Steering and optimizing catalyst selectivity at ¿ simultaneously - adequate catalyst activity is a continuing challenge in chemical technology and of high economic impact. In RB101610 we have shown that the combination IINS, TEM and EDX is uniquely suitable to reveal the influence of lead in reducing the solubility of hydrogen and the relative proportion of alpha- and beta-phase palladium hydride at given hydrogen partial pressure, which is a central feature in improving the selectivity of the Lindlar catalyst in reducing triple bonds to double bonds (e.g.) in the technical synthesis of Vitamin A. In these catalysts the palladium was present as supported aggregates of 10-15 nm size. We would like to complete this investigation by probing hydrogen interactions of isolated primary particles of Pd on carbon black in catalysts used for the hydrogenation of aromatic nitro groups to amines