Probing the Kinetics for Thiol Desulfurization: The Reactions of 2-Methyl-2-propanethiol on Mo(110)

Article abstract of DOI:10.1021/j100190a073

The reactions of 2-methyl-2-propanethiol on Mo(110) were studied using temperature programmed reaction, high resolution electron energy loss, and X-ray photoelectron spectroscopies.The sulfur-hydrogen bonds breaks upon adsorption at 120 K, yielding adsorbed 2-methyl-2-propyl thiolate and hydrogen.Thiolate hydrogenolyis produces isobutane, while cleavage of the C-S and selective C-H bond breaking β to the sulfur yields isobutene.Nonselective decomposition to adsorbed carbon, sulfur and gaseous dihydrogen is a competing channel.At reaction saturation, the selectivity for hydrocarbon formation is 80percent.The specific butane and butene isomers were identified on the basis of the differences in the fragmentation patterns of the various isomers when an electron energy of 27 eV was used in the mass spectrometer.The isomeric selectivity corroborates our general mechanism for thiolate reaction.Isobutane formation preceded ethane formation for a 2-methyl-2-propanethiol/ethanethiol mixture.The kinetics for 2-methyl-2-propyl thiolate desulfurization were found to increase with increasing 2-methyl-2-propyl thiolate coverage.