Structurally ordered intermetallic platinum–cobalt core–shell nanoparticles with enhanced activity and stability as oxygen reduction electrocatalysts

Abstract

To enhance and optimize nanocatalyst performance and durability for the oxygen reduction reaction in fuel-cell applications, we look beyond Pt-metal disordered alloys and describe a new class of Pt-Co nanocatalysts composed of ordered Pt(3)Co intermetallic cores with a 2-3 atomic-layer-thick platinum shell. These nanocatalysts exhibited over 200% increase in mass activity and over 300% increase in specific activity when compared with the disordered Pt(3)Co alloy nanoparticles as well as Pt/C. So far, this mass activity for the oxygen reduction reaction is the highest among the Pt-Co systems reported in the literature under similar testing conditions. Stability tests showed a minimal loss of activity after 5,000 potential cycles and the ordered core-shell structure was maintained virtually intact, as established by atomic-scale elemental mapping. The high activity and stability are attributed to the Pt-rich shell and the stable intermetallic Pt(3)Co core arrangement. These ordered nanoparticles provide a new direction for catalyst performance optimization for next-generation fuel cells.

Mesoporous hybrid material composed of Mn3O4nanoparticles on nitrogen-doped graphene for highly efficient oxygen reduction reaction

“…1 Currently, Pt-based materials are considered as the most active ORR catalysts, but their low tolerance to methanol, scarcity of resources and high cost prevent them to be a sustainable solution to low efficient ORR. 2 Therefore, extensive efforts have been undertaken toward development of durable and 20 low cost substitutes with comparable ORR activity to that of commercial Pt/C materials. These efforts are mainly focused on the metal-free catalysts and non-precious metal materials.…”

Elemental Anisotropic Growth and Atomic-Scale Structure of Shape-Controlled Octahedral Pt–Ni–Co Alloy Nanocatalysts

“…So a number of reports have dealt with Pt-based ternary alloy nanoparticles for ORR [29][30][31], , but none has put effort in tailoring their morphological shape [32][33][34] . Now, on the basis of previous studies, Pt-Co binary alloy catalysts also exhibit high activity and stability [35][36][37][38] and for that reason, spherical PtNiCo ternary alloys have attracted more attention as a family of ORR catalysts that would allow tuning both ORR activity and stability [39][40][41][42] . However, synthetic control of their shape and composition as well as atomic-scale knowledge and control over the spatial distribution of the metal atoms across the NCs has remained elusive.…”

RhCu 3D Nanoframe as a Highly Active Electrocatalyst for Oxygen Evolution Reaction under Alkaline Condition

“…A great improvement in this area has been feasible with facet‐controlled nanoparticles and core–shell nanoparticles with lattice mismatch, which enables surface‐energy modulations 10, 11, 12, 13, 14, 15, 16, 17. Most notably, phenomenal enhancement in catalytic performance has been accomplished by framework nanostructures with dramatically increased surface area per volume, and a great deal of current interest resides on the design and synthesis of novel nanoframework structures 18, 19, 20, 21, 22, 23.…”