Hydrogenation of 1,3-butadiene and 2-methyl-1,3-butadiene and equilibration reaction of H2D2 were carried out over ZrO2 using H2 and Cyclohexadiene as hydrogen sources. Reaction rates were measured by changing the activation temperature of the catalyst. While the hydrogenation with H2 and H2D2 equilibration reaction gave an optimum activity at 600 °C, another optimum was obtained for transfer hydrogenation at 800 °C. Hence it is concluded that the sites responsible for the transfer hydrogenation are not the same as those which catalyze hydrogenation with H2 and H2D2 equilibration. Product distributions in n-butenes and methylated butenes were compared on ZrO2, ThO2, La2O3, and MgO and were also compared in direct hydrogenation with H2 and transfer hydrogenation with Cyclohexadiene. Assuming an ionic intermediate, selectivity changes in the monoolefins produced over different catalysts and by different hydrogen sources were interpreted in terms of the variation of the anionic character of the intermediate and the shift of anionic to neutral or cationic intermediate, respectively.