How to take the sample out of a impulse function
From https://es.mathworks.com/help/control/ref/impulse.html "impulse(sys,t) uses the user-supplied time vector t for simulation".

So, just generate your vector as [0:dt:Tfinal] and simulate!

If your system is a rational transfer function, an alternative way would be to compute the residues [r,p,k] = residue(b,a) and just write the time-domain function taking the inverse Laplace transform using whatever time vector you wish.