In this work, a new ZnO/CoNiO₂/CoO/C metal oxides composite is prepared by cost-effective hydrothermal method coupled with annealing process under N₂ atmosphere. Notably, the oxidation-defect annealing environment is conducive to both morphology and component of the composite, which flower-like ZnO/CoNiO₂/CoO/C is obtained. Benefited from good chemical stability of ZnO, high energy capacity of CoNiO₂ and CoO and good conductivity of C, the as-prepared sample shows promising electrochemical behavior, including the specific capacity of 1435 C·g^-1 at 1 A·g^-1, capacity retention of 87.3% at 20 A·g^-1, and cycling stability of 90.5% for 3000 cycles at 5 A·g^-1, respectively. Furthermore, the prepared ZnO/CoNiO₂/CoO/C/NF//AC aqueous hybrid supercapacitors device delivers the best specific energy of 55.9 W·h·kg^-1 at 850 W·kg^-1. The results reflect that the as-prepared ZnO/CoNiO₂/CoO/C microflowers are considered as high performance electrode materials for supercapacitor, and the strategy mentioned in this paper is benefit to prepare mixed metal oxides composite for energy conversion and storage.

The synthesis of methacrylic acid from biomass-derived itaconic acid is a green route, for it can get rid of the dependence on fossil resource. In order to solve the problems on this route such as use of a preciousmetal catalyst and a corrosive homogeneous alkali, we prepared a series of hydroxyapatite catalysts by an ionic liquid-assisted hydrothermal method and evaluated their catalytic performance. The results showed that the ionic liquid [Bmim]BF₄ can affect the crystal growth of hydroxyapatite, provide fluoride ion for fluorination of hydroxyapatite, and adjust the surface acidity and basicity, morphology, textural properties, crystallinity, and composition of hydroxyapatite. The [Bmim]BF₄ dosage and hydrothermal temperature can affect the fluoride ion concentration in the hydrothermal system, thus changing the degree of fluoridation of hydroxyapatite. High fluoride-ion concentration can lead to the formation of CaF₂ and thus significantly decrease the catalytic performance of hydroxyapatite. The hydrothermal time mainly affects the growth of hydroxyapatite crystals on the c axis, leading to different catalytic performance. The suitable conditions for the preparation of this fluoridized hydroxyapatite are as follows: a mass ratio of [Bmim]BF₄ to calcium salt =≥0.2:1, a hydrothermal time of 12 h, and a hydrothermal temperature of 130℃. A maximal methacrylic acid yield of 54.7% was obtained using the fluoridized hydroxyapatite under relatively mild reaction conditions (250℃ and 2 MPa of N₂) in the absence of a precious-metal catalyst and a corrosive homogeneous alkali.

1-hexene aromatization is a promising technology to convert excess olefin in fluid catalytic cracking (FCC) gasoline to high-value benzene (B), toluene (T), and xylene. Besides, the increasing market demand of xylene has put forward higher requirements for new generation of catalyst. For increasing xylene yield in 1-hexene aromatization, the effect of mesopore structure and spatial distribution on product distribution and Zn loading was studied. Catalysts with different mesopore spatial distribution were prepared by post-treatment of parent HZSM-5 zeolite, including NaOH treatment, tetra-propylammonium hydroxide (TPAOH) treatment, and recrystallization. It was found the evenly distributed mesopore mainly prolongs the catalyst lifetime by enhancing diffusion properties but reduces the aromatics selectivity, as a result of damage of micropores close to the catalyst surface. While the selectivity of high-value xylene can be highly promoted when the mesopore is mainly distributed interior the catalyst. Besides, the state of loaded Zn was also affected by mesopores spatial distribution. On the optimized catalyst, the xylene selectivity was enhanced by 12.4% compared with conventional Zn-loaded parent HZSM-5 catalyst at conversion over 99%. It was attributed to the synergy effect of mesopores spatial distribution and optimized acid properties. This work reveals the role of mesopores in different spatial positions of 1- hexene aromatization catalysts in the reaction process and the influence on metal distribution, as well as their synergistic effect two on the improvement of xylene selectivity, which can improve our understanding of catalyst pore structure and be helpful for the rational design of high-efficient catalyst.

A series of adsorbent materials (WPU-HA_x-y) with a three-dimensional porous structure, green sustainability, and excellent performance were prepared and evaluated for the removal of methylene blue using nontoxic and environmentally friendly waterborne polyurethane as the matrix material and humic acid, a biomass material, as the functional material. The newly synthesized adsorbents were characterized by infrared spectroscopy, scanning electron microscopy, specific surface area, and thermogravimetric. The effects of contact time (0e8 h), starting concentration (10e100 mg·L^-1), pH (3e11), solution temperature (30-60 ℃), and coexisting ions (Ca²⁺, Na⁺, K⁺, Mg²⁺) on the performance were investigated. Pseudo-first-order, pseudo-second-order, elovich, and intra-particle diffusion models were used to analyze the adsorption kinetics; the Langmuir, Freundlich, Temkin, and DubineRadushkovich adsorption isotherms were evaluated; and the adsorption behavior of the adsorbent materials was found to be more appropriate for the pseudo-second-order model for chemical pollutant removal than the Langmuir model, which depends on monolayer adsorption. WPU-HA₂-3 stood out with a maximum adsorption capacity of 813.0081 mg·g^-1 fitted to the pseudo-second-order and 309.2832 mg·g^-1 fitted to the Langmuir model, showing superior adsorption performance and regenerability.

High-energy-density fuels are important for volume-limited aerospace vehicles, but the increase in fuel energy density always leads to poor cryogenic performance. Herein, we investigated the transposed Paternò-Büchi reaction of biomass cyclic ketone and cyclic alkene to synthesize a new kind of alkyl-substituted polycyclic hydrocarbon fuel with high energy density and good cryogenic performance. The triplet-energy-quenching results and phosphorescent emission spectra reveal the sensitization mechanism of the reaction, including photosensitizer excitation, triplettriplet energy transfer, cyclization, and relaxation, and the possible reaction path was revealed by the density functional theory (DFT) calculations. The reaction conditions of photosensitizer type and addition, molar ratio of substrates, reaction temperature, and incident light intensity were optimized, with the target product yield achieving 65.5%. Moreover, the reaction dynamics of the reaction rate versus the light intensity are established. After the hydrogenation-deoxygenation reaction, three fuels with a high density of≥0.864-0.938 g·ml^-1 and a low freezing point of < 55 ℃ are obtained. This work provides a benign and effective approach to synthesize high-performance fuels.

As a natural organic polymer, xanthan gum (XG) can alleviate the plastic deformation of gel ink under strong stress and realize the reasonable regulation of the rheological properties of gel ink. However, as the double-helix structure connected by hydrogen bonds cannot resist the mechanical environment of strong stress, XG shows poor shear resistance. In this study, a polymer gel with interpenetrating polymer network structure was prepared by esterifying XG, taking polystyrene maleic anhydride (SMA) as the modifier. In addition to retaining the excellent rheological properties of XG, the generated polymer gel also exhibited high shear resistance. The optimal addition amount of the esterification reaction modifier was determined as m_XG: m_SMA = 5:3 according to the gel ink standard. With this amount, the viscosity of the modified xanthan gum (SXG) gel increased to 1578.8 mPa·s and 100.7 mPa·s at shear rates of 4 s^-1 and 383 s^-1, respectively, and the shear resistance increased more than 2 times compared to the unmodified one. It is because of the ester bond formed by esterification that the reaction strengthens the interaction between molecular segments, enabling the new gel to resist to strong mechanical stress. The new polymer gel studied in this paper and the proposed mechanism of action provide new insights for the development of high-end gel ink and also provide theoretical support for the study of rheological properties of non-Newtonian fluids.

The sluggish redox kinetics of polysulfides in lithiumesulfur (LieS) batteries are a significant obstacle to their widespread adoption as energy storage devices. However, recent studies have shown that tungsten oxide (WO₃) can facilitate the conversion kinetics of polysulfides in LieS batteries. Herein, we fabricated host materials for sulfur using nitrogen-doped carbon nanotubes (N-CNTs) and WO₃. We used low-cost components and simple procedures to overcome the poor electrical conductivity that is a disadvantage of metal oxides. The composites of WO₃ and N-CNTs (WO₃/N-CNTs) create a stable framework structure, fast ion diffusion channels, and a 3D electron transport network during electrochemical reaction processes. As a result, the WO₃/N-CNT-Li₂S₆ cathode demonstrates high initial capacity (1162 mA·h·g^-1 at≥0.5 C), excellent rate performance (618 mA·h·g^-1 at 5.5 C), and a low capacity decay rate (0.093% up to 600 cycles at 2 C). This work presents a novel approach for preparing tungsten oxide/carbon composite catalysts that facilitate the redox kinetics of polysulfide conversion.

For the reduction of bovine serum proteins from wastewater, a novel mixed matrix membrane was prepared by functionalizing the substrate material polyaryletherketone (PAEK), followed by carboxyl groups (C-SPAEKS), and then adding amino-functionalized UiO-66-NH₂ (Am-UiO-66-NH₂). Aminofunctionalization of UiO-66 was accomplished by melamine, followed by an amidation reaction to immobilize Am-UiO-66-NH₂, which was immobilized on the surface of the membrane as well as in the pore channels, which enhanced the hydrophilicity of the membrane surface while increasing the negative potential of the membrane surface. This nanoparticle-loaded ultrafiltration membrane has good permeation performance, with a pure water flux of up to 482.3 L·^m-2·^h-1 for C-SPAEKS/AmUiO-66-NH₂ and a retention rate of up to 98.7% for bovine serum albumin (BSA)-contaminated solutions. Meanwhile, after several hydrophilic modifications, the flux recovery of BSA contaminants by this series of membranes increased from 56.2% to 80.55% of pure membranes. The results of ultrafiltration flux time tests performed at room temperature showed that the series of ultrafiltration membranes remained relatively stable over a test time of 300 min. Thus, the newly developed mixed matrix membrane showed potential for high efficiency and stability in wastewater treatment containing bovine serum proteins.

To address the low conductivity and easy agglomeration of transition metal sulfide nanoparticles, FeCoS₄ nanoparticles embedded in S-doped hollow carbon (FeCoS₄@S-HC) composites were successfully fabricated through a combination of hydrothermal processes and sulfidation treatment. The unique bowlshaped FeCoS₄/S-HC composites exhibit excellent structural stability with a high specific surface area of 303.7 m²·g^-1 and a pore volume of≥0.93 cm³·g^-1. When applied as anode material for lithium-ion batteries, the FeCoS₄@S-HC anode exhibits efficient lithium storage with high reversible specific capacity (970.2 mA·h·g^-1 at 100 mA·g^-1) and enhanced cycling stability (574 mA·h·g^-1 at≥0.2 A·g^-1 after 350 cycles, a capacity retention of 84%). The excellent lithium storage is attributed to the fact that the bimetallic FeCoS₄ nanoparticles with abundant active sites can accelerate the electrochemical reaction kinetics, and the bowl-shaped S-HC structure can provide a stable mechanical structure to suppress volume expansion.

The use of fillers to enhance the corrosion protection of epoxy resins has been widely applied. In this work, cerium dioxide (CeO₂) and benzotriazole (BTA) were introduced into an epoxy resin to enhance the corrosion resistance of Q235 carbon steel. Scanning electron microscopy results indicated that the CeO₂ grains were rod-like and ellipsoidal in shape, and the distribution pattern of BTA was analyzed by energy dispersive spectroscope. The dynamic potential polarization curve proved the excellent corrosion resistance of the composite epoxy resin with CeO₂ and BTA co-addition, and electrochemical impedance spectroscopy test analysis indicated the significantly enhanced long-term corrosion protection performance of the composite coating. And the optimal protective performance was provided by the coating containing≥0.3% (mass) CeO₂ and 20% (mass) BTA, which was attributed to the barrier performance of CeO₂ particles and the chemical barrier effect of BTA. The formation of corrosion products was analyzed using X-ray diffraction. In addition, the corrosion resistance mechanism of the coating was also discussed in detail.

The efficient separation and collection of ammonia (NH₃) during NH₃ synthesis process is essential to improve the economic efficiency and protect the environment. In this work, ethanolammonium hydrochloride (EtOHACl) and phenol (PhOH) were used to prepare a novel class of deep eutectic solvents (DESs) with multiple active sites and low viscosities. The NH₃ separation performance of EtOHACl + PhOH DESs was analyzed completely. It is figured out that the NH₃ absorption rates in EtOHACl + PhOH DESs are very fast. The NH₃ absorption capacities are very high and reach up to 5.52 and 10.74 mol·kg^-1 at 11.2 and 100.4 kPa under 298.2 K, respectively. In addition, the EtOHACl + PhOH DESs present highly selective absorption of NH₃ over N₂ and H₂ and good regenerative properties after seven cycles of absorption/desorption. The intrinsic separation mechanism of NH₃ by EtOHACl + PhOH DESs was further revealed by spectroscopic analysis and quantum chemistry calculations.

Cyanobacteria-based activated carbon (CBAC) was successfully prepared by pyrolysis-activation of Taihu cyanobacteria. When the impregnation ratio and activated temperature were 2 and 800 ℃, respectively, the optimal CBACs possessed an ultra-high specific surface (2178.90 m²·g^-1) and plenty of micro- and meso-pores, as well as a high pore volume (1.01 cm³·g^-1). Ascribed to ultra-high surface area,π-π interaction, electrostatic interaction, as well as hydrogen-bonding interactions, the CBACs displayed huge superiority in efficient dye removal. The saturated methylene blue adsorption capacity by CBACs could be as high as 1143.4 mg·g^-1, superior to that of other reported biomass-activated carbons. The adsorption was endothermic and modeled well by the pseudo-second-order kinetic, intra-particle diffusion, and Langmuir models. This work presented the effectiveness of Taihu cyanobacteria adsorbent ascribed to its super large specific surface area and high adsorption ability.

As a high-performance material with great application potential, the application of carbon nanotubes has been limited by their production volume. A distributor-less conical fluidized bed is the main equipment used in the industrial production of carbon nanotubes. To improve the production volume and product quality of carbon nanotubes, the study of fluidized-bed-diameter scaling is important. Three different diameters of distributor-less conical fluidized beds were established, and then the particle behavior and bubble characteristics of carbon nanotube clusters at these bed diameters were investigated. Time-series and wavelet analysis methods were used to analyze the pressure-fluctuation signals inside the fluidized beds. Results showed that the distributor-less design caused the airflow to break through the middle of the bed, which did not change with the change in bed diameter. The powder-bridging phenomenon of carbon nanotube clusters in a 100-mm-diameter fluidized bed was related to the special microstructure of carbon nanotube clusters. The frequency of pressure fluctuations in the bed decreased nonlinearly with increasing bed diameter. This study can guide the design and scale-up of distributor-less conical fluidized beds, especially for the scale-up of carbon nanotube production equipment, which can contribute to the improvement of carbon nanotubes’ capacity and quality in industrial production.

Carbon emission reduction and clean energy development are urgent demands for mankind in the coming decades. Exploring an efficient CO₂ storage method can significantly reduce CO₂ emissions in the short term. In this study, we attempted to construct sediment samples with different residual CH₄ hydrate amounts and reservoir conditions, and then investigate the potentials of both CO₂ storage and enhanced CH₄ recovery in depleted gas hydrate deposits in the permafrost and ocean zones, respectively. The results demonstrate that CO₂ hydrate formation rate can be significantly improved due to the presence of residual hydrate seeds; However, excessive residual hydrates in turn lead to the decrease in CO₂ storage efficiency. Affected by the T-P conditions of the reservoir, the storage amount of liquid CO₂ can reach 8 times that of gaseous CO₂, and CO₂ stored in hydrate form reaches 2-4 times. Additionally, we noticed two other advantages of this method. One is that CO₂ injection can enhance CH₄ recovery rate and increases CH₄ recovery by 10%-20%. The second is that hydrate saturation in the reservoir can be restored to 20%-40%, which means that the solid volume of the reservoir avoids serious shrinkage. Obviously, this is crucial for protecting the goaf stability. In summary, this approach is greatly promising for high-efficient CO₂ storage and safe exploitation of gas hydrate.

This work investigated the pyrolysis reaction of waste resin in a fluidized bed reactor. It was found that the pyrolysis-generated ash would adhere to the surface of ceramic particles, causing particle agglomeration and defluidization. Adding kaolin could effectively inhibit the particle agglomeration during the fluidized pyrolysis reaction through physical isolation and chemical reaction. On the one hand, kaolin could form a coating layer on the surface of ceramic particles to prevent the adhesion of organic ash generated by the pyrolysis of resin. On the other hand, when a sufficient amount of kaolin (≥0.2% (mass)) was added, the activated kaolin could fully contact with the Na⁺ ions generated by the pyrolysis of resin and react to form a high-melting aluminosilicate mineral (nepheline), which could reduce the formation of low-melting-point sodium sulfate and thereby avoid the agglomeration of ceramic particles.

To date, the primary industrial carbon capture approach is still absorption using aqueous solutions of alkanolamines. Here, to pursue a substitute for the amine-based approach to improve the CO₂ capture efficiency and decrease the energy cost further, we report a new carbon capture approach using a 2-methylimidazole (mIm) aqueous solution. The properties and sorption behaviors of this approach have been experimentally investigated. The results show that the mIm solution has higher CO₂ absorption capacity under relatively higher equilibrium pressure (>130 kPa) and lower desorption heat than the methyldiethanolamine solution. 91.6% sorption capacity of mIm solution can be recovered at 353.15 K and 80 kPa. The selectivity for CO₂/N₂ and CO₂/CH₄ can reach an exceptional 7609 and 4324, respectively. Furthermore, the pilot-scale tests were also performed, and the results demonstrate that more than 98% of CO₂ in the feed gas could be removed and cyclic absorption capacity can reach 1 mol·L^-1. This work indicates that mIm is an excellent alternative to alkanolamines for carbon capture in the industry.

High concentrations of copper ions (Cu(II)) in water will pose health risks to humans and the ecological environment. Therefore, this study aims to utilize ultrasonic-cured modified municipal solid waste incineration (MSWI) fly ash for Cu(II) adsorption to achieve the purpose of “treating waste by waste.” The effects of pH, adsorption time, initial concentration, and temperature on the modified MSWI fly ash's adsorption efficiency were systematically studied in this article. The adsorption performance of the modified MSWI fly ash can be enhanced by the ultrasonic modification. At pH = 2, 3 and 4, the adsorption capacity of the modified MSWI fly ash for Cu(II) increased by 2.7, 1.9 and 1.2 times, respectively. Furthermore, it was suggested that the adsorption process of the modified MSWI fly ash can be better simulated by the pseudo-second-order kinetic model, with a maximum adsorption capacity calculated by the Langmuir model of 24.196 mg·g^-1. Additionally, the adsorption process is spontaneous, endothermic, and chemisorption-dominated from the thermodynamic studies (∆H and ∆S > 0, ∆G < 0). Finally, the enhanced adsorption performance of the modified MSWI fly ash for Cu(II) may be attributed to electrostatic interaction and chelation effects.

Two catalysts, nano-sized cobalt-metal-organic framework (Co-MOF) and nickel (Ni)-MOF, were successfully prepared by the modification method. Tetralin (C₁₀H₁₂) was used as the hydrogen donor for the catalytic cracking and hydrogenation modification study of the dehydrated crude oil from the Shengli Oilfield. The optimal reaction conditions were determined through orthogonal experiments, and the components of the crude oil and modified oil samples were analyzed. The results revealed that the nanoMOF catalysts were successfully prepared and exhibited high catalytic activity. They could catalyze the cracking of large molecules in heavy oil at mild temperatures (<300 ℃), leading to the decomposition of the hydrogen donor. When the mass fraction of the catalyst was≥0.2%, the mass fraction of the hydrogen donor was 1%, and the reaction temperature was 280 ℃, the Ni-MOF showed the best catalytic viscosity reduction effect. It could reduce the viscosity of heavy oil at 50 ℃ from 15761.9 mPa·s to 1266.2 mPa·s, with a viscosity reduction rate of 91.97%. The modification effect of Co-MOF was the next best, which could reduce the viscosity of heavy oil to 2500.1 mPa·s with a viscosity reduction rate of 84.14%. Molecular dynamics simulations revealed a strong interaction force between the MOF surface and asphaltene molecules. In the process of heavy-oil catalytic hydrogenation, the nano-MOF catalyst exhibited high catalytic activity. On the one hand, the empty d orbitals outside the metal atoms in the catalyst could polarize the carbon atoms in the organic matter, accelerating the breaking of long chains. On the other hand, the metal atoms in the catalyst could bond with the carbon σ bonds, breaking the carbon ecarbon bonds. This disrupted the structure of the recombined components in the crude oil, irreversibly reducing the viscosity of the heavy oil and improving its fluidity.

In-site soil flushing and aeration are the typical synergetic remediation technology for contaminated sites. The surfactant present in flushing solutions is bound to affect the aeration efficiency. The purpose of this study is to evaluate the effect of surfactant frequently used in soil flushing on the oxygen mass transfer in micro-nano-bubble (MNB) aeration system. Firstly, bio-surfactants and chemical surfactants were used to investigate their effects on Sauter mean diameter of bubble (d_BS), gas holdup (ε), volumetric mass-transfer coefficient (k_La) and liquid-side mass-transfer coefficient (k_L) in the MNB aeration system. Then, based upon the experimental results, the Sardeing's and Frössling's models were modified to describe the effect of surfactant on k_L in the MNB aeration. The results showed that, for the twenty aqueous surfactant solutions, with the increase in surfactant concentration, the value of d_BS, k_La and k_L decreased, while the value of ε and gas-liquid interfacial area (a) increased. These phenomena were mainly attributed to the synergistic effects of immobile bubble surface and the suppression of coalescence in the surfactant solutions. In addition, with the presence of electric charge, MNBs in anionic surfactant solutions were smaller and higher in number than in non-ionic surfactant solutions. Furthermore, the accumulation of surfactant on the gas-liquid interface was more conspicuous for small MNB, so the reduction of k_L in anionic surfactant solutions was larger than that in non-ionic surfactant solutions. Besides, the modified Frössling's model predicted the effect of surfactant onk_L in MNB aeration system with reasonable accuracy.

Wet flue gas desulphurization technology is widely used in the industrial process for its capability of efficient pollution removal. The desulphurization control system, however, is subjected to complex reaction mechanisms and severe disturbances, which make for it difficult to achieve certain practically relevant control goals including emission and economic performances as well as system robustness. To address these challenges, a new robust control scheme based on uncertainty and disturbance estimator (UDE) and model predictive control (MPC) is proposed in this paper. The UDE is used to estimate and dynamically compensate acting disturbances, whereas MPC is deployed for optimal feedback regulation of the resultant dynamics. By viewing the system nonlinearities and unknown dynamics as disturbances, the proposed control framework allows to locally treat the considered nonlinear plant as a linear one. The obtained simulation results confirm that the utilization of UDE makes the tracking error negligibly small, even in the presence of unmodeled dynamics. In the conducted comparison study, the introduced control scheme outperforms both the standard MPC and PID (proportional-integral-derivative) control strategies in terms of transient performance and robustness. Furthermore, the results reveal that a lowpass-filter time constant has a significant effect on the robustness and the convergence range of the tracking error.

It is of vital significance to investigate mass transfer enhancements for chemical engineering processes. This work focuses on investigating the coupling influence of embedding wire mesh and adding solid particles on bubble motion and gas-liquid mass transfer process in a bubble column. Particle image velocimetry (PIV) technology was employed to analyze the flow field and bubble motion behavior, and dynamic oxygen absorption technology was used to measure the gas-liquid volumetric mass transfer coefficient (k_La). The effect of embedding wire mesh, adding solid particles, and wire mesh coupling solid particles on the flow characteristic and k_La were analyzed and compared. The results show that the gas eliquid interface area increases by 33%-72% when using the wire mesh coupling solid particles strategy compared to the gas-liquid two-phase flow, which is superior to the other two strengthening methods. Compared with the system without reinforcement, k_La in the bubble column increased by≥0.5-1.8 times with wire mesh coupling solid particles method, which is higher than the sum of k_La increases with inserting wire mesh and adding particles, and the coupling reinforcement mechanism for affecting gas eliquid mass transfer process was discussed to provide a new idea for enhancing gas-liquid mass transfer.

Natural gas hydrate is an energy resource for methane that has a carbon quantity twice more than all traditional fossil fuels combined. However, their practical application in the field has been limited due to the challenges of long-term preparation, high costs and associated risks. Experimental studies, on the other hand, offer a safe and cost-effective means of exploring the mechanisms of hydrate dissociation and optimizing exploitation conditions. Gas hydrate decomposition is a complicated process along with intrinsic kinetics, mass transfer and heat transfer, which are the influencing factors for hydrate decomposition rate. The identification of the rate-limiting factor for hydrate dissociation during depressurization varies with the scale of the reservoir, making it challenging to extrapolate findings from laboratory experiments to the actual exploitation. This review aims to summarize current knowledge of investigations on hydrate decomposition on the subject of the research scale (core scale, middle scale, large scale and field tests) and to analyze determining factors for decomposition rate, considering the various research scales and their associated influencing factors.

Ce-encapsulated Beta zeolite was synthesized by a one-pot hydrothermal method with citric acid complexing Ce in the absence of Na species. Additional citric acid can effectively prevent the deposition of Ce species during the hydrothermal synthesis of zeolites, leading to uniform distribution of Ce cluster in the framework of Beta zeolites. Moreover, the sodium-free synthesis system resulted that the Brønsted acid sites were mainly located on the straight channels and external surface of Beta zeolites, improving the utilization of Brønsted acid sites. In addition, Ce encapsulated Beta zeolites showed enhanced activity and robust stability in the alkylation of benzene with 1-dodecene based on the synergistic effect between Ce species and Brønsted acid sites, which pave the way for its practical application in the production of alkylbenzene.

The addition of dispersed-phase nanoparticles in the liquid phase can enhance the gas-liquid transfer process as the suspended nanoparticles affect the transfer process inside the fluid through microdisturbance or micro-convection effects. In this article, a high-speed digital camera was used to visualize the bubble behavior of CO₂ in pure water and nanofluids to examine the effects of CO₂ gas flow rate, nanoparticle solid content and type on the bubble behavior in the fluids. The CO₂ absorption performance in three water-based nanofluids were compared in a bubbler. And the mass transfer characteristics during CO₂ bubble absorption and the reasons for the enhanced gas-liquid mass transfer effect of nanoparticles were analyzed. The results showed that the presence of nanoparticles affected the formation process of bubbles in the fluid, shortened the bubble detachment time, reduced the detachment diameter, effectively increased the gas-liquid contact area, and improved the bubbles detachment frequency. The system with MCM-41 corresponded to a higher overall mass transfer coefficient. Uncalined MCM-41 contained surfactant that enhanced foaming behavior in water. This prevented the transfer of CO₂ to some extent, and the CO₂ absorption by uncalined MCM-41/H₂O was 5.34% higher than that by pure water. Compared with SiO₂ nanoparticles with the same particle size and the same composition, MCM-41 had a higher adsorption capacity and better hydrophilicity due to its larger specific surface area and rich porous structure, which was more favorable to accelerate the collision between nanoparticles and CO₂ bubbles to cause micro-convection. Under the condition of≥0.1% (mass) solid content, the enhancement of CO₂ absorption process by MCM-41 nanoparticles was more significant and improved by 16.9% compared with pure water.

Alkane-based biodiesel is considered the next generation of biodiesel owing to its potential environmental benefits and the fact that it exhibits much higher specific caloric values than traditional biodiesel. However, the formidable obstacle impeding the commercialization of this cutting-edge fuel alternative lies in the cost associated with its production. In this study, an engineered strain Escherichia coli (E. coli) showcasing harmonized coexpression of a lipase (from Thermomyces lanuginosus lipase, TLL) and a fatty acid photodecarboxylase (from Chlorella variabilis, CvFAP) was first constructed to transform triglycerides into alkanes. The potential of E. coli BL21 (DE3)/pRSFDuet-1-TLL-CvFAP for alkane synthesis was evaluated with tripalmitin as a model substrate under various process conditions. Following a comprehensive examination of the reaction parameters, the scope of the biotransformation was expanded to ‘real’ substrates (vegetable oils). The results showed that bioderived oils can be transformed into alkanes with high yields (0.80-10.20 mmol·L^-1) under mild conditions (35 ℃, pH 8.0, and 36 h) and blue light illumination. The selected processes were performed on an increased lab scale (up to 100 ml) with up to 24.77 mmol·L^-1 tripalmitin, leading to a yield of 18.89 mmol·L^-1 pentadecane. With the employment of a method for efficiently producing alkanes under mild conditions and a simple procedure to isolate alkanes from the reaction system, the utilization of sustainable biomass as a fundamental feedstock emerges as the primary solution to lower the cost of alkane-based biodiesel. Thus, this study proposes a readily implementable and highly effective approach for alkane-based biodiesel production.

Compared to reforming reactions using hydrocarbons, ethanol steam reforming (ESR) is a sustainable alternative for hydrogen (H₂) production since ethanol can be produced sustainably using biomass. This work explores the catalyst design strategies for preparing the Ni supported on ZSM-5 zeolite catalysts to promote ESR. Specifically, two-dimensional ZSM-5 nanosheet and conventional ZSM-5 crystal were used as the catalyst carriers and two synthesis strategies, i.e., in situ encapsulation and wet impregnation method, were employed to prepare the catalysts. Based on the comparative characterization of the catalysts and comparative catalytic assessments, it was found that the combination of the in situ encapsulation synthesis and the ZSM-5 nanosheet carrier was the effective strategy to develop catalysts for promoting H₂ production via ESR due to the improved mass transfer (through the 2-D structure of ZSM-5 nanosheet) and formation of confined small Ni nanoparticles (resulted via the in situ encapsulation synthesis). In addition, the resulting ZSM-5 nanosheet supported Ni catalyst also showed high Ni dispersion and high accessibility to Ni sites by the reactants, being able to improve the activity and stability of catalysts and suppress metal sintering and coking during ESR at high reaction temperatures. Thus, the Ni supported on ZSM-5 nanosheet catalyst prepared by encapsulation showed the stable performance with ~88% ethanol conversion and ~65% H₂ yield achieved during a 48-h longevity test at 550 ℃.

For the application of carbon capture by membrane process, it is crucial to develop a highly permeable CO₂-selective membrane. In this work, we reported an ultra-thin polyether-block-amide (Pebax) mixedmatrix membranes (MMMs) incorporated by graphene oxide (GO), in which the interlayer channels were regulated to optimize the CO₂/N₂ separation performance. Various membrane preparation conditions were systematically investigated on the influence of the membrane structure and separation performance, including the lateral size of GO nanosheets, GO loading, thermal reduction temperature, and time. The results demonstrated that the precisely regulated interlayer channel of GO nanosheets can rapidly provide CO₂-selective transport channels due to the synergetic effects of size sieving and preferential adsorption. The GO/Pebax ultra-thin MMMs exhibited CO₂/N₂ selectivity of 72 and CO₂ permeance of 400 GPU (1 GPU = 10^-6 cm³(STP)·cm^-2·s^-1·cmHg^-1), providing a promising candidate for CO₂ capture.

Zinc (Zn)-air batteries are widely used in secondary battery research owing to their high theoretical energy density, good electrochemical reversibility, stable discharge performance, and low cost of the anode active material Zn. However, the Zn anode also leads to many challenges, including dendrite growth, deformation, and hydrogen precipitation self-corrosion. In this context, Zn dendrite growth has a greater impact on the cycle lives. In this dissertation, a dendrite growth model for a Zn-air battery was established based on electrochemical phase field theory, and the effects of the charging time, anisotropy strength, and electrolyte temperature on the morphology and growth height of Zn dendrites were studied. A series of experiments was designed with different gradient influencing factors in subsequent experiments to verify the theoretical simulations, including elevated electrolyte temperatures, flowing electrolytes, and pulsed charging. The simulation results show that the growth of Zn dendrites is controlled mainly by diffusion and mass transfer processes, whereas the electrolyte temperature, flow rate, and interfacial energy anisotropy intensity are the main factors. The experimental results show that an optimal electrolyte temperature of 343.15 K, an optimal electrolyte flow rate of 40 ml·min^-1, and an effective pulse charging mode.

Flue gas and coal bed methane are two important sources of greenhouse gases. Pressure swing adsorption process has a wide range of application in the field of gas separation, and the selection of adsorbent is crucial. In this regard, in order to assess the better adsorbent for separating CO₂ from flue gas and CH₄ from coal bed methane, adsorption isotherms of CO₂, CH₄ and N₂ on activated carbon and carbon molecular sieve are measured at 303.15, 318.15 and 333.15 K, and up to 250 kPa. The experimental data fit better with Langmuir 2 compared to Langmuir 3 and Langmuir-Freundlich models, and Clausius-Clapeyron equation was used to calculate the isosteric heat. Both the order of the adsorbed amount and the adsorption heat on the two adsorbents are CO₂ > CH₄ > N₂. The adsorption kinetics are calculated by the pseudo-first kinetic model, and the order of adsorption rates on activated carbon is N₂ ≥ CH₄ > CO₂, while on carbon molecular sieve, it is CO₂ ≥ N₂ > CH₄. It is shown that relative molecular mass and adsorption heat are the primary effect on kinetics for activated carbon, while kinetic diameter is the main resistance factor for carbon molecular sieve. Moreover, the adsorption selectivity of CH₄/N₂ and CO₂/N₂ were estimated with the ideal adsorption solution theory, and carbon molecular sieve performed best at 318.15 K for both CO₂ and CH₄ separation. The study suggested that activated carbon is a better choice for separating flue gas and carbon molecular sieve can be a strong candidate for separating coal bed methane.

Catalytic synthesis of m-diethylbenzene (m-DEB) through alkylation of ethylbenzene (EB) may be a promising alternative route in comparison with traditional rectification of mixed DEB, for which the top priority is to develop efficient and stable heterogeneous catalysts. Here, the spherical nano-ZSM-5 zeolite with abundant intergranular mesoporous is synthesized by the seed-mediated growth method for alkylation of EB with ethanol to produce m-DEB. The results show that the spherical nano-ZSM-5 zeolite exhibits better stability and higher alkylation activity at a lower temperature than those of commercial micropore ZSM-5. And then, the spherical nano-ZSM-5 is further modified by La₂O₃ through acid treatment followed by immersion method. The acid treatment causes nano-ZSM-5 to exhibit the increased pore size but decreased the acid sites, and subsequent La₂O₃ loading reintroduces the weak acid sites. As a result, the HNO₃eLa₂O₃-modified catalyst exhibits a slight increase in EB conversion and DEB yield in comparison with unmodified one, and meanwhile, it still maintains high m-DEB selectivity. The catalyst after acid treatment achieves higher catalytic stability besides maintaining the high alkylation activity of EB with ethanol. The present study on the spherical nano-HZSM-5 zeolite and its modification catalyst with excellent alkylation ability provides new insights into the production of m-DEB.