I am learning adding alkyl groups to benzene using Fridel-Crafts alkylation:
I know that it is very common to use $\ce{AlCl3/AlBr3}$ as Lewis acid catalyst in this reaction. But I am just wondering whether I can use a Bronsted acid, e.g., $\ce{H2SO4}$, as the catalyst or not. For example, in a $\mathrm{E1}$ or hydration reaction, $\ce{H2SO4}$ is added to alkene or alcohol, respectively, forming a carbocation, which is the same ultimate result when $\ce{AlCl3}$ is used (make the alkyl group more electrophilic).
I am thinking $\ce{AlCl3}$ is the only way if I am adding primary alkyl halide since in $\mathrm{E1}$/hydration reactions, an actual primary carbocation is impossible to be formed (too unstable), while it exists in a complex with $\ce{AlCl3}$ (not entirely a carbocation, so can be formed).
SO, what is the problem with secondary/tertiary alcohols if I use the Bronstad acid? If there is a problem, way? Both Lewis and Bronsted acid ways will lead to carbocation rearrangements (I have not learnt the acylation).