If the e-cat is unambiguously validated, there will be a lot of research projects started to see if the effect is unique to nickel, or if the same effect can be achieved with cheaper metals like aluminum.
If I were going to look, my first choice would be titanium. It spontaneously forms hydrides somewhat like nickel and palladium do. Follow-up would be nickel/titanium alloys/composites. Pretty much everything I've read says "whatever" it is that is going on happens at "dislocations" (cavities, grain boundaries) in the solid substrate. The more "dislocations", the higher the reactivity. Right now, my mental picture is something along the lines of "electron holes" that form in semiconductors.