Direct Bonding of CpCo- Fragments on Pt Nanoparticles and their Electronic Effect for Alkyne Semihydrogenation

Additives are commonly used to improve the catalytic performance of supported metal nanoparticles. However, depositing additives with a clear structure, location, and composition remains challenging. Herein, we report the bonding of cobaltocene fragments (CpCo-) on Pt nanoparticles via a self-limiting way like atomic layer deposition. The electron density of Pt increases after the formation of the stable CpCo-Pt bond and is quantitatively controlled by the CpCo- coverage. The higher Pt electron density originates from the d orbital of Co and π-orbital of Cp. As a result of the electronic effect of the CpCo-, the adsorption of olefins on the Pt surface is weakened and activation energy for C═C bond hydrogenation increases, resulting in high selectivity in alkyne semihydrogenation. Our method can be further utilized to precisely tailor the electronic structure of active species for enhanced catalytic performance by sample changing the type of the fragments.