  We investigate the thermodynamic behaviour of the four dimension Gauss Bonnet
black hole, proposed in [Phys. Rev. Lett. 124, 081301 (2020)], in the AdS
background . We study the thermodynamics in extended phase space, where the
cosmological constant is taken as the thermodynamic pressure. The black hole
exhibits a phase transition similar to that of van der Waals system. The phase
transition is investigated via isotherms in $P-V$ diagram, Gibbs free energy
and specific heat plots. The charged and neutral cases are considered
separately to observe the effect of charge on critical behaviour. In both cases
the van der Waals like behaviour is exhibited. We also study the throttling
process of the black hole analytically using isenthalpic and inversion curves.
