Electrochemical Grafting of a Pyridinium-Conjugated Assembly on Graphite for H2O2 Electrochemical Production

Carbon materials have shown great promise as cost-effective electrocatalysts for H2O2 electrochemical production. In this work, we prepare a series of well-defined pyridinium-conjugated graphite sheets via nucleophilic substitution reaction of graphite with pyridine derivatives in anodic oxidation process. A combination of experimental and computational investigations confirm that the pyridine derivatives are electrochemically grafted onto the armchair-type edges of graphitic layers, where the adjacent carbon atoms show the positively charged state by the intramolecular charge transfer. The strong charge delocalization on pyridinium-conjugated graphite sheets leads to the enhanced electrocatalytic performance for oxygen reduction in terms of both activity and selectivity (above 97 %) for H2O2 production. Moreover, we find that the yield of H2O2 is also affected by the H2O2 decomposing capabilities of functional groups on pyridinium. As one kind of pyrolysis-free strategies, the proposed electrochemical grafting can serve as a molecularly precise regulation to develop nitrogen doped carbon materials for more applications.