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In recent years, self-optimization strategies have been gradually utilized for the determination of optimal reaction conditions owing to their high convenience and independence from researchers' experience. However, most self-optimization algorithms still focus on homogeneous reactions or simple heterogeneous reactions. Investigations on complex heterogeneous gas–liquid–solid reactions are rare. Based on the Nelder–Mead simplex method and Bayesian optimization, this work proposes a reaction optimization framework for optimizing complex gas–liquid–solid reactions. Three gas–liquid–solid reactions including the hydrogenations of nitrobenzene, 3,4-dichloronitrobenzene, and 5-nitroisoquinoline are investigated, respectively. Reaction parameters (temperature, hydrogen pressure, liquid flow rate, and gas flow rate) are optimized. Compared with the traditional OVAT method, the proposed Bayesian based optimization algorithm exhibits remarkable performance with higher yields (0.998, 0.991 and 0.995, respectively) and computational efficiency.

Methods of coating Al2O3 on nickel micro-foam were compared and screened, aiming to overcome the capillary force and prepare the micro-foam monolithic catalyst coatings. The surface of micro-foam substrate was pretreated by a chemical etching method to improve the adhesion of the coatings on the substrate. The results showed that the slurry circulation at 162 ml·min-1 was evaluated as the optimal method. The pore size on the substrate surface can be controlled by changing the pretreatment conditions. An empirical correlation was also proposed, showing an excellent practicality for predicting the pore size. The adhesion of the coatings with substrate pretreatment was significantly better than that without substrate pretreatment. The minimum value of weight loss after ultrasonic vibration was 3.9%. This mainly attributes to the squeezing of Al2O3 particles in the pores of substrate surface. The coatings on nickel micro-foam are hopefully used in micropacked beds for catalytic reactions.

An automated flow platform based on a tube-in-tube contactor and micro-packed bed reactor is developed to measure the kinetics of gas–liquid–solid hydrogenation reactions. The liquid flowing in the inner tube of the tube-in-tube contactor is rapidly saturated to ensure a constant H2 concentration before entering the micro-packed bed, which transforms the gas–liquid–solid system into a liquid–solid system. A ramping strategy is adopted in which the continuously varied residence time and the corresponding conversion data are obtained in a single experiment. Two reactions including hydrogenation of α-methylstyrene and nitrobenzene are chosen to demonstrate the accuracy and efficiency of this automated platform. Varying the flow rate ramping shows that accurate kinetic determination requires a specific range of flow rate ramps. A kinetic curve of conversion versus residence time (more than ten thousand data points) can be obtained in a single experiment within 50 min. The kinetic parameters obtained with this strategy agree well with literature values. The automated flow platform with flow rate ramping enables accurate determination of gas–liquid–solid reaction kinetics with higher efficiency and lower reagent cost compared with other methods.

The hydrogenation of m-dinitrobenzene to m-phenylenediamine is a significant transformation for the synthesis of dyes and pigments in the fine chemical industry. Owing to the complexity of this reaction mechanism and negative effect of the first amino group on the reduction of the second nitro group, it is difficult to inhibit eminently the generation of side products and obtain m-phenylenediamine efficiently. Hence it is imperative to establish kinetic network and investigate the intrinsic kinetic parameters of this reaction for further optimization. In this study, a continuous flow system based on micro-packed bed reactor was developed and a kinetic model of the hydrogenation of m-dinitrobenzene was established successfully. The activation energies and pre-exponential factors were acquired using the kinetic network and the kinetic model exhibited reasonable fit for the transformation of each substance. Moreover, the influence of pressure was investigated, and the accuracy of kinetic model was validated by the comparison with the values in literature. This kinetic model enabled the accurate determination of kinetic parameters with Pt/C and Ni/SiO2 catalysts, and provided the rate determining steps and characteristics of different catalysts for the process optimization.

Controllable integration of metal nanoparticles (NPs) and metal–organic frameworks (MOFs) is of significant importance in many applications owing to their unique properties. In situ efficient synthesis of metal NPs with different structures into MOFs is a great challenge. Herein, we report the nanostructures of octahedron and flower Pt–Cu frame@HKUST-1, which is successfully synthesized under a microwave irradiation method in only 30 min. In this study, Pt–Cu alloys, serving as the self-template, are synthesized first, followed by the HKUST-1 shell growing in situ via the consumption of Cu0. As multifunctional catalysts, the core–shell structures exhibit excellent performance for the hydrogenation of 1-hexene. Notably, octahedron Pt–Cu frame@HKUST-1 displays high turnover number (TON) and turnover frequency (TOF) of 1004 and 2008 h–1, respectively. Thanks to the protective effect of HKUST-1, the octahedron Pt–Cu frame@HKUST-1 can be recycled for at least four runs without serious loss of activity and obvi...

This study investigated the feasibility of using calcined layered double hydroxides (CLDHs) to prevent chloride-induced deterioration in reinforced concrete. CLDHs not only adsorbed chloride ions in aqueous solution with a memory effect but also had a much higher binding capacity than the original layered double hydroxides (LDHs) in the cement matrix. We investigated this adsorption in hardened cement paste in batch cultures to determine adsorption isotherms. The measured and theoretical binding capacities (153 mg g

Th is publication was based on work supported by Award No. KUS-C1-018-02, made by King Abdullah University of Science and Technology (KAUST). Experimental details of the synthesis and characterization of the sorbent. Adsorption and desorption of the sorbent.

Monodispersed hollow spherical mesoporous particles with tunable particle size and shell thickness were readily synthesized using latex templates and a silica precursor in a weakly basic ethanol−water mixture.

A novel high efficiency nanocomposite sorbent for CO2 capture has been developed based on oligomeric amine (polyethylenimine, PEI, and tetraethylenepentamine, TEPA) functionalized mesoporous silica capsules. The newly synthesized sorbents exhibit extraordinary capture capacity up to 7.9 mmol g−1 under simulated flue gas conditions (pre-humidified 10% CO2). The CO2 capture kinetics were found to be fast and reached 90% of the total capacities within the first few minutes. The effects of the mesoporous capsule features such as particle size and shell thickness on CO2 capture capacity were investigated. Larger particle size, higher interior void volume and thinner mesoporous shell thickness all improved the CO2 capacity of the sorbents. PEI impregnated sorbents showed good reversibility and stability during cyclic adsorption–regeneration tests (50 cycles).