Oxygen-Doped Carbon Supports Modulate the Hydrogenation Activity of Palladium Nanoparticles through Electronic Metal- Support Interactions

In heterogeneous catalysis, synergies between the metal active phase and oxide support can enhance the catalytic activity through electronic metal-support interactions (EMSI). Such effects are unexpected for conventional carbon supports, and carbon is often viewed as an inert scaffold in catalysis. Here, we demonstrate that carbons do present EMSI that alter the intrinsic rate of palladium atoms near the interface by 200-fold compared to atoms at the apex of 5 nm particles. We also show that oxygen-containing functional groups, which are ubiquitous on carbon surfaces, are responsible for these EMSI. Controlling the scaffold's surface chemistry allowed us to tune its work function from 5.1 to 4.7 eV, the intensity of the charge redistribution at the metal-carbon interface, and the catalytic activity of the corresponding metal atoms. The proposed platform can be applied to fundamentally understand EMSI effects for reactions and carbonaceous supports beyond those studied in the present work.