Mechanism of deuterium addition and exchange with propene over Ni/SiO2 and Pt/SiO2 catalysts at low temperatures

Abstract

The mechanism of the deuterium addition and exchange reaction of propene over Ni/SiO₂ and Pt/SiO₂ has been studied by applying microwave spectroscopy as well as kinetic measurements. The associative mechanism prevails in the presence of gaseous deuterium, while the dissociative mechanism operates in its absence. Over the Ni catalyst, the central carbon C₂ of propene is most active for exchange and n-propyl (associative) and isopropenyl (dissociative) species are the predominant intermediates. Over the Pt catalyst, the terminal methylene carbon C₁ is most active and isopropyl and n-propenyl species are the predominant intermediates.