Quantitative detection of reactive hydrogen on MoS sub 2 /. gamma. -Al sub 2 O sub 3 and on. gamma. -Al sub 2 O sub 3

Hydrogenation of 2-methyl-1,3-butadiene (isoprene) under helium flow in the absence of gaseous hydrogen is used to titrate reactive hydrogen species present in MoS{sub 2} supported on {gamma}-Al{sub 2}O{sub 3} previously submitted to a H{sub 2} treatment at various temperatures T{sub R} MoS{sub 2}/{gamma}-Al{sub 2}O{sub 3} is found to be a hydrogen reservoir and the hydrogen storage depends on the temperature of treatment (T{sub R}) of the solid under H{sub 2}, i.e., on the creation of anionic vacancies on the edges of the supported MoS{sub 2} slabs. A similar results has been obtained on a powdered bulk MoS{sub 2}, which has been investigated by the same dynamic method, but the amount of titrated reactive hydrogen was much lower. Therefore, in the case of MoS{sub 2}/{gamma}-Al{sub 2}O{sub 3}, the role of the support in the reactive hydrogen storage is illustrated and also explained by the creation of anionic vacancies in the oxide phase.