Can an alloy catalyst change during a reaction?

I am studying the reaction pathway of oxygen evolution reaction (OER) on a PtNi alloy catalyst using density functional theory (DFT). What I found is that, for different intermediates, the most stable configuration of the PtNi(111) surface can be different. Let's say I have a $2\times2$ cell, and the most stable surface composition for the HO\* intermediate is Pt$\_4$, whereas for the O\* intermediate, the most stable surface composition is Pt$\_3$Ni (O\* attached to Ni). My question is as follows:


Is the alloy catalyst allowed to change during the reaction? If we consider the reaction step HO\* → O\*, the easiest way is to assume the catalyst doesn't change during the reaction. However, if the energy barrier of the reaction is lowered so much when O\* bonds Ni that it compensates the energy barrier of swapping a surface Pt atom with a subsurface Ni atom, does it suddenly become favorable? I think it comes down to comparing one large energy barrier vs. two small energy barriers, but I can't find any theories regarding this. Any suggestion is appreciated.


