A Low-Temperature Carbon Encapsulation Strategy for Stable and Poisoning-Tolerant Electrocatalysts

Carbon encapsulation is an effective strategy for enhancing the durability of Pt-based electrocatalysts for the oxygen reduction reaction (ORR). However, high-temperature treatment is not only energy-intensive but also unavoidably leads to possible aggregation. Herein, a low-temperature polymeric carbon encapsulation strategy (approximate to 150 degrees C) is reported to encase Pt nanoparticles in thin and amorphous carbonaceous layers. Benefiting from the physical confinement effect and enhanced antioxidant property induced by the surface carbon species, significantly improved stabilities can be achieved for polymeric carbon species encapsulated Pt nanoparticles (Pt@C/C). Particularly, a better antipoisoning capability toward CO, SOx, and POx is observed in the case of Pt@C/C. To minimize the thickness of the catalyst layer and reduce the mass transfer resistance, the high mass loading Pt@C/C (40 wt%) is prepared and applied to high-temperature polymer electrolyte membrane fuel cells (HT-PEMFCs). At 160 degrees C, a peak power density of 662 mW cm(-2) is achieved with 40% Pt@C/C cathode in H-2-O-2 HT-PEMFCs, which is superior to that with 40% Pt/C cathode. The facile strategy provides guidance for the synthesis of highly durable carbon encapsulated noble metal electrocatalysts toward ORR.

Automated summary

This study presents a low-temperature carbon encapsulation strategy to enhance the durability of Pt-based electrocatalysts for the oxygen reduction reaction, improving stability and resistance to poisoning gases. By minimizing catalyst layer thickness and reducing mass transfer resistance, high mass loading Pt@C/C was successfully prepared and applied in high-temperature polymer electrolyte membrane fuel cells, achieving a peak power density of 662 mW cm(-2) at 160 degrees C.