Coplanar Pt/C Nanomeshes with Ultrastable Oxygen Reduction Performance in Fuel Cells

Developing highly stable and efficient catalysts toward the oxygen reduction reaction is important for the long-term operation in proton exchange membrane fuel cells. Reported herein is a facile synthesis of two-dimensional coplanar Pt-carbon nanomeshes (NMs) that are composed of highly distorted Pt networks (neck width of 2.05 +/- 0.72 nm) and carbon. X-ray absorption fine structure spectroscopy demonstrated the metallic state of Pt in the coplanar Pt/C NMs. Fuel cell tests verified the excellent activity of the coplanar Pt/C NM catalyst with the peak power density of 1.21 W cm(-2) and current density of 0.360 A cm(-2) at 0.80 V in the H-2/O-2 cell. Moreover, the coplanar Pt/C NM electrocatalysts showed superior stability against aggregation, with NM structures preserved intact for a long-term operation of over 30 000 cycles for electrode measurement, and the working voltage loss was negligible after 120 h in the H-2/O-2 single cell operation. Density-functional theory analysis indicates the increased vacancy formation energy of Pt atoms for coplanar Pt/C NMs, restraining the tendency of Pt dissolution and aggregation.

Automated summary

Efficient and highly stable catalysts for the oxygen reduction reaction are essential for long-term operation of proton exchange membrane fuel cells. The coplanar Pt-carbon nanomeshes synthesized in this study exhibit excellent activity and stability in fuel cell tests, with peak power density of 1.21 W cm(-2) and current density of 0.360 A cm(-2) at 0.80 V in the H-2/O-2 cell. Density-functional theory analysis suggests that the increased vacancy formation energy of Pt atoms in coplanar Pt/C NMs helps restrain Pt dissolution and aggregation.