In the attempt to reduce the high-cost and improve the overall durability of Pt-based electrocatalysts for the oxygen reduction reaction (ORR), density-functional theory (DFT) calculations have been performed to study the energetics of the elementary steps that occur during ORR on TiN(100)- and TiC(100)-supported single Pt atoms. The O2 and OOH* dissociation processes on Pt/TiN(100) are determined to be non-activated (i.e. "barrier-less" dissociation) while an activation energy barrier of 0.19 and 0.51eV is found for these dissociation processes on Pt/TiC(100), respectively. Moreover, the series pathway (which is characterized by the stable OOH* molecular intermediate) on Pt/TiC(100) is predicted to be more favorable than the direct pathway. Our electronic structure analysis supports a strong synergistic co-operative effect by these non-oxide supports (TiN and TiC) on the reduced state of the single-atom Pt catalyst, and directly influences the rudimentary ORR steps on these single-atom platinized supports.
Tak, Y. J., Yang, S., Lee, H., Lim, D. H., & Soon, A. (2018). Examining the rudimentary steps of the oxygen reduction reaction on single-atomic Pt using Ti-based non-oxide supports. Journal of Industrial and Engineering Chemistry, 58, 208-215. https://doi.org/10.1016/j.jiec.2017.09.027