Effect of Silica Support on Ru-Cu Cluster Morphology As Determined by Catalytic Activity

Article abstract of DOI:10.1021/j100294a040

Several silica supports impregnated with 1percent Ru and a 1:1 atomic ratio of Ru:Cu in the bimetallic catalysts have been characterized by H2 chemisorption, temperature programmed desorption and re-reduction, and several catalytic reactions of varying structure sensitivity.Clusters of Ru-Cu on one of the silicas, Cab-O-Sil HS5, is distinguished by the fact that only on this support is hydrogen chemisorption suppressed by added Cu.It is postulated that the morphology of the Ru-Cu clusters on HS5 involves a Cu-rich mixture of Ru and Cu on a Ru core.Clusters of Ru-Cu on other silicas appear to be more heterogeneous and have an associated pure Cu phase.Hydrogen spillover occurs with the latter morphology and both hydrogen chemisorption and spillover are suppressed by the morphology of clusters on HS5.