A recent study by Dr. Yuanyue Liu and his team, published in The American Chemical Society (ACS), has revealed a previously overlooked catalytic site in M–N–C materials, which are vital for energy conversion reactions like the oxygen reduction reaction (ORR). Traditionally, M–N–C catalysts feature pyridinic sites as the primary active sites.
However, the researchers discovered a second catalytic site at the edges of the graphene sheet or along its pores.
Using Fe–N–C as an example, the team identified this site as a hybrid structure combining pyridinic and porphyrinic features and exhibited comparable activity to the pyridinic site. The existence of this site was supported by X-ray adsorption and stability simulations. They also found that this site is present in other M–N–C materials with different metal elements.
This discovery paves the way for site engineering in M–N–C catalysts, potentially enhancing their performance in ORR and other energy reactions. This marks a key advancement for improving catalytic performance. This work was performed by Dr. Yuanyue Liu and his Ph.D. students Zachary Levell, Saerom Yu, and Ruoyu Wang.
Read more at: https://pubs.acs.org/doi/10.1021/jacs.4c12479
