Sustainable preparation of 2-acylbenzothiazoles under the cooperation of ionic liquids and microwave irradiation.

Microwave irradiation (MW) and ionic liquids (ILs) are two of the most promising relatively greener synthetic approaches to preparing value-added chemicals. Herein, a series of 2-acylbenzothiazole derivatives were synthesized for the first time from commercially available α-bromoacetophenones and disulfane-diyl-dianilines through the cooperation of ionic liquids and microwave irradiation under metal- and extra-additives-free conditions. A plausible mechanism involving the successive IL-induced enolation has been proposed.

Exploration of the reaction mechanism of the LaFeO3 oxygen carrier for chemical-looping steam methane reforming: a DFT study.

The CO conversion is expected to be controllable for chemical-looping steam methane reforming. Herein, density functional theory (DFT) calculations were employed to systematically explore the detailed reaction mechanism of CO conversion over the LaFeO3 oxygen carrier. It is found that the FeO2-terminated surface could exhibit better activity for CO adsorption than the LaO-terminated surface. In addition, the FeO2-terminated surface is much more favorable for CO oxidation than the LaO-terminated surface and the Fe-O site is the main active site. The oxygen diffusion process is easier to proceed on the LaO-terminated surface compared with the FeO2-terminated surface. Four pathways for the reaction process between the FeO2-terminated surface and CO were proposed and oxygen diffusion was determined as the rate-limiting step. For the reaction of CO with the LaO-terminated surface, one pathway was considered and CO2 desorption is the rate-limiting step. Comprehensively, the reactivity of CO conversion over the FeO2-terminated surface is superior to that over the LaO-terminated surface. We could control the CO conversion by regulating the oxygen activity of LaFeO3. This work provides guidance for the rational design of LaFeO3 oxygen carriers in the CL-SRM process.

Treatment of phenolic wastewater by anaerobic fluidized bed microbial fuel cell using carbon brush as anode: microbial community analysis and m-cresol degradation mechanism.

Anaerobic fluidized bed microbial fuel cell (AFB-MFC) is a technology that combines fluidized bed reactor and microbial fuel cell to treat organic wastewater and generate electricity. The performance and the mechanism of treating m-cresol wastewater in AFB-MFC using carbon brush as biofilm anode were studied. After 48 h of operation, the m-cresol removal efficiency of AFB-MFC, MAR-AFB (fluidized bed bioreactor with acclimated anaerobic sludge), MAR-FB (ordinary fluidized bed reactor with only macroporous adsorptive resin) and AST (traditional anaerobic sludge treatment) were 95.29 ± 0.67%, 85.78 ± 1.81%, 71.24 ± 1.86% and 70.41 ± 0.32% respectively. The maximum output voltage and the maximum power density of AFB-MFC using carbon brush as biofilm anode were 679.7 mV and 166.6 mW/m2 respectively. The results of high-throughput sequencing analysis indicated the relative abundance of dominant electroactive bacteria, such as Trichococcus, Geobacter, and Pseudomonas, on the anode carbon brushes was higher than that of AST, and also identified such superior m-cresol-degrading bacteria as Bdellovibrio, Thermomonas, Hydrogenophaga, etc. Based on the determination of m-cresol metabolites detected by Gas Chromatography-Mass Spectrometry (GC-MS), the possible biodegradation pathway of m-cresol under anaerobic and aerobic conditions in AFB-MFC was speculated. The results showed that m-cresol was decomposed into formic acid-acetic anhydride and 3-methylpropionic acid under the action of electrochemistry, which is a simple degradation pathway without peripheral metabolism in AFB-MFC.

Comparative Study of the Supercapacitive Performance of Three Ferrocene-Based Structures: Targeted Design of a Conductive Ferrocene-Functionalized Coordination Polymer as a Supercapacitor Electrode.

As redox-active based supercapacitors are known as highly desirable next-generation supercapacitor electrodes, the targeted design of two ferrocene-functionalized (Fc(COOH)2 ) clusters based on coinage metals, [(PPh3 )2 AgO2 CFcCO2 Ag(PPh3 )2 ]2 ⋅7 CH3 OH (SC1 : super capacitor) and [(PPh3 )3 CuO2 CFcCO2 Cu(PPh3 )3 ]⋅3 CH3 OH (SC2 ), is reported. Both structures are fully characterized by various techniques. The structures are utilized as energy storage electrode materials, giving 130 F g-1 and 210 F g-1 specific capacitance at 1.5 A g-1 in Na2 SO4 electrolyte, respectively. The obtained results show that the presence of CuI instead of AgI improves the supercapacitive performance of the cluster. Further, to improve the conductivity, the PSC2 ([(PPh3 )2 CuO2 CFcCO2 ]∞ ), a polymeric structure of SC2 , was synthesized and used as an energy storage electrode. PSC2 displays high conductivity and gives 455 F g-1 capacitance at 3 A g-1 . The PSC2 as a supercapacitor electrode presents a high power density (2416 W kg-1 ), high energy density (161 Wh kg-1 ), and long cycle life over 4000 cycles (93 %). These results could lead to the amplification of high-performance supercapacitors in new areas to develop real applications and stimulate the use of the targeted design of coordination polymers without hybridization or compositions with additive materials.

Co-P bond effect on an MOF-derived Co9S8 hollow polyhedron supported Ni2P co-catalyst for efficient photocatalytic hydrogen evolution.

The development of new, efficient noble-metal-free photocatalysts is of great significance for the photocatalytic hydrogen evolution reaction. Herein, Co9S8 with a hollow polyhedral structure was synthesized by in situ sulfurization of ZIF-67, and subsequently, Co9S8@Ni2P composite photocatalytic materials were prepared by loading Ni2P on the surface of Co9S8 through a solvothermal method based on a morphology regulation strategy. The design of the 3D@0D spatial structure of Co9S8@Ni2P is favorable for the formation of photocatalytic hydrogen evolution active sites. Due to the excellent metal conductivity of Ni2P, Ni2P as a cocatalyst can accelerate the separation of photogenerated electrons from holes in Co9S8, thus providing a large number of available photogenerated electrons for photocatalytic reactions. It is worth mentioning that a Co-P chemical bond is formed between Co9S8 and Ni2P, which plays an active role in the transport of photogenerated electrons. The densities of states of Co9S8 and Ni2P were determined by density functional theory (DFT) calculations. The reduction of the hydrogen evolution overpotential and the formation of efficient charge-carrier transport channels on Co9S8@Ni2P were confirmed by a series of electrochemical and fluorescence tests. This study provides a new idea for the design of highly active noble-metal-free materials for the photocatalytic hydrogen evolution reaction.

Analysis and discussion on formation and control of dioxins generated from municipal solid waste incineration process.

Dioxins are a kind of persistent organic pollutants (POPs) with extremely toxic. Municipal solid waste incineration (MSWI) process has become one of the most dominant discharge sources of dioxins. A comprehensive discussion about dioxin formation mechanisms was reviewed in this paper, and the mechanisms of high-temperature gas-phase reaction and "de novo" synthesis were systematically illustrated in the form of diagrams. What's more, the effects of various influencing factors on the formation of PCDD/Fs were briefly analyzed in the form of a table. We believed that temperature, catalyst, chlorine source, carbon source, oxygen concentration and moisture were necessary factors for PCDD/Fs formation. Control technologies of dioxins in MSWI process were summarized subsequently from three stages: pre-combustion, in-combustion and post-combustion, and a device for synergistic removal of dioxins based on multi-field force coupling and technical routes for controlling dioxin emissions were proposed, so as to provide mechanisms and methods for effectively reducing the emission concentration of dioxins. An introduction was also conducted of dioxin control technologies in municipal solid waste incineration fly ash (MSWI-FA) in this paper, and their mechanisms, advantages, disadvantages and technical maturity were illustrated in the form of diagrams, which can provide theory and reference for in-depth research of follow-up scholars and industrial application of dioxin control technologies. Finally, current research hotspots, challenges and future research directions were proposed.Implications: In this paper, the main research contents and achievements are as follows: With the emphasis placed on the formation mechanism of dioxins and effects of various influencing factors on the formation of PCDD/Fs. The control technology of dioxins in MSWI process is summarized subsequently from three stages: pre-combustion, in-combustion and post-combustion.A device for synergistic removal of dioxins based on multi-field force coupling and technical routes for controlling dioxin emissions are proposed.A systematic review is conducted of the research progress on control technologies of dioxins in MSWI fly ash in the most recent years.The mechanisms, advantages, disadvantages and technical maturity of PCDD/Fs degradation technologies in MSWI fly ash are illustrated in the form of diagrams.Current research hotspots, challenges and future research directions are proposed.

The development of activated carbon from corncob for CO2 capture.

The accumulation and incineration of crop waste pollutes the environment and releases a large amount of CO2. In this study, corncob crop waste was directly activated using solid KOH in an inert atmosphere to prepare porous activated carbon (AC) to capture CO2, and to introduce N-containing functional groups that favour CO2 adsorption, urea was mixed with corncob and KOH to prepare N-doped AC. The physical and chemical properties of the AC were characterized, and the effects of the mass ratio of KOH and urea to corncob, the activation temperature and time as well as regeneration were investigated to explore the optimal preparation process. The pores in the AC are mainly micropores, with the specific surface area and pore volume reaching 926.07 m2 g-1 and 0.40 cm3 g-1 for KOH-activated corncob and 1096.70 m2 g-1 and 0.48 cm3 g-1 after N-doping; the C-O plus O-H ratio and the -NH- ratio, which favour CO2 adsorption in N-doped AC were 6.04 and 1.92%, respectively. The maximum adsorption capacities for KOH-activated corncob before and after N-doping were 3.49 and 4.58 mmol g-1, respectively, at 20 °C and remained at 3.44 and 4.52 mmol g-1 after ten regenerations. The prepared corncob-based AC showed good application prospects for CO2 capture.

Development of Low-Cost Porous Carbons through Alkali Activation of Crop Waste for CO2 Capture.

To achieve the "double carbon" (carbon peak and carbon neutrality) target, low-cost CO2 capture at large CO2 emission points is of great importance, during which the development of low-cost CO2 sorbents will play a key role. Here, we chose peanut shells (P) from crop waste as the raw material and KOH and K2CO3 as activators to prepare porous carbons by a simple one-step activation method. Interestingly, the porous carbon showed a good adsorption capacity of 2.41 mmol/g for 15% CO2 when the mass ratio of K2CO3 to P and the activation time were only 0.5 and 0.5 h, respectively, and the adsorption capacity remained at 98.76% after 10 adsorption-desorption cycle regenerations. The characterization results suggested that the activated peanut shell-based porous carbons were mainly microporous and partly mesoporous, and hydroxyl (O-H), ether (C-O), and pyrrolic nitrogen (N-5) functional groups that promoted CO2 adsorption were formed during activation. In conclusion, KOH- and K2CO3-activated P, especially K2CO3-activated P, showed good CO2 adsorption and regeneration performance. In addition, not only the use of a small amount of the activator but also the raw material of crop waste reduces the sorbent preparation costs and CO2 capture costs.

Polypropylene Composites Reinforced by Nonmetallic from Waste Printed Circuit Boards Using Spout-Fluid Bed Coating with PP Particles Enhance Fluidization.

Nonmetallic materials recycled from waste printed circuit boards (N-WPCBs) were modified by coating KH-550 in a spout-fluid bed. To improve the effect of the modification, PP particles were used to enhance the fluidization quality of the N-WPCB particles in the coating modification. Then, the modified N-WPCBs were used as fillers to fabricate PP/N-WPCB composites. The method of coating in a spout-fluid bed with PP particles enhanced fluidization and showed the best modification effect compared to other coating methods. The FT-IR and SEM results demonstrated that interfacial bonding between N-WPCBs and PP could be enhanced by modified N-WPCBs, which improved the mechanical properties of the composites. When the mass ratio of PP to N-WPCBs is 100:75 and the dose of KH-550 is 4 phr, the flexural strength, tensile strength, and impact strength of the composites increase by 16.60%, 23.22%, and 23.64%, respectively. This would realize the high-value utilization of N-WPCBs with coating modification in the spout-fluid bed.

Tailoring the CO2-selectivity of interfacial polymerized thin film nanocomposite membrane via the barrier effect of functionalized boron nitride.

Membrane-based separation is an appealing solution to mitigate CO2 emission sustainably due to its energy efficiency and environmental friendliness. Attributed to its excellent separation endowed by nanomaterial incorporation, nanocomposite membrane is rigorously developed. This study explored the feasibility of boron nitride (BN) embedment and changes to formation mechanism of ultrathin selective layer of thin film nanocomposite (TFN) are investigated. The effects of amine-functionalization on nanosheet-polymer interaction and CO2 separation performance are also identified. Participation of nanosheets during interfacial polymerization reduced the crosslinking of selective layer, hence, improved TFN permeance while the formation of contorted diffusion paths by the nanosheets favors transport of small gases. Amine-functionalization enhanced the nanosheet-polymer interaction and elevated the membrane affinity towards CO2 which led to enhanced CO2 selectivity. The best TFN prepared in this study exhibited 37% and 20% increment in permeability and selectivity, respectively with respect to neat thin film composite (TFC). It is found that the CO2 separation performance of BN incorporated TFN is on par with many non-porous nanosheet-incorporated TFNs reported in literatures. The transport and barrier effects of BN and functionalized BN are discussed in detail to provide further insights into the development of commercially attractive CO2 selective TFN membranes.

Metal- and oxidant-free electrochemically promoted oxidative coupling of amines.

The selective oxidation of amines into imines is a priority research topic in organic synthesis and has attracted much attention over the past few decades. However, the oxidation of amines generally suffers from the drawback of transition-metal, even noble-metal catalysts. Thus, the strategy of metal- and oxidant-free selective synthesis of imines is highly desirable yet largely unmet. This paper unravels a metal-free and external oxidant-free electrochemical strategy for the oxidative coupling methodology of amines. This general transformation is compatible with various functional amines and led to functionalized imines in moderate to satisfactory yields.

Investigation on the Chemical-Looping Reaction Characteristics of Ningdong Coal with Manganese Ore.

In order to explore an efficient and clean conversion way of Ningdong coal, the chemical-looping reaction of Ningdong coal was conducted in a laboratory-scale fluidized-bed reactor using manganese ore as the oxygen carrier (OC), and the reaction characteristics were investigated in combination by thermogravimetric analysis. Experiments included the investigation of the reaction of the manganese ore with 5 vol % H2 and with coal powder at 900 °C, the catalytic and OC effect of manganese ore on coal gasification, the reaction efficiency and reaction products under different mass ratios of OC to coal (O/C), and the effect of multiple cycles on the reaction performance of the manganese ore. At 900 °C, the OC exhibited higher reactivity with coal syngas, significantly reducing the time of coal gasification (∼48% reduction). The manganese ore itself contained alkali metals, exhibiting a certain capacity for sulfur fixation, but the sulfur fixation was gradually weakened during multicycle experiments. The manganese ore did not exhibit any inhibition effect on NO x emission. From the wear rate of the manganese ore during fluidized reaction, its service life could be deduced to be about 150 h. Hence, it is necessary to improve the strength of the manganese ore OC.

Adsorption of Tetracycline by Shrimp Shell Waste from Aqueous Solutions: Adsorption Isotherm, Kinetics Modeling, and Mechanism.

The highly efficient removal of tetracycline (TC) from an aqueous solution was accomplished by using the raw shrimp shell waste (SSW) as an environmentally friendly adsorbent. The SSW without any treatment removed TC more efficiently than the SSW after being treated with HCl and NaOH solutions. The SSW was characterized using nitrogen adsorption-desorption isotherms, scanning electron microscopy alongside energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, a thermogravimetric-derivative thermogravimetry analyzer, and a ζ-potential analyzer. The maximum adsorption capacity of 400 mg/L SSW was 229.98 mg/g for 36 h at 55 °C. Both the Langmuir isotherm model and the pseudo-second-order kinetic model well described the experimental data. According to the values of the Gibbs free energy and enthalpy changes, the TC adsorption by SSW proved to be spontaneous and endothermic. The TC adsorption process was controlled by intraparticle diffusion and liquid film diffusion.

The dynamic CO2 adsorption of polyethylene polyamine-loaded MCM-41 before and after methoxypolyethylene glycol codispersion.

To reduce the cost of CO2 capture, polyethylene polyamine (PEPA), with a high amino density and relatively low price, was loaded into MCM-41 to prepare solid sorbents for CO2 capture from flue gases. In addition, methoxypolyethylene glycol (MPEG) was codispersed and coimpregnated with PEPA to prepare composite sorbents. The pore structures, surface functional groups, adsorption and regeneration properties for the sorbents were measured and characterized. When CO2 concentration is 15%, for 30, 40 and 50 wt% PEPA-loaded MCM-41, the equilibrium adsorption capacities were respectively determined to be 1.15, 1.47 and 1.66 mmol g-1 at 60 °C; for 30 wt% PEPA and 20 wt% MPEG, 40 wt% PEPA and 10 wt% MPEG, and 50 wt% PEPA and 5 wt% MPEG codispersed MCM-41, the equilibrium adsorption capacities were respectively determined to be 1.97, 2.22 and 2.25 mmol g-1 at 60 °C; the breakthrough and equilibrium adsorption capacities for 50 wt% PEPA and 5 wt% MPEG codispersed MCM-41 respectively reached 2.01 and 2.39 mmol g-1 at 50 °C, all values showed a significant increase compared to PEPA-modified MCM-41. After 10 regenerations, the equilibrium adsorption capacity for codispersed MCM-41 was reduced by 5.0%, with the regeneration performance being better than that of PEPA-loaded MCM-41, which was reduced by 7.8%. The CO2-TPD results indicated that the mutual interactions between PEPA and MPEG might change basic sites in MCM-41, thereby facilitating active site exposure and CO2 adsorption.

Characteristics of a CaSO4 composite oxygen carrier supported with an active material for in situ gasification chemical looping combustion of coal.

CaSO4 is considered to be a potential oxygen carrier for chemical-looping combustion (CLC) due to its cheapness and high oxygen transport capacity. To improve the physicochemical stability of the CaSO4 oxygen carrier, CaSO4 composite oxygen carriers supported with clay, cement, and ash separately were prepared. It was found that the attrition resistance of the CaSO4 oxygen carrier composed of clay and cement improved due to the bond action of clay and cement. The reactivity of the composite oxygen carrier with coal was investigated in a thermogravimetric analyser (TGA) and fluidised bed. Sulphurous gas products were analysed by mass spectrometry (TG-MS) and gas chromatography (GC). Based on the catalysis of the active components in clay, cement and ash, the reaction rate of CaSO4 with coal was improved by the active materials. However, the side reaction generating the sulphurous gas was severe in both the reduction and oxidation stages, especially when using steam as the gasifying agent. To enhance the regeneration, the CaSO4/clay composite oxygen carrier was upgraded by adding CaO. It was demonstrated that SO2 release can be restrained in both the reduction and oxidation stages when the mass ratio of CaO to the CaSO4/clay composite oxygen carrier was higher than 1. At this point, the corresponding oxygen transport capacity was about 14.1 wt%.

The further activation and functionalization of semicoke for CO2 capture from flue gases.

To systematically study CO2 adsorption performance, semicoke from the low-rank lignite was further activated and functionalized for CO2 capture from flue gases. The effect of the activation conditions, such as the activation temperature, activation time and HCl washing, and the tetraethylenepentamine (TEPA)-functionalization on CO2 adsorption were investigated; the pore structure and surface morphology of the semicoke under different activation conditions were characterized. Both the surface structure and adsorption performance of the activated semicoke could be improved under appropriate activation and acid-treatment conditions. The optimal breakthrough and equilibrium adsorption capacity for the TEPA-functionalized HCl-washed activated semicoke were separately 2.68 and 3.70 mmol g-1 at 60 °C for the simulated flue gas of 15 vol% CO2 and 85 vol% N2. After ten adsorption-desorption cycles, the equilibrium adsorption capacity was still 3.43 mmol g-1, and the semicoke-based sorbent showed good regenerability.