The effects of surface poisoning by HCl on cyclization processes on a Cu3Pt(1 1 1) surface

The effects of surface poisoning on the dehydrocyclization processes for C6 hydrocarbons are analyzed. 6-bromo-1-hexene and 1-hexene reactions on the Cu3Pt(1 1 1) surface leading to benzene formation can be inhibited completely when the alloy surface is predosed with HCl as a chlorinating agent. The Cu:Pt ratio on a surface of the alloy crystal did not change significantly upon addition of HCl within the errors of our measurements. The rates of dehydrocyclization processes were suppressed as a linear function of the HCl dosed. Thermal desorption mass spectrometry and Auger electron spectroscopy were used to characterize the surface processes and obtain experimental information about the mobility of chlorine on the alloy surface and about the potential role of platinum and copper atoms in dehydrocyclization.