Balancing Competing Reactions in Hydride Transfer Catalysis via Catalyst Surface Doping: The Ionization Energy Descriptor

Hydride
transfer (HT) is ubiquitous in catalytic reduction reactions.
In heterogeneous electrocatalysis, the hydride donor could be a molecular
catalytic intermediate adsorbed on an electrode surface. The stability
and hydride-donating capability of such an intermediate may determine
overall catalytic efficiency. Here, we report how to fine-tune a hydride
donor’s performance via doping an electrode surface. For semiconductor
electrodes, we find that the ionization energy of the surface dopant
can serve as a good descriptor for both the stability and hydride-donating
capability of the catalytic intermediate adsorbed on the doped site.
For the specific case of CO2 reduction on p-GaP, where
adsorbed 2-pyridinide (2-PyH–*) was predicted to
be the most likely hydride-donating species, we predict that its catalytic
performance should be particularly enhanced by substituting Ga with
Ti on the electrode surface; Sc, Al, and V surface dopants also could
be worthy of further investigation.