Effect of the Charge State on the Catalytic Activity of a Fullerene-Based Molecular Electrocatalyst: A Theoretical Study

The charge state of a catalyst is significant for its catalytic activity. In this work, taking molecular electrocatalysts of fullerene C-60 with a doped transition metal (TM-C-60, where TM = Fe, Co, or Ni) as an example, we conducted first-principles calculations to study the effect of the charge state on the cathodic nitrogen reduction reaction (NRR) and anodic oxygen evolution reaction (OER). Our calculated results suggest that the maximal free energy barrier of the NRR with a dissociative mechanism is a nearly linear function of the number of negatively charged electrons (0-3). Nevertheless, the NRR activity with an associative mechanism is insensitive to the charge state effect. The OER activity of TM-C-60 with a 0-3 e(+) charge state exhibits a volcano-shaped trend, which indicates that it is important to tailor a particular charge state toward effective catalytic activity. This study provides new insight into the effect of the charge state on catalytic activity, which could help us improve our understanding of the catalytic mechanism and tailor a new efficient catalyst.