Abstract: The temperature-programmeddesorption(TPD)was used tostudythe adsorptionandthermal decomposition of 2-propanol and trifluoro-2-propanol on clean Ni(100) surface. The products of TPD in both cases were traced for molecular desorption and for the products of dehydration (alkene) and dehydrogenation (ketone) reactions. The results showed that a partial switch from alcohol dehydrogenation to alcohol dehydration was driven by substitution of γ-hydrogen with more electronegative fluorine atoms. The inductive effect exerted by fluorine atoms substituted at the γ position led to a significant inhibition of β-hydride elimination from the alkoxide intermediates, and to the opening of a new γ-hydride elimination channel which eventually ended in alkene formation. While exclusive dehydrogenation to acetone via β-hydride elimination from 2-propoxide surface species was seen with 2-propanol, some dehydration to 3,3,3-trifluoropropene was observed with 1,1,1-trifluoro-2-propanol.

Key words: 2-propanol, Trifluoro-2-propanol, TPD, Ni(100)