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The degradation of tetracycline over Fe 3 O 4 catalyst was studied by using a coupled ultrasound/heterogeneous Fenton process. The effects of some key reaction parameters, the evolution of toxicity, and the reaction mechanism were investigated. Experimental results showed that the stability of catalyst was significantly improved when ultrasound was employed. Under optimal conditions, 93.6% of tetracycline was removed after 60 min of treatment. The removal efficiency of the total organic carbon (TOC) at 60 min was 31.8%. The surface hydroxyl radicals were identified as the major reactive species during the oxidation process. Toxicity tests with Daphnia magna indicated that the toxicity of the solution increased during the first 60 min and then decreased as the oxidation proceeded. [ABSTRACT FROM AUTHOR]

Highlights: [•] The DEC synthesis from CO2, EO and ethanol was attempted for the first time. [•] KI/EtONa as binary catalyst system exhibited higher catalytic performance. [•] This strategy can be successively expanded to terminal epoxides. [•] This method exhibited promising applications on an industrial scale. [ABSTRACT FROM AUTHOR]

Abstract: Lanthanum oxide catalyst prepared by precipitation method and calcined at 600°C exhibited better catalytic activity in the catalytic synthesis of glycerol carbonate from glycerol and urea with TOF up to 1506mmol/g·h. It was proposed that the lanthanum oxide catalyst with more strong basic sites (Td >400°C) exhibited higher catalytic activity. Accordingly, the catalyst containing appropriate amount of La2O2CO3 phase exhibited higher catalytic activity. Moreover, the recycling experiments demonstrated that the catalytic activity can be essentially preserved during the recycling tests investigated. [Copyright &y& Elsevier]

• CeO 2 H, which is prepared using hydrogen peroxide assisted precipitation, is abundant in both acid and base double sites. • CeO 2 H acid-base dual functionality is beneficial for efficient synthesis of HDC, with a yield of up to 96% and a TOF value of 6.66 g HDC g CeO2 H −1 h−1. • The activity of the CeO 2 H catalyst could be retained within five cycles. • CeO 2 H has good catalytic effect on the carbonylation of aliphatic and alicyclic substrates. The carbonylation of 1,6-hexanediamine (HDA) is an important method for the production of dimethyl hexane-1,6-dicarbamate (HDC), which is of great significance for the non-phosgene synthesis of hexamethylene-diisocyanate. This research focuses on the synthesis of HDC through the methoxycarbonylation of HDA using methyl carbamate as a carbonyl source. The study investigates the utilization of CeO 2 catalyst prepared via H 2 O 2 assisted precipitation. Various characterization techniques, including N 2 physical adsorption and desorption, SEM, TEM, XRD, NH 3 TPD, CO 2 TPD, and XPS are employed to analyze the texture and structure of CeO 2 catalysts prepared through different methods. In situ FTIR experiments are conducted to monitor the potential process of the carbonylation reaction. The results of the in situ FTIR spectroscopy clearly indicate the formation of polyurea as an intermediate compound, which subsequently converts into HDC. The findings demonstrate that CeO 2 prepared using the hydrogen peroxide precipitation method exhibits a larger specific surface area, stronger acid-base properties, and a higher content of surface-adsorbed oxygen. These characteristics are favorable for the carbonylation reaction. Under optimized conditions, the HDC yield reaches 96.0% with complete conversion of HDA. The catalyst's activity essentially maintained throughout ten cycles. Additionally, a substrate versatility study reveals that CeO 2 exhibits excellent catalytic properties for synthesizing a range of aliphatic and alicyclic dicarbamates. [Display omitted] [ABSTRACT FROM AUTHOR]

Highlights: [•] Ozone was activated by magnetite and ultrasound for the degradation of sulfamethoxazole. [•] The sulfamethoxazole removal rate followed the pseudo-first-order kinetics. [•] The presence of different types of radical scavengers would inhibit the degradation rate. [•] The acute toxicity was greatly decreased after treatment. [ABSTRACT FROM AUTHOR]

Abstract: A series of CuMgAl hydrotalcites derived oxides were prepared by co-precipitation and calcination methods and tested for the simultaneous catalytic removal of NOx and soot. The obtained samples were characterized by XRD, N2 adsorption-desorption, H2-TPR and ICP-AES techniques. The crystal phases, porous structures and redox properties of the catalysts were strongly influenced by Cu substitution contents and calcination temperatures. The CuMgAl mixed oxides with mesoporous properties exhibit high activity for the simultaneous NOx-soot removal. Among the tested catalysts, 3.0Cu-800 sample shows the best performance with the ignition temperature of soot=260°C and the total amounts of N2 =6.0×10−5 mol. Based on the experimental work, a primitive kinetics analysis was carried out from the non-steady (dynamic) TPR measurements. Linear Arrhenius plots of rates of CO2, N2 and N2O formation were observed around the onset of formation curves where the substantial amount of the soot still remains in the soot/catalyst mixture and the effective area of the soot/catalyst contact can be regarded as constant. Finally, a compensation effect was found for the formation of CO2, N2 and N2O over CuMgAl mixed oxides with CuO as the predominant phase. [Copyright &y& Elsevier]

Abstract: The non-phosgene carbonylation of 1,6-hexamethylenediamine (HDA) with alkyl carbamates using Y(NO3)3·6H2O as a catalyst and the influence of reaction variables on the yields of dialkyl hexamethylenedicarbamate (HDC) were studied. At 453K and in the presence of 5wt.% Y(NO3)3·6H2O, nearly 100% HDA conversion and 85% dibutyl hexamethylenedicarbamate (BHDC) isolated yield could be achieved when butyl carbamate (BC) was employed as a carbonyl source. During reaction, an induction period was observed, but it almost disappeared by pretreating the catalyst with n-butanol. The FT-IR, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) characterizations of the catalyst showed that some transformation occurred when the catalyst was pretreated with n-butanol or employed during reaction, i.e., part decomposition of Y(NO3)3 to Y2O3, conversion from crystal to amorphous state, changes occurring in chemical state of the active species, as well as some subtle interactions between the catalyst and n-butanol. All these observed changes might be the reason resulting in activation of the catalyst. [Copyright &y& Elsevier]