Hydrogenation of Phenylacetylene to Styrene on Pre-CxHy- and C-Covered Cu(111) Single Crystal Catalysts

Bulletin of the Korean chemical society

b¹  John M. White¹  Wei Wei¹  Youngku Sohn¹ 

关键词: Hydrogenation;    Temperature-programmed desorption;    Phenylacetylene;    Styrene;   

DOI  :  

学科分类：化学（综合）

来源: Korean Chemical Society

【 摘 要 】

Thermal hydrogenation of phenylacetylene (PA, C8H6) to styrene (C8H8) on pre-CxHy- and C-covered Cu(111) single crystal substrates has been studied using temperature-programmed desorption (TPD) mass spectrometry. Chemisorbed PA with an acetylene group has been proved to be associated with hydrogen of pre-adsorbed CxHy to form styrene (104 amu) on Cu surface. For the parent (PA) mass (102 amu) TPD profile, the TPD peaks at 360 K and 410 K are assigned to chemisorbed vertically aligned PA and flat-lying cross-bridged PA, respectively (J. Phys. Chem. C 2007, 111, 5101). The relative I360K/I410K TPD ratio dramatically increases with increasing pre-adsorbed CxHy before dosing PA, while the ratio does not increase for pre-C-covered surface. For PA on pre-CxHy-covered Cu(111) surface, styrene desorption is enhanced relative to the parent PA desorption, while styrene formation is dramatically quenched on pre-C-covered (lack of adsorbed hydrogen nearby) surface. It appears that only cross-bridged PA associates with adsorbed hydrogen to form styrene that promptly desorbs at 410 K, while vertically aligned PA is less likely to participate in forming styrene.

【 授权许可】

Unknown