The grand canonical Monte Carlo simulations of proton binding at the energetically heterogeneous metal oxide/electrolyte interface are presented. Special attention is focused on the surface topography: distribution of adsorption sites on the surface and adsorption energy among these sites. In addition to the patchwise and random topographies of adsorption energy distributions, the geometrically correlated topography (generalized Gaussian model) is tested. The adsorption isotherms appear to be extremely dependent on the assumed topography; however, this effect becomes complex if we include long-range interactions. So, the two models, one neglecting lateral interactions and another taking them into account, are considered.