Adsorption and reaction of cyclohexene and 1-hexene on nascent gold surface formed by friction

Adsorption and reaction of cyclohexene, 1-hexene and benzene on nascent gold surface formed by friction were investigated using an adsorption test apparatus in high vacuum at room temperature. Chemisorption of cyclohexene, 1-hexene and benzene was observed during the sliding processes by a quadrupole mass spectrometer. It is found that nascent gold surface has catalytic activity for hydrogenation of cyclohexene and 1-hexene, and for dehydrogenation of the olefins and benzene. The adsorbed cyclohexene and 1-hexene molecules were hydrogenated on the surface to form cyclohexane and hexane, respectively. As dehydrogenation products, hydrogen from all the sample gases, and benzene from cyclohexene desorbed. Adsorption rate of the olefins was higher than that of benzene, and hydrogenation activity of 1-hexene is higher than that of cyclohexene. However, on nascent Pd–Ag alloy surface, the desorption of hydrogenation products was not detected, although adsorption of the sample gases and desorption of the dehydrogenation products were also observed.