Lewis-acid promoted Au-0 clusters were used as quasihomogeneous or as heterogeneous metal catalysts for the chemoselective hydrogenation of alpha,beta-unsaturated carbonyl compounds. Addition of Lewis-acid cations like Zn2+ to amidic dispersions of size-optimized Au-0 nanocolloids led to an enhanced hydrogenation rate and allylic alcohol chemoselectivity in the hydrogenation of e.g., crotonaldehyde (83% selectivity at 92% conversion). Heterogeneous Au-0 catalysts were generated by the quantitative immobilization of the Au-0 nanocolloids on a nano-sized ZnO support, followed by partial removal of the polyvinylpyrrolidone stabilizer. This deposition preserved the nanodispersed state of Au-0, and resulted in a heterogeneous metal catalyst with stable activity and high C=O chemoselectivity in e.g., the hydrogenation of mesityl oxide (66% selectivity at 91% conversion).