(532dr) Ti55Cx(x=38,44)@Pt92 Cuboctahedral Core-Shell Nanoclusters for Oxygen Reduction Reaction: A DFT Study

Developing a highly efficient catalyst with low Pt content for the oxygen reduction reaction is highly sought for fuel cell applications. The potential applicability of a carbide-based core-shell (Ti55Cx@Pt92, x=38,44) nanoclusters (NCs) toward ORR activity is investigated and compared with that of a pure Pt NC (Pt147) and transition metal based Ti55@Pt92 NC. The thermodynamic stability and dissolution potential of Ti55Cx@Pt92 (x=38,44) NCs are investigated for their possible synthesis and practical usages. Rate-determining step (*OH formation) and overpotential of Ti55Cx@Pt92 (x=38,44) NCs are highly improved when compared to the cuboctahedral Pt NC (Pt147). Our detailed investigation reveals that the charge redistribution is the key factor for stabilizing platinum shell and improving catalytic activity by adjusting to optimal adsorption behaviors of reaction intermediates. Synthesis of inexpensive TiC cores and the stability of core-shell nanoclusters open promising design strategies using earth-abundant material to develop low-cost, ultradurable core-shell catalysts.