Well-controlled Pt–CeO2–nitrogen doped carbon triple-junction catalysts with enhanced activity and durability for the oxygen reduction reaction

Abstract

Reducing the usage of Pt for the oxygen reduction reaction (ORR) is of great significance for the commercialization of proton exchange membrane fuel cells. Herein, a triple-junction interface of Pt–CeO₂–nitrogen doped carbon (Pt–CeO₂–NC) has been demonstrated by regulating the density of dispersed CeO₂ nanocrystals on the NC support which effectively avoids the sole contact between Pt and CeO₂ or the NC support. CeO₂ nanocrystals in the Pt–CeO₂–NC triple-junction with a high concentration of oxygen vacancies can modulate the chemical state of Pt, and tightly anchor Pt nanoparticles via strong metal–support interactions, as well as guarantee electron transfer between Pt and the NC support. The well-controlled Pt–CeO₂–NC triple-junction catalyst exhibits excellent activity and stability in acidic media with a mass activity of 593.6 mA mg_Pt⁻¹ (6.1 times that of commercial Pt/C) and a 5 mV decline of half-wave potential after 10 000 cycles of accelerated durability testing, which is superior to the results for reported Pt/CeO₂ catalysts in previous studies. This work highlights the importance of Pt-oxide-support triple-junctions for developing highly efficient Pt electrocatalysts.