Observation of Parahydrogen‐Induced Polarization in Heterogeneous Hydrogenation on Supported Metal Catalysts

Contrary to popular opinion, two H atoms from the same H2 molecule can end up in the same product molecule and retain their spin correlation during heterogeneous hydrogenation on supported metal catalysts and thus produce parahydrogen-induced nuclear spin polarization in the reaction products (see picture). For 0.6-nm Pt clusters on alumina, the contribution of the pairwise addition route in the hydrogenation of propylene amounts to at least 3 %.