A Fast XPS Study of Propene Decomposition over Clean and Sulphated Pt{111}
A Fast XPS Study of Propene Decomposition over Clean and Sulphated Pt{111}
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清洁和硫酸化 Pt 上丙烯分解的快速 XPS 研究{111}
DOI：
10.1023/a:1014921021037
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发表时间：
2002
影响因子：
2.8
通讯作者：
Sivano Lizzit
中科院分区：
文献类型：
--
作者：
A. Lee;K. Wilson;A. Goldoni;R. Larciprete;Sivano Lizzit
丙烯在清洁的和硫酸盐预覆盖的Pt{111}上的热分解已经被Fast XPS跟踪。在90 K时，丙烯在清洁表面上的饱和覆盖率为0.21 mL.丙烯在200 K以下是稳定的，高于200 K时，分子脱附和脱氢导致在300 K时形成稳定的次丙炔中间吸附层。丙炔在400 K以上分解，最终在800 K以上形成石墨碳。预吸附的表面硫酸盐促进与热不稳定的烷基-硫酸盐复合物的分解相关的室温丙烯燃烧。丙炔也在干净的Pt{111}上形成，但反应性较低，其在450 K以上的分解引发与残留表面氧的部分氧化以释放气相CO。
The thermal decomposition of propene over clean and sulphate precovered Pt{111} has been followed by Fast XPS. The saturation propene coverage over the clean surface is 0.21 mL at 90 K. Propene is stable up to 200 K, above which molecular desorption and dehydrogenation result in the formation of a stable propylidyne intermediate adlayer at 300 K. Propylidyne decomposes above 400 K eventually forming graphitic carbon above 800 K. Preadsorbed surface sulphate promotes room temperature propene combustion associated with the decomposition of a thermally unstable alkyl--sulphate complex. Propylidyne also forms as on clean Pt{111}, but is less reactive, its decomposition above 450 K triggering partial oxidation with residual surface oxygen to liberate gas phase CO.