Pt-Co nanoparticles anchored by ZrO2 for highly efficient and durable oxygen reduction reaction in H2-air fuel cells

Synthesis of Pt-based catalysts with high activity and durability for oxygen reduction reaction (ORR) remains a very challenging task in the field of fuel cells. Here, Co-doped Pt nanoparticles (NP) with surface-defect ZrO2 are supported on the multi-walled carbon nanotubes (MWCNTs) (denoted as PteCo thorn ZrO2/MWCNTs). The PteCo thorn ZrO2/MWCNTs displays an ORR mass activity of 0.98 A mgPt(-1) at 0.9 V, which is 4.1-fold higher than that of the commercial Pt/C (0.238 A mgPt(-1)). Further durability test shows that the PteCo thorn ZrO2/ MWCNTs remains nearly unchanged ORR mass activity after 50000 accelerated durability testings (ADTs). Based on the mass performance and surface performance, the fuel cell with PteCo thorn ZrO2/MWCNTs cathode has far better power performance than that with commercial Pt/C. Moreover, the fuel cell with PteCo thorn ZrO2/MWCNTs cathode undergo only a 6.1% maximum power loss after 50000 ADTs. However, that with commercial Pt/C cathode after 30000 ADTs has 39.6% maxinum power loss. More impressively, compared to the 220 mV loss of Pt/C after 30000 ADTs, the PteCo thorn ZrO2/MWCNTs cathode also displays only 20 mV loss at 0.8 A/cm(2) after 50000 ADTs. The enhanced intrinsic activity of Pt eCo thorn ZrO2/MWCNTs may be attributed to the Co-doped Pt NPs and interface effect of Codoped Pt NPs and surface defect-rich ZrO2. (C) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.