Optimizing the Electronic Structure of Ordered Pt–Co–Ti Ternary Intermetallic Catalyst to Boost Acidic Oxygen Reduction

Abstract

Developing advanced electrocatalysts toward the sluggish oxygen reduction reaction (ORR) kinetics is critical to fuel cells but still an enormous challenge at present. Here, we demonstrate a highly active and durable Pt-based ternary catalyst, ordered Pt3Co0.6Ti0.4 intermetallic nanoparticles (∼3 nm) supported on ZIF-8-derived mesoporous carbon (Pt3Co0.6Ti0.4/DMC). The Pt3Co0.6Ti0.4/DMC catalyst exhibits faster ORR kinetics compared to Pt3Co/DMC and commercial Pt/C with minimal activity loss (20.1%) and only 5 mV decay in half-wave potential after 20,000 potential cycles. More importantly, its improved performances have also been proven in the H2/air PEM single cell test. The theoretical calculations reveal that the substitution of Ti for Co induces a strengthened ligand effect and optimizes the surface electronic structure of Pt3Co0.6Ti0.4, resulting in the significantly enhanced ORR activity. This work provides a reliable and promising approach for the development of efficient and robust Pt-based ternary intermetallic electrocatalysts for practical fuel cell applications.