Liquid Catalyst Research Articles

Ultrasound‐assisted efficient aerobic oxidative coupling of thiols to disulfides with DiMIM‐CH3SO4 as a recyclable ionic liquid catalyst in water: A green approach

AbstractAn ultrasound‐assisted method with specific characteristics of green chemistry for aerobic oxidative coupling of thiols to disulfides is presented. In this method, a readily available ionic liquid catalyzed the aerobic oxidative coupling of thiols to disulfides in water as a green solvent under ultrasonic irradiation at room temperature. In this novel sonocatalysis/ionic liquid protocol, aromatic thiols having both electron‐donating and electron‐withdrawing substituents, alkyl thiols and cysteine, were cleanly converted to the corresponding disulfides in excellent yields. This methodology uses 1,3‐dimethyl imidazolium methyl sulfate (DiMIM‐CH3SO4) ionic liquid as a recyclable catalyst and aerobic oxygen as an oxidative agent. This protocol has the advantages of high yields, short reaction times, lower cost, environmentally friendly reaction media, easy isolation of products, convenient procedure and recoverability of catalyst.

Exploring the Synthetic and Antioxidant Potential of 1,2-Disubstituted Benzimidazoles Using [Et3NH][HSO4] Ionic Liquid Catalyst.

An [Et3NH][HSO4] ionic-liquid catalyzed, intermolecular C-N bond formation for 1,2-disubstituted benzimidazole synthesis was achieved by the reaction of OPD and substituted aldehydes at ambient reaction conditions. Operational simplicity, use of easily available substrate and reagents, good yields (74-95 %) in short reaction time (4-18 min), simple work-up, and column chromatographic free synthesis are the remarkable features of this new protocol. The applicability of [Et3NH][HSO4] ionic-liquid as a green and inexpensive catalyst with good recyclability and compatibility with a broad range of functional group having heteroatom, electron-withdrawing, and electron-releasing groups manifested the sustainability, eco-friendliness, and efficiency of the present methodology. Moreover, the antioxidant studies of the synthesized compounds using DPPH and ABTS assays were appealing and several synthesized compounds showed significant antioxidant activity.

Effect of adsorption-catalytic deformation and partial deactivation on the determination of the absolute activity of a liquid phase hydrogenation catalyst

Objectives. To take into account the change in the number of active sites during the adsorptioncatalytic deformation and deactivation of a catalyst surface by means of a catalytic poison when calculating the turnover frequency (TOF) of a hydrogenation catalyst.Methods. The activity was determined by a static method, using a titanium reactor having a volume of 400 mL, an experimental temperature controlled using a liquid thermostat with an accuracy of 0.5 K, with a paddle stirrer rotation speed of 3600 rpm and system hydrogen pressure equal to atmospheric. The consumption of hydrogen used to reduce the model compound was taken into account via the volumetric method. The heats of hydrogen adsorption were determined using a reaction calorimeter with an operating mode close to that of a chemical reactor. After measuring the specific surface area using low temperature nitrogen adsorption, the results were processed using Brunauer–Emmett–Teller theory approximations. Deactivation was carried out by introducing dosed amounts of catalytic poison into the system in titration mode.Results. A kinetic experiment for the reduction of a multiple carbon bond in a sodium maleate molecule using aqueous solutions of sodium hydroxide with additions of monohydric aliphatic alcohols as solvents under conditions of partial deactivation of the catalyst was carried out. The obtained values of heats of hydrogen adsorption on skeletal nickel in the course of the experiment are given. The described approach is used to calculate TOF values taking into account changes in the number of active surface sites during the course of a catalytic reaction and upon the introduction of a deactivating agent. A refined equation for the correct calculation of TOF is proposed along with its mathematical justification. The results of TOF calculations under various assumptions for a number of catalytic systems are shown.Conclusions. When calculating absolute activity values, a change in the number of active sites has a significant effect on the obtained values. The physical meaning of a number of constants in the proposed equation relates the activity of the catalyst to the distribution of hydrogen on its surface in terms of heats of adsorption.

The influence of air pollution control devices on gas organic pollutants emission from coal-fired power plants based on LCA

Air pollutants (e.g., NOx, SO2) emitted from coal-fired power plants in China have been effectively controlled by Air Pollution Control Devices (APCDs) since 1996. However, the gas organic pollutants (typically Volatile Organic Compounds (VOCs) and Polycyclic Aromatic Hydrocarbons (PAHs)) have been overlooked for a long time. In this study, based on the life cycle assessment method, the effect of APCDs (mainly Selective Catalytic Removal (SCR), Electrostatic Precipitator (ESP), Wet Flue Gas Desulfurization (WFGD), and Wet Electrostatic Precipitator (WESP)) on gas organic pollutants (without methane) from three typical coal-fired power plants in China has been evaluated in terms of direct emission removal and indirect emissions. Detecting the gas organic pollutants concentrations at the inlet and outlet of APCDs in these three cases, it is found that the total direct emission removal efficiency is up to more than 71.97%, with SCR’s contribution being the highest. However, the manufacture and equipping of APCDs will lead to indirect emission of gas organic pollutants. The result shows that the SCR system is also the main process that induces indirect emissions of gas organic pollutants, associated with the utilization of liquid ammonia and catalyst. Compared to the direct emission of gas organic pollutants, indirect gas organic pollutants emissions can not be ignored. The calculation of net emission removal and the degree of co-effects shows that APCDs can reduce gas organic pollutants, which results in reducing the photochemical ozone creation potential of 1.81E-06~5.93E-06kg(Ethene eq.)/MW·h and human toxicity potential of 2.51E-03~8.06E-03kg (DCB eq.)/MW·h.

EMIm][BH3CN] Ionic Liquid as an Efficient Catalyst for the Microwave- Assisted One-Pot Synthesis of Triaryl Imidazole Derivatives

Abstract: In this present investigation, efficient and general protocols for the synthesis of a series of imidazoles 4(a-p) derivatives have been developed by cyclocondensation of aromatic aldehydes, benzil and ammonium acetate in the existence of efficient [EMIm][BH3CN] ionic liquid catalyst under microwave condition in good to excellent yields (91-97%). The structures of the synthesized compounds have been confirmed by IR and NMR spectra. The significant features of this protocol are an uncomplicated workup process, rate enhancement with high yields, and efficient catalysts. It was concluded that [EMIm][BH3CN] is the finest catalyst under MW heating conditions.

Unravelling the Surface Oxidation-Induced Evolution of the Electronic Structure of Gallium.

Gallium is widely used in liquid metal catalyst fabrication, and its oxidized species is a well-known dielectric material. In the past decades, these two species have been well studied separately. However, the surface oxide layer-induced impact on the chemical and electronic structure of (liquid) gallium is still mostly unclear because of the extreme fast formation of thermodynamically stable surface Ga2O3. In this study, we used a combination of direct and inverse photoemission complemented by scanning electron microscopy to examine the surface properties of Ga and Ga oxide (on a SiOx/Si support) and the evolution of the surface structure upon stepwise oxidation and subsequent reduction at an elevated temperature. We find oxidation time-dependent self-limited formation of a substoichiometric Ga2O3-δ surface layer on the Ga nanoparticles. The valence band maximum (conduction band minimum) for this Ga2O3-δ is located at -3.8 (±0.1) eV [1.4 (±0.2) eV] with respect to the Fermi level, resulting in an electronic surface band gap of 5.2 (±0.2) eV. Upon annealing in ultrahigh vacuum conditions, the Ga2O3-δ surface layer can efficiently be removed when using temperatures of 600 °C and higher. This study reveals how the surface properties of Ga nanoparticles are influenced by stepwise oxidation-reduction, providing detailed insights that will benefit the optimization of this material class for different applications.

Efficient and Convenient Transformation of CO2 into α‑Alkylidene Cyclic Carbonates over Reusable and Heterogeneous Cu-MCM-41 Supported Ionic Liquid Catalyst

Efficient and Convenient Transformation of CO2 into α‑Alkylidene Cyclic Carbonates over Reusable and Heterogeneous Cu-MCM-41 Supported Ionic Liquid Catalyst

Magnetic ionic liquid catalyst functionalized with antimony (III) bromide for effective glycolysis of polyethylene terephthalate

In a previous study, we demonstrated the efficient depolymerization of polyethylene terephthalate (PET) through glycolysis using antimony (III) oxide, a commonly used catalyst in PET synthesis. In the present research, we introduce a novel approach involving the synthesis of a magnetic bifunctional ionic liquid, Fe3O4@PMIM.SbBr4, containing only 2.2 wt% of antimony. The aim is to reduce the required antimony dosage for the reaction and enable its facile recovery and reuse. By employing this catalyst in PET chemical recycling through glycolysis to generate bis (2-hydroxyethyl) terephthalate (BHET) monomer, we achieved 100% PET conversion with a 96.4% yield and selectivity for BHET. This outcome was obtained using a catalyst loading of 6.0 wt% at 200 °C and 0.6 bar in a high-pressure reactor. We explored the impact of catalyst loading on BHET yield and conducted a comparative assessment of the Fe3O4@PMIM.SbBr4 catalyst against antimony (III) bromide, and another synthesized unsupported antimony-containing ionic liquid. Our results revealed the superior catalytic activity of the magnetic ionic liquid catalyst in PET glycolysis. The utilization of this catalyst offers promising potential for PET glycolysis due to its effortless separation using an external magnet, ability to produce highly pure BHET, and recyclability for repetitive use.

Titanium Tetrachloride‐Based Ionic Liquids Immobilized on Mesoporous Fe‐MCM‐41 for the Heterogeneous Cooperative Synthesis of Dihydroquinazolinones

AbstractIn this study, we report a successful strategy for the generation of a type of multifunctional heterogeneous supported ionic liquids catalysts. The synthesized supported ionic liquids (Fe‐MCM‐41/IL) were used in the catalytic cyclocondensation of 2‐aminobenzamide and various ketones and aldehydes towards the efficient synthesis of the dihydroquinazolinones under green conditions. The influence of the different catalysts and reaction parameters on the catalytic behaviors were sufficiently investigated. The supported catalyst (2)Fe‐MCM‐41/IL(0.6) showed the optimal catalytic efficiency. A hot filtration experiment revealed that the reaction proceeded in a heterogeneous pathway. The catalytic activity of (2)Fe‐MCM‐41/IL(0.6) could be maintained efficiently after recycling up to five consecutive runs under the optimized reaction conditions. Merits of this meticulously designed protocol are the use of novel supported catalyst, easy work‐up process, feasibility and sustainability, indicating its potential industrial application prospect.

Self-regulation of electron density in metal centers for ionic liquid co-doped biochar catalysts in heterogeneous electro-Fenton-like process

The performance of the electrocatalyst depends on the adsorption energy of the reaction intermediates to the catalyst surface. However, the electron density of the metal centers plays an essential role in the adsorption energy. Therefore, trying to optimize the adsorption energy by adjusting the local electron density of metal centers is an important means to prepare highly active electrocatalysts, but how to controllably adjust the electron density of metal centers to remains a considerable challenge. Herein, we proposed a simple self-regulation strategy of electron density over metal active centers. The electron density of Cu sites was controllably tuned by adjusting the ions variety (B, N, and P) in ionic liquids. Experimental results and theoretical simulations revealed that in the optimal catalyst Cu-BN/C, the introduction of B decreased the electronic density of Cu centers and down-shifted the corresponding d-band center, thus achieving optimization of both adsorption and desorption of *O2 and *OOH. As a result, in the degradation of sulfamethoxazole, the rate constant (k) of Cu-BN/C reached 1.9 and 2.3 times than that of Cu-PN/C and Cu–N/C catalysts, respectively. This study provides a new insight for accurately adjusting the electron density of catalysts at the atomic level.

(Invited) Efficient Carbon Sulfonation Using Plasma in Contact with Dilute Sulfuric Acid

Heterogeneous catalysis is a promising technology in biomass valorization because of its high reactivity, easy post-separation, and great recyclability compared to homogeneous catalysis. Various functionalized catalytic materials have emerged as promising alternatives to the homogeneous liquid acid catalyst, such as carbon materials, metal–organic frameworks, and metal nanoparticles. Among them, carbon materials such as carbon nanotube, graphene oxide, carbon black, and so on have been investigated as catalysts for cellulose hydrolysis to produce glucose.Carbon materials show considerable catalytic activity by functionalization with active acidic groups including hydroxyl groups (-OH), carboxyl groups (-COOH), and sulfonic groups (-SO3H). Hydroxyl and carboxyl groups on the carbon catalysts act as connection center to access cellulose, where sulfonic group serves as the active site to cut off the linkage between glucose units in cellulose. So, the surface modification of carbon materials with these functional groups, namely, carbon sulfonation process, becomes the determining step to producing efficient carbon acid catalysts. Conventional methods for the carbon sulfonation are the hydrothermal and reflux method, in which hazardous chemicals are necessary, such as concentrated sulfuric acid (95–98%), chlorosulfonic acid, fuming sulfuric acid, or 4-benzenediazoniumsulfonate under elevated temperature for dozens of hours. As a green and effective carbon sulfonation process, we have utilized gas–liquid interfacial plasma (GLIP).In the GLIP process, plasma is generated between the tips of multi-needles and the surface of dilute sulfuric acid which contains carbon particles in N2/Ar gas mixture. The optimized catalyst synthesized from graphene nanoplatelets by the GLIP process achieved a conversion rate of 41.5% with high glucose selectivity of 84.3%, which is superior to performance of catalysts synthesized by the hydrothermal method. The concentration of sulfuric acid, reaction temperature, and reaction time for the GLIP process were 1 M, 40℃, and 0.75 h, respectively while those of the hydrothermal method were 18 M, 200℃, and 24 h, respectively. Thus, the GLIP process is less hazardous and more efficient. Significantly, the catalyst synthesized by the GLIP process also exhibited superior recyclability of 95.9% in 3 times cycle tests for cellulose hydrolysis.Recently, we have investigated the mechanism of carbon sulfonation in GLIP processes. Active species produced near the gas–liquid interface such as ·OH, SO3, and HOSO2· probably play important roles in carbon sulfonation. We are trying to observe gas-phase active species by Fourier transform infrared spectroscopy and quadrupole mass spectrometer, and liquid-phase active species by electron spin resonance spectroscopy.

Synthesis of n-butanol-rich C3+ alcohols by direct CO2 hydrogenation over a stable Cu–Co tandem catalyst

The direct conversion of CO2 into liquid fuels and chemical heterogeneous catalysts is considered a promising route to mitigate global warming issues. However, the production of n-butanol-rich C3+ alcohol from CO2 remains a significant challenge. Herein, we demonstrate that a Cu-rich bimetallic Cu–Co catalyst can achieve an unprecedentedly high space-time yield (STYC3+OH) of 80.8 mg g−1 h−1. The decoration of Co nanoparticles onto the dendritic Cu substrate established a crucial balance between CHx and CH3O* and regulated C–C coupling, which is a prerequisite for C3+ alcohol synthesis. We provide new mechanistic insights into n-butanol synthesis involving the C–O bond dissociation of an acetaldehyde intermediate on the interfacial Cu–Co site and subsequent C–C bond formation on the Cu site. Furthermore, the Cu–Co catalyst exhibited exceptional stability up to 1000 h by effectively suppressing re-oxidation and carbon deposition. The Cu–Co catalyst has great potential for large-scale CO2 hydrogenation to C3+ alcohol owing to its high selectivity and remarkable stability.

A swarm of liquid metal microdroplets for recyclable catalysis with high spatial-temporal precision

Nanocatalysts have aroused broad interest due to their long-lasting water-remediation capability. However, conventional nanocatalysts based on noble-metal nanoparticles rely on passive solute diffusion. Therefore, demands for improvements in yields of desired products, reductions in the use of noble metals, and improvements in nanocatalyst recyclability by magnetic separation pose significant challenges to the passive nanocatalysts. Herein, we developed a general method for liquid metal microdroplets modification with noble metal nanoparticles (e.g., Au and Ag), resulting in microdroplets with exceptional catalytic properties to decompose organic pollutants. The LM-Fe@PDA@Au and LM-Fe@PDA@Ag catalysts were dynamically well assembled, and they moved according to predesigned trajectories under magnetic-field control. The liquid metal microdroplets, on the one hand, are microscale matrices for embedding the magnetic particles; on the other hand, are microscale carriers for the fixation of noble metal nanoparticles, to maintain the uniform segregation of the nanoparticles. Due to their excellent mobility and three-dimensional convection, the catalysts could conduct an on-the-fly catalysis with high spatial-temporal precision at preassigned locations. Compared to conventional passive nanocatalysts based on noble-metal nanoparticles, the liquid metal microdroplets catalysts, which were based on the active colloidal swarms, showed temporally and spatially enhanced catalytic activity and improved catalytic rate constants. The catalysts could be easily collected using a magnet, and their inner liquid metal microdroplets could be recycled by treating the catalysts with a base. The work is of potential industrial significance to enhance the catalytic efficiency and shorten the catalytic time during water remediation, with the precious inner components recyclable.

Polymer‐supported Quaternary Phosphonium Ionic Liquid Catalysts for Efficient Fixation of CO2 into Cyclic Carbonates

AbstractThe chemical conversion of CO2 into cyclic carbonate is an effective method for the resource utilization of CO2 and the production of cyclic carbonates. Herein, a series of polymer‐supported quaternary phosphonium ionic liquid catalysts with high grafting amount have been systematically designed and synthesized, and all catalysts could promote efficient fixation of CO2 into cyclic carbonate. According to the results of the experiment and simulation, it was found that the high catalytic activity was ascribed to the weak interaction energy of the anion and cation of the catalyst. Among them, PS−TPP−Cl, with lower interaction energy of 72.2 KJ/mol, showed better performance. Yet even after being recycled five times, its conversion of propylene oxide with little loss was still above 95 %. Furthermore, a possible cycloaddition mechanism for the synergetic effect of cation‐anion coordination has been proposed. This work will shed new light on the development of novel heterogeneous catalysts with promising properties for industrial applications.

Synthesis of novel Biginelli and Hantzsch products from biorenewable furfurals using 1,4‐diazabicyclo[2.2.2]octanium diacetate as a Brønsted acidic ionic liquid catalyst

Abstract3,4‐Dihydropyrimidin‐2(1H)‐ones (DHPMs) and 1,4‐dihydropyridines (DHPs) are well‐established classes of heterocyclic compounds with remarkable biological properties. Various protonated organic amines were screened as Brønsted acidic ionic liquid catalysts under the Biginelli and Hantzsch reaction conditions for synthesizing novel DHPMs and DHPs, respectively, starting from biorenewable furfurals. 1,4‐Diazabicyclo[2.2.2]octanium diacetate (DABCO‐DA) was found as an efficient catalyst for the organic solvent‐free synthesis of novel DHPMs and DHPs in excellent (>85 %) isolated yields. The process parameters (e. g., temperature, molar ratio of reagents, duration, and loading of acid catalyst) were optimized, and a general synthetic protocol for synthesizing DHPMs and DHPs from 5‐substituted‐2‐furaldehydes has been developed. The DABCO‐DA catalyst was successfully recovered from the reaction mixture and reused for four consecutive cycles.

Purification of archetypal soybean root suberin mostly comprising alka(e)noic acids using an ionic liquid catalyst.

Soybean (Glycine max) is an increasingly relevant crop due to its economic importance and also a model plant for the study of root symbiotic associations with nodule forming rhizobia. Plant polyesters mediate plant-microbe interactions with both pathogenic and beneficial microbes; suberin has been hypothesized to play a key role during the early steps of rhizobia attachment to the root. The downside is that suberin chemistry in soybean root is still scarcely studied. This study addresses this outstanding question by reporting a straightforward workflow for a speedy purification of suberin from soybean root and for its subsequent detailed chemical analysis. To purify suberin, cholinium hexanoate (an ionic liquid) was used as the catalyst. The ensuing suberin is highly esterified as observed by a precise Nuclear Magnetic Resonance quantification of each ester type, discriminating between primary and acylglycerol esters. Moreover, the composing hydrolysable monomers detected through GC-MS revealed that hexadecanoic acid is the most abundant monomer, similar to that reported before by others. Overall, this study highlights the adequacy of the ionic liquid catalyst for the isolation of suberin from soybean roots, where the polymer natural abundance is low, and builds new knowledge on the specificities of its chemistry; essential to better understand the biological roles of suberin in roots.

Acetalization of Alkyl Alcohols with Benzaldehyde over Cesium Phosphomolybdovanadate Salts

In this work, vanadium-substituted cesium phosphomolybdate salts with general formulae Cs3+nPMo12−nVnO40 (n = 0, 1, 2, and 3) were synthesized and evaluated in the acetalization of benzaldehyde with alkyl alcohols. All the catalysts were characterized through Raman, infrared, and ultraviolet–visible spectroscopies, powder X-ray diffraction patterns, isotherms of N2 desorption/adsorption, and measurements of acidity strength. The catalytic activity of cesium phosphomolybdovanadate salts was evaluated in the acetalization reactions of benzaldehyde with alkyl alcohols. Among the salts tested, the Cs4PMo11V1O40 was the most active and selective catalyst in the conversion of benzaldehyde to methyl benzyl acetal and benzoic acid, which was obtained without the use of an oxidant agent. The impact of the main reaction parameters on the conversion and selectivity was evaluated by varying the content of vanadium per heteropolyanion, catalyst load, temperature, and alkyl alcohols. The greatest activity of the Cs4PMo11V1O40 salt was assigned to the highest Brønsted acidity strength, as demonstrated by the acidity measurements and analysis of their surface properties. This solid catalyst has advantages over traditional liquid homogenous catalysts, such as low corrosiveness, a minimum generation of residues and effluents, and easy recovery/reuse. In addition, its synthesis route is easier and quicker than solid-supported catalysts and comprises a potential alternative route to synthesize acetals.

Hydrogen Production by Methane Pyrolysis in Molten Cu-Ni-Sn Alloys

Hydrogen is an essential vector for transitioning today’s energy system. As a fuel or reactant in critical industrial sectors such as transportation and metallurgy, H2 can diversify the energy mix and supply and provide an opportunity to mitigate greenhouse-gas emissions. The pyrolysis of methane in liquid catalysts represents a promising alternative to producing hydrogen, as its energy demand is comparable to steam methane reforming, and no CO2 is produced in the base reaction. In this work, methane pyrolysis experiments were conducted using a graphite crucible filled with liquid ternary Cu-Ni-Sn alloys at 1160.0 °C. A statistical design of experiments allowed the generation of a model equation that predicts the achievable conversion rates in the ranges of the experiments. Furthermore, the experimental results are evaluated considering densities as well as surface tensions and viscosities in the investigated system, calculated with Butler and KRP equations, respectively. The highest methane conversion rate of 40.15% was achieved utilizing a melt of pure copper. The findings show that a combination of high catalytic activity with a high density and a low viscosity and surface tension of the melt results in a higher hydrogen yield. Furthermore, the autocatalytic effect of pyrolysis carbon is measured.

Quality conversion of H2S into β-mercaptopropionic acid by CETSA-based ionic liquid

With respect to the detrimental hydrogen sulfide (H2S), a whole new range of hydrophilic ionic liquids (ILs) could conveniently catalyze into more widely needed chemical reagents. ILs could be beneficial to increase the solubility and ionization of H2S, resulting in the Michael addition reaction with acrylic acid to produce β-mercaptopropionic acid. In this study, four kinds of hydrophilic ILs were synthesized by using carboxyethiosuccinic acid (CETSA), which contains three carboxyl groups with different chemical properties, as anions and combined with basic cations. The effect of the structure and reaction conditions of ILs on the catalytic activity of the system was studied. The result showed that the CETSA-based ILs with N, N, N′, N' -tetramethyl-1, 6-hexamethylenediamine (TMHDA) as cation had the best catalytic effect. ILs catalyst can greatly improve the selectivity and yield of the target product in addition reaction, which could be used for eight times at least without a noticeable decrease in its activity and conversion. In the absence of H2S cylinders, the conversion of acrylic acid can reach 99.21%, and the selectivity and yield of mercaptopropionic acid can reach 92.57% and 91.84% with [TMHDAH]CETSA. The ILs was characterized by FTIR, 1H NMR, 13C NMR and MS in order to determine the structure of the ILs. The thermal stability of ILs in the reaction system was observed by TG and DSC, and the ionization of ILs in solvent was measured by pH meter.

Selective preparation of jet fuels from low carbon alcohols and ABE at atmospheric pressure

Developing efficient jet-fuel synthesis route using bio-based low carbon alcohols or ABE (acetone/butanol/ethanol) is of great significance in reducing carbon emission. The objective of this work is to demonstrate that jet fuels can be selectively prepared from ABE and low carbon alcohols under atmospheric pressure condition. This controllable synthetic strategy was based on the two-step processes: selective dehydration of ABE (or low-carbon alcohols) into light olefins over the Ce@Fe@SAPO-34 catalyst and olefin polymerization into jet fuels over the ionic liquid catalyst ([bmim]Cl–2AlCl3). The optimizations of the catalysts and reaction conditions were investigated in detail. Under the atmospheric pressure, high ABE conversion (89.3%) and high jet fuel yield (71.5%) were achieved through coupling the two-step process.