A new naphthalene derivative, 1-methyl-2,3-methylenedioxy-6-naphthalenecarboxylic acid methyl ester (1), and a new alkaloid, ( ± )-1-phenyl-2-imido-1-propanol (2), together with the four known compounds, ephedrine, pseudoephedrine, N-methylephedrine, and 6-methoxykynurenic acid, have been isolated from the stems of Ephedra sinica, a famous traditional Chinese herbal medicine. The structures of 1 and 2 were determined by spectroscopic methods, including 1D- and 2D-NMR experiments as well as HR-EI-MS analysis.
Developing an efficient catalyst is desirable when for example moving from a noble metal-based catalyst to a transition metal-based one for VOC removal. In this work, the chloropropyl-modified NaY zeolite (NaY-CPT) was first synthesized in an extremely dense system through introducing 3-chloropropyl-trimethoxysilane (CPT) in the aluminosilicate sol. Then the Cu/Y-CPT catalyst was fabricated by impregnating Cu species on the NaY-CPT zeolite and the highly effective Cu/Y based catalyst has been achieved for catalytic toluene oxidation. The structure evolution of CPT modified sol and its effect on texture properties of NaY-CPT and thereby reduction ability of Cu/Y catalyst were systematically investigated by synchrotron radiation small angle X-ray scattering (SR-SAXS), EXAFS and other characterization. The CPT modified sol can promote the formation of more active aluminosilicate species, greatly accelerating crystal growth and improving framework Si/Al ratio of NaY zeolite. Due to the presence of the CPT group, the Cu/Y-CPT catalyst enhanced the interaction between Cu species and the zeolite matrix, resulting in small sized CuO nanoparticles (2.0–4.0 nm) anchoring to NaY-CPT. The Cu/Y-CPT catalyst renders more isolated Cu2+ species and adsorbed oxygen species, which are reactive in the oxidation reaction due to their high reducibility and mobility. Finally, the Cu/Y-CPT catalyst exhibits 90% toluene conversion at 296 °C (T90), lower than the value of 375 °C on the conventional Cu/Y-con catalyst. Meanwhile, the optimal Cu/Y-CPT catalyst also gives higher toluene conversion and stability in moisture conditions.
1 July 2018 in Microporous and Mesoporous Materials
The change in the fractal structure of anthracite mined in Jincheng, China, during high-temperature (1200°C) carbonisation was studied in situ by small-angle X-ray scattering (SAXS) at Beijing Synchrotron Radiation Facility (BSRF). The results show that, during carbonisation, the anthracite structure changes from a pore fractal to a surface fractal and then back to a pore fractal. With increase of temperature, the fractal dimension of the sample presents a trend of rise, decline, rise and decline again, which probably corresponds to the four stages of physical desorption, thermal decomposition, thermal condensation, and residual carbon aging in the process of carbonisation. The pore fractal exists in the initial and final stages, and the surface fractal exists in the middle two stages.