The Mentos explosion reaction is more physical than chemical. Diet soda is used because the dissolved sugar in regular soda tends to keep the Carbon dioxide in solution.

The Mentos tends to break the surface tension and also provide a physical surface for the reaction

H2CO3 (aq) — H2O (l) + CO2 (g)

to go very rapidly. Any carbonated diet soda will work.

The key is that it must be a diet drink with carbonation.
The sugar in the mentors causes the carbonation to come out of solution creating the gas pressure.

drinks with sugar have much less carbonation and can not be released so quickly.