Multi-Component PtFeCoNi Core-Shell Nanoparticles on MWCNTs as Promising Bifunctional Catalyst for Oxygen Reduction and Oxygen Evolution Reactions

The development of commercially viable fuel cells and metal air batteries requires effective and cheap bifunctional catalysts for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). Multi-component Pt-Fe-Co-Ni nanoparticles on multi-walled carbon nanotubes (MWCNTs) were synthesized by wet chemistry route via NaBH4 reduction of metal salts, followed by sintering at different temperatures. The catalyst demonstrates an excellent ORR activity and a promising OER activity in 0.1 m KOH, with a bi-functional overpotential, ΔE of 0.83 V, which is comparable to the values of Pt/C or RuO2. Furthermore, it shows outstanding long-term stability in ORR and OER, namely diffusion limited current density at a potential of 0.3 V decreased just by 5.5% after 10000 cycles in ORR. The results of the PFCN@NT300 indicate a significant effect of the substitution of Pt by the transition metal (TM) and the formation of nanoparticles on the catalytic performance, especially in the OER.

具备商业化应用潜力的燃料电池与金属空气电池的研发，亟需兼具高效性与低成本的双功能催化剂，用于氧还原反应（oxygen reduction reaction, ORR）与氧析出反应（oxygen evolution reaction, OER）。本研究通过湿化学合成路线制备了多壁碳纳米管（multi-walled carbon nanotubes, MWCNTs）负载的多组分Pt-Fe-Co-Ni纳米颗粒：先以硼氢化钠（NaBH₄）还原金属盐，随后在不同温度下进行烧结处理。该催化剂在0.1 mol/L KOH电解液中展现出优异的ORR活性与颇具应用前景的OER活性，其双功能过电位ΔE为0.83 V，性能可与铂碳（Pt/C）或二氧化钌（RuO₂）相媲美。此外，该催化剂在ORR与OER测试中表现出出色的长期稳定性：在ORR测试中，0.3 V电位下的扩散极限电流密度在10000次循环后仅下降了5.5%。对PFCN@NT300的测试结果表明，过渡金属（transition metal, TM）对Pt的取代以及纳米颗粒的形成对催化性能具有显著影响，这一影响在OER测试中尤为突出。