From rotating disk electrode to single cell: Exploration of PtNi/C octahedral nanocrystal as practical proton exchange membrane fuel cell cathode catalyst

摘要

PtNi/C octahedral nanocrystal catalyst is prepared through surfactant-assisted solvothermal approach using cetyltrimethylammoniurn bromide as structure directing agent, and its performance on rotating disk electrode and membrane electrode assembly are investigated through experiment and simulation. Its mass activity and specific activity at 0.9 V vs. RHE are about 6.1 and 6.6 times high of commercial Pt/C, respectively. The membrane electrode assembly that is fabricated using PtNi/C octahedral catalyst in cathode exhibits enhanced power generation performance and durability. Its cell voltage at 1000 mA cm(-2) is increased by 34 mV compared with the control, and its maximum power densities are raised by 160.2 mW cm(-2) and 0.27 kW g(P)(t)(-1). After 100 h galvanostatic durability test, the attenuation rates of its cell voltage at 1000 mA cm(-2) and maximum power density are 6.9% and 14.3% (10.9% and 18.4% for the control), respectively. The simulation results also reveal that PtNi/C octahedral catalyst not only has high half cell performance, but also shows actual application potential in single cell, which demonstrates the feasibility that the excellent performance of PtNi/C octahedral catalyst at rotating disk electrode level can be realized in single cells through optimization of membrane electrode assembly fabrication and cell operation conditions.