Dehydrogenation of 1:1 mixture of cyclohexane-[14C] plus cyclohexene was studied over six carrier-free VIIIB metals as catalysts with formation of cyclohexene intermediate being evaluated by comparing specific radioactivities of cyclohexene and benzene. Close values were found for cobalt and nickel, whereas the specific radioactivity of benzene was higher for iridium, rhodium, palladium and platinum. Results were interpreted in terms of the existence of two different pathways of cyclohexane dehydrogenation involving 1,2- and 1,3-diadsorbed surface species, respectively; with only the former being able to produce cyclohexene. The ratio of the two mechanisms can be correlated with the atomic diameter of the metal, smaller atoms favouring 1,2-adsorption.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry