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

Abstract

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 H2/O2 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 H2/O2 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.

Oxygen Reduction Electrocatalysts toward Practical Fuel Cells: Progress and Perspectives

“… [54] Recently, a two‐dimensional coplanar PtCo alloy reported excellent ORR activity at single cell. The coplanar Pt‐carbon nanomesh demonstrates a peak power density of 1.21 W cm −2 and current density of 0.36 A cm −2 at voltage of 0.80 V in H 2 /O 2 cell, where the interconnected Pt network separated by the coplanar carbon avoids aggregation and migration of Pt revealing higher durability under realistic fuel cell conditions [115] . DFT investigations demonstrate that coplanar Pt surface is covered by the graphitic layer, with the higher vacancy formation energy than the clean Pt, hence the more difficult Pt vacancy formation for the covered Pt boosts the durability of the catalyst.…”

Superfast Synthesis of Densely Packed and Ultrafine Pt–Lanthanide@KB via Solvent‐Free Microwave as Efficient Hydrogen Evolution Electrocatalysts

“…[ 26 ] The vacancy formation energy ( E V‐Pt ) of the outermost Pt atoms represents the tendency of dissolution of Pt atoms. [ 11a ] In Figure a, the E V‐Pt of Pt 61 La 39 @KB (1.466 eV) is higher than Pt/C (2.08 eV), which indicates that the formation of a Pt vacancy from Pt 61 La 39 @KB is more difficult than Pt/C. The higher E V‐Pt is, the harder it is to dissolve Pt and retard the dissolution of other atoms at the same time, supporting the excellent durability of Pt 61 La 39 @KB.…”

“…[ 10 ] Meanwhile, the long‐term stability of Pt/C is another potential problem due to the virtue of premature decay during electrocatalytic process. [ 11 ] Therefore, the rational design of Pt‐based catalysts with high activities, good stabilities, and less expensive is needed to enable low‐cost hydrogen production in water splitting.…”

Bimetal-organic framework-derived carbon nanocubes with 3D hierarchical pores as highly efficient oxygen reduction reaction electrocatalysts for microbial fuel cells

“…The experimental data indicate that compared with Pt/C, Mes-C-N-Zn90Co10 as a cathode catalyst can generate a competitive voltage, showing it has potential application prospects in MFCs that stably operate for a long time. This potential is mainly because micropores contribute to exposing the active areas, and mesopores help O 2 adequately diffuse to the active sites [50][51][52][53]. The hierarchically porous framework formed by the combination of micropores and mesopores contributes to enhancing the ORR catalytic activity and MFC-cathode power output performance.…”