Atomic-scale restructuring of hollow PtNi/C electrocatalysts during accelerated stress tests

- The structural and compositional changes of hollow PtNi/C nanoparticles during AST were studied.
- The temperature of the AST determines the extent of degradation.
- Hollow PtNi/C nanoparticles are stable at T = 25 °C, start to shrink at T = 57 °C and collapse at T = 80 °C.
- Hollow PtNi/C nanoparticles show higher intrinsic ORR specific activity compared to solid Pt/C.
- The catalytic enhancement is maintained after ageing.