Reaction mechanism of unsaturated hydrocarbons with deuterium over zinc oxide

Abstract

The mechanism of deuterium addition to propylene, butene and 1,3-butadiene was studied over ZnO at room temperature. Adsorption during the reaction was measured. The mass- and the microwave spectrometric techniques were used to determine the deuterium content and its distribution in the reactants and the products. In the deuteration of propylene, butene and butadiene, the main products were propane-d₂, butane-d₂, and butene-d₂ respectively. Deuterium participates in the addition process in a “molecular form”. The rate of deuteration was determined by the partial pressure of deuterium rather than the amount of chemisorbed deuterium during the reaction. To explain the experimental results, it was proposed that deuteration proceeds probably by interaction between chemisorbed hydrocarbons and deuterium molecules in the gas-phase.