the desired BTX and less naphthenic products than (Pt/SSZ-13)@β and Pt/(SSZ-13@β) at above 90 % naphthalene conversion. These results indicate the hydrogenation modes resulting from the location of the supported Pt NPs in core-structure catalysts can affect the metal-acid balance, and the spillover hydrogenation can effectively suppress the deep hydrogenation of tetralin in hydrocracking of naphthalene, thereby changing the reaction path and improving the selectivity of BTX. In addition, Pt@SSZ-13@β shows a better sulfur-tolerant ability than Pt/(SSZ-13@β). This work provides a new synthetic strategy for preparing zeolite-based bifunctional catalyst.

Synthesis of Multi-butylnaphthalene Base Oils Catalyzed by Trifluoromethanesulfonic Acid and Its Lubricating Properties

Alkylnaphthalene as base oils are widely applied in the production of high-performance lubricating oils. Here, we report the synthesis of multi-butylnaphthalenes by alkylation of naphthalene and n-butene with trifluoromethanesulfonic acid as catalyst. Trifluoromethanesulfonic acid exhibited excellent catalytic performance with naphthalene conversion, as high as 98.5%, and the multi-butylnaphthalenes selectivity of 98.8% under optimum conditions. To investigate the effects of the side-chain numbers on naphthalene on the lubrication performance, two kinds of alkylnaphthalenes were obtained by controlling catalyst dosage, denoted as MBN-1 (90.3% mono/di-butylnaphthalenes) and MBN-2 (98.2% tri/tetra/penta/hexa-butylnaphthalenes), respectively. The primary physiochemical properties of the synthetic oils were tested, and their tribological performance was evaluated. MBN-2, with more side chains on naphthalene, displayed more effective friction reduction and anti-wear properties than MBN-1 and the commercial alkyl naphthalene base oil AN5.