Triple-phase interfacial engineering Pt-CeO2-nitrogen-doped carbon electrocatalysts for proton exchange membrane fuel cells

Improving the activity and durability of Pt electrocatalysts is an important pathway to reduce the dosage of precious Pt for proton exchange membrane fuel cells (PEMFCs). Herein, zeolitic imidazolate framework-8 (ZIF-8) derived nitrogen-doped carbon (NC) supported Pt-CeO2 composites with abundant triple-phase interfacial conjunction are demonstrated. The CeO2 can modulate the electronic structure of Pt via electronic effects, thus modulating the energy of oxygen intermediates absorbed on Pt sites. Besides, the CeO2 also can stabilize the Pt nanoparticles by metal-support interactions. Therefore, the as-fabricated catalyst shows ultrahigh activity and durability towards oxygen reduction reaction. The half-wave potential is 0.922 V, and mass activity is 0.165 mA.ug(Pt)(-1) in 0.1 M HClO4. After 10, 000 cycles of accelerated durability tests (ADTs), the E-1/2 decreases by only 10 mV. In addition, the 20% Pt/CeO2-NC (power density: 1.08 W.cm(-2), cathode: 0.20 mgPt.cm(-2)) shows more excellent electrochemical activity and durability with lower cathode Pt loading than 20% commercial Pt/C (power density: 1.03 W.cm(-2), cathode: 0.40 mgPt.cm(-2)) in PEMFC single cell measurements. This study provides a novel strategy for constructing a Pt-metal oxide-support triple-phase interface to improve the electrocatalytic performance of catalysts.

Automated summary

In this study, Pt-CeO2 composites supported by zeolitic imidazolate framework-8 (ZIF-8) derived nitrogen-doped carbon (NC) were demonstrated to have abundant triple-phase interfacial conjunction, leading to enhanced activity and durability for the oxygen reduction reaction.