Huang Fan, Li Jiang, Wang Lian, Dong Ting, Tu Jing, Torimoto Yoshifumi, Sadakata Masayoshi, Li Quanxin
Department of Chemical Physics, Lab of Biomass Clean Energy, University of Science & Technology of China, Hefei, Anhui, 230026, PR China.
J Phys Chem B. 2005 Jun 23;109(24):12032-7. doi: 10.1021/jp050006g.
The hydrogen anion (H-) and other anionic species (O-, OH-, e-) in the gas phase, emitted from the synthesized crystal surface of 12 CaO x 7 Al2O3-H- (C12A7-H-), have been observed. The emission intensity of all the anionic species strongly depends on the sample surface temperature and the extraction field. H- has the highest emission branch ratio, and the extraction field can reduce its apparent activation energy. H- emission current at a microA/cm2-level has been achieved, which is about 4 orders of magnitude higher than that obtained from the thermal desorption process of CaH2. The observed anions of H- and OH- are attributed to their migration from the C12A7-H- cages onto the surface [i.e., Y-(cages) --> Y-(surface) --> Y-(gas phase) (Y = H, OH)]. The weak O- and electron emission would both arise from the dissociation of O2-: O2-(surface) --> O-(surface) + e-(surface) --> O-(gas phase) + e-(space).
已观察到从12CaO·7Al₂O₃ - H⁻（C12A7 - H⁻）合成晶体表面发射出的气相中的氢阴离子（H⁻）和其他阴离子物种（O⁻、OH⁻、e⁻）。所有阴离子物种的发射强度强烈依赖于样品表面温度和提取场。H⁻具有最高的发射分支比，并且提取场可以降低其表观活化能。已实现了微安/平方厘米级别的H⁻发射电流，这比从CaH₂的热解吸过程中获得的电流高约4个数量级。观察到的H⁻和OH⁻阴离子归因于它们从C12A7 - H⁻笼迁移到表面上[即，Y⁻（笼）→Y⁻（表面）→Y⁻（气相）（Y = H，OH）]。较弱的O⁻和电子发射都将源于O²⁻的解离：O²⁻（表面）→O⁻（表面）+ e⁻（表面）→O⁻（气相）+ e⁻（空间）。
