In this manuscript, the authors reported an extensive suite of ex situ, in situ, operando, and post mortem techniques to study platinum nanoalloys at key stages of their development. This finding demonstrates that local lattice distortion, rather than global strain and ligand effect, governs both the activity and durability of the catalyst under operating conditions. This is pretty interesting work. However, there are still some problems to be solved. After minor revisions, this article can be accepted for publication. The detailed comments are listed as follows.
1. The manuscript refers to the Methods section in multiple places, but the detailed synthesis procedures and experimental methods are not provided in the Supporting Information.
2. The microstrain and SD are closely related to the ORR activity. How are the values of microstrain and SD in Table S1 calculated from WAXS? Please provide the detailed calculation formulas.
3. In Figure 3e, why do some catalysts exhibit two oxidation peaks while others do not? What do these two oxidation peaks represent, respectively? Why is the peak at 0.7 V associated with the presence of grain boundaries rather than being assigned to CO oxidation?
4. The authors suggest that local lattice distortion determines the activity and durability of the catalyst. How can one design more efficient ORR catalysts based on local lattice distortions?
5. What characterization techniques can be used to probe local lattice distortions besides WAXS?