Abstract 1-Phosphanorbornadiene derivatives were grafted onto various periodically organized mesoporous powders, including a new zirconia/silica mixed oxide synthesized by aerosol techniques. After complexation with the [Rh (CO) 2]+ fragment, these materials were revealed to be more active in olefin hydrogenation than their homogeneous counterparts. The reasons for this higher activity are discussed in the light of theoretical modeling. ...