Pt‐WOx/C catalysts for α, β‐ unsaturated aldehydes hydrogenation: a NMR study of the effect of the reactant adsorption on activity and selectivity

The selective hydrogenation of α,β-unsaturated aldehydes is an ideal case for studying the structure–activity relationships in heterogeneous catalysis. In particular, cinnamaldehyde can be used as probe molecule for revealing the competition between hydrogenation of C=C and C=O bond. Here, we investigated the effect of the modification of some Pt supported on carbon catalysts by WO x species in cinnamaldehyde hydrogenation as WO x species are reported to increase the adsorption and activation of the C=O group of α, β-unsaturated aldehydes. Classical techniques used for correlating the catalyst activity and the selectivity to the characteristic of the materials (XRD, HAADF-STEM, XEDS mapping and XPS) have been coupled with NMR relaxometry, a ground breaking technique, to disclose how the molecule approaches the catalyst surface. This indeed constitutes a crucial aspect that rule the catalytic activity. Therefore, an innovative, holistic approach have been used to consider the whole catalytic system.