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用程序升温脱附(TPD)和俄歇电子能谱(AES)在80～773K范围内研究了甲硫醉在Ni(100)面上的脱附和分解.结果表明:当甲硫醇暴露度≤3L时(1L=1.33×10~4Pa.S),甲硫醇在表面分解的脱附产物为氢和甲烷;甲硫醇暴露度≤4L时,除有表面反应生成的氢和甲烷脱附外还伴随有甲硫醇的脱附.AES测量表明,由甲硫酸分解产生的硫原子被强吸附在Ni(100)面上,并对Ni(100)面起化学改性的作用.在甲硫醇暴露度为0.5～3L范围内,滞留在表面的强吸附硫量随甲硫醇的暴露度成正比增加.当甲硫醇暴露度等于10L时,强吸附硫量接近饱和值.表面硫的存在对甲硫醇在Ni(100)面上的反应和吸附性能有明显的影响,硫化学改性的主要作用是阻塞了Ni(100)面上的四重穴中心,降低了Ni(100)面对C-H键、C-S键、和S-H键的裂解活性.
The desorption and decomposition of methylthio on Ni (100) surface were studied by temperature programmed desorption (TPD) and Auger electron spectroscopy (AES) in the range of 80 ~ 773 K. The results showed that when methanyl alcohol exposure ≤ 3L (1L = 1.33 × 10 ~ 4Pa.S), the decomposition of methanethiol on the surface of the desorption products of hydrogen and methane; methyl mercaptan exposure ≤ 4L, in addition to the surface reaction of hydrogen and methane desorption Also accompanied by the desorption of methanethiol.AES measurements show that the sulfur atom produced by the decomposition of methane sulfonate is strongly adsorbed on the Ni (100) surface and chemically modifies the Ni (100) In the range of 0.5 ~ 3L, the amount of strongly adsorbed sulfur retained on the surface increased in direct proportion to the exposure of methanethiol, and the amount of strongly adsorbed sulfur approached to saturation when the methanethiol exposure was equal to 10 L. Surface sulfur The main effect of sulfur chemical modification is to obstruct the center of the quadruplet on the Ni (100) surface and reduce the Ni (100) Facing CH, CS, and SH cleavage activity.