Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (04): 983-989.doi: 10.3866/PKU.WHXB20110410

• PHYSICAL CHEMISTRY OF MATERIALS • Previous Articles     Next Articles

Characterization and Anion Emission Characteristics of the Microporous Crystal Cs-C12A7

NING Shen, SHEN Jing, LI Xing-Long, XU Yong, LI Quan-Xin   

  1. Laboratory of Biomass Clean Energy, Department of Chemical Physics, University of Science & Technology of China, Hefei 230026, P. R. China
  • Received:2010-11-26 Revised:2011-01-17 Published:2011-03-29
  • Contact: LI Quan-Xin E-mail:liqx@ustc.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (50772107), National Key Basic Research Program of China (973) (2007CB210206) and National High-Tech Research and Development Program of China (863) (2009AA05Z435).

Abstract:

Cesium-12CaO·7Al2O3 (Cs-C12A7) was fabricated by adding CsI to the C12A7 surface using incipient wetness impregnation. The X-ray diffraction (XRD) structure determined for the Cs-C12A7 material is the same as that of the 12CaO·7Al2O3 (C12A7) crystal, which belongs to the I43d] space group. The concentrations of O- and O2- in Cs-C12A7 were about (1.3±0.3)×1020 cm-3 and (1.2±0.2)×1020 cm-3, respectively, according to a simulation of the measured electron paramagnetic resonance (EPR) spectrum. This is similar to the data obtained for fresh C12A7 ([O-]=(1.4±0.3)×1020 cm-3 and [O2-]=(1.4±0.3)×1020 cm-3). The CsI particles from the C12A7 surface were observed using field emission scanning electron microscope (FESEM) and conventional transmission electron microscopy (TEM). The emission features of Cs-C12A7, including the emission distribution, field effect and apparent activation energy were investigated in detail and compared with those of C12A7. The advanced emission behavior was attributed to a reduction in the apparent activation energy.

Key words: Atomic oxygen anion, Cs-C12A7, Emission characteristics, Storage characteristics, Apparent activation energy

MSC2000: 

  • O647