catalyst有咩用~~~?

(不好意思唔識用中文答,我讀e.m.i.學校)
Catalyst can speed up the rate of reaction with itself chemically unchanged, by providing an alternative mechanism for the reaction with a much lower activation energy, so that the activation energy barrier can be more easily overcome.

所以呢...冇用nickel咪可能要高一點的温度才能造town gas囉,因為activation energy大左.

想補充一點:
catalyst 唔一定 speed up the rate of reactions. But the majority are.
They only change the rate of reaction.