« on: 28/04/2020 22:20:05 »
(plus most catalysts don't actually work just as well in both directions)Yes they do.
Catalytic cycles with multiple elementary steps don't have to work equally well in both directions.
O2 + 4 H+ + 4 e– → 2 H2O (oxygen reduction reaction, or ORR)
2 H2O → O2 + 4 H+ + 4 e– (oxygen evolution reaction, or OER)
It was noted that Ir/C has poor ORR activity, but good OER activity whereas Pt/C exhibited excellent ORR activity, but very low OER activity.https://www.sciencedirect.com/science/article/abs/pii/S092633731730735X
If you had a catalyst that favoured one reaction, but not the other, it would change the position of equilibrium and you could make a "free energy" machine.
Not if you have to push it both ways...