研究NO在SrTiO_3表面的吸附特性

Characteristic of Adsorption of NO Gas on the SrTiO_3 Surface

采用TPD实验方法测定了N18O在SrTiO3表面吸附后的脱附谱,揭示了气体脱附量的变化规律.结果表明N18O在SrTiO3表面吸附后脱附出大量的N16O气体,还脱附出少量的N2,N18O和N216O气体.这说明了在吸附和脱附过程中N18O与SrTiO3表面发生氧的同位素交换.N16O的脱附量随N18O气体暴露量增加而增加,但当气体覆盖度超过一定值后,脱附量趋于定值.

The desorption spectrum of N^18O adsorbed on the surface of SrTiO3 powder was determined by Temperature Programmed Desorption （TPD）.The changes of desorption amount were discussed.The results indicate that the mass of N^16O desorption is followed with N^18O of adsorption on SrTiO3.Otherwise a small amount of N2,N^18O and N2^16O also desorbed from the particle surface.N^16O formed due to the exchange of oxygen isotopes and escaped from the surface of SrTiO3 particles during heating the particles pretreated with the absorption of N^18O gas.With increasing the exposure amount of N^18O gas,the desorption amount of N^16O increased and the peak desorption temperature decreased.However,the desorption amount of N^16O tended to become constant when the surface coverage of N^18O gas was higher than a certain value.