Raman spectra and surface-enhanced Raman scattering （SERS） spectra of filter paper and silica gel plate are ob- tained at 785-nm excitation wavelength. The results show that filter paper has thirteen Raman lines in ...Raman spectra and surface-enhanced Raman scattering （SERS） spectra of filter paper and silica gel plate are ob- tained at 785-nm excitation wavelength. The results show that filter paper has thirteen Raman lines in 800 - 1 500 cm 1 and silica gel plate has eight lines in the region of 400 - 1 200 cm-I. The frequencies and Raman active modes are assigned. By comparing their Raman spectra and SERS spectra, we find that the silver colloid could repress the Raman intensities of filter paper and silica gel plate, and reduce their effects on the combination of thin-layer chromatographic （TLC） and SERS. Ac- cording to SERS spectra, the bands at 997 cm 1,1 094 cm I ,1 118 cm-1 ,1 336 cm-1 and 1 378 cm-1 for filter paper and the peak of v l [ SO4] symmetric stretching vibration （--1 017 cm-1 ） for silica gel plate also have high intensities, and those lines should be paid enough attention in TLC-SERS.展开更多
SAPO-34 catalyst with plate-like morphology was designed and synthesized for the first time, by the dry gel conversion method using cheap triethylamine as a structure-directing agent assisted with seed suspension cont...SAPO-34 catalyst with plate-like morphology was designed and synthesized for the first time, by the dry gel conversion method using cheap triethylamine as a structure-directing agent assisted with seed suspension containing nanosheet-like SAPO-34 seed. The latter played an important role in formation of SAPO-34 （CHA-type） with plate-like morphology. In addition, the yield of the product in the synthesis system containing seed suspension reached 97%, 15% higher than that obtained in the corre- sponding synthesis system without the seed suspension. Meanwhile, the plate-like SAPO-34 catalysts synthesized by this method exhibited higher selectivity to light olefins and longer lifetime in methanol-to-olefins （MTO） reaction than the traditional cubic SAPO-34 catalyst. This work provides a new technical route for green and efficient synthesis of SAPO-34 catalysts with improved MTO performance.展开更多
基金Programs for Science and Technology Development of Shandong,China(No.2010GSF10285)
文摘Raman spectra and surface-enhanced Raman scattering （SERS） spectra of filter paper and silica gel plate are ob- tained at 785-nm excitation wavelength. The results show that filter paper has thirteen Raman lines in 800 - 1 500 cm 1 and silica gel plate has eight lines in the region of 400 - 1 200 cm-I. The frequencies and Raman active modes are assigned. By comparing their Raman spectra and SERS spectra, we find that the silver colloid could repress the Raman intensities of filter paper and silica gel plate, and reduce their effects on the combination of thin-layer chromatographic （TLC） and SERS. Ac- cording to SERS spectra, the bands at 997 cm 1,1 094 cm I ,1 118 cm-1 ,1 336 cm-1 and 1 378 cm-1 for filter paper and the peak of v l [ SO4] symmetric stretching vibration （--1 017 cm-1 ） for silica gel plate also have high intensities, and those lines should be paid enough attention in TLC-SERS.
文摘SAPO-34 catalyst with plate-like morphology was designed and synthesized for the first time, by the dry gel conversion method using cheap triethylamine as a structure-directing agent assisted with seed suspension containing nanosheet-like SAPO-34 seed. The latter played an important role in formation of SAPO-34 （CHA-type） with plate-like morphology. In addition, the yield of the product in the synthesis system containing seed suspension reached 97%, 15% higher than that obtained in the corre- sponding synthesis system without the seed suspension. Meanwhile, the plate-like SAPO-34 catalysts synthesized by this method exhibited higher selectivity to light olefins and longer lifetime in methanol-to-olefins （MTO） reaction than the traditional cubic SAPO-34 catalyst. This work provides a new technical route for green and efficient synthesis of SAPO-34 catalysts with improved MTO performance.
