Surface hydrogenation of oxygen terminated MXenes M2CO2 (M = Ti, V, Nb)

•The potential of hydrogen pair interactions on the MXenes M2CO2 surface (M = Ti, V, Nb) is always repulsive.•Nearest-neighbour repulsions negatively correlate with the lattice parameter.•Repulsions between second-nearest neighbours is weaker than between third-nearest.•Due to lateral interactions hydrogen adlayer on considered MXenes features ordered phases with 1/3 and 2/3 ML coverage and varying thermal stability.•In atmospheric air at normal conditions it is expected that Nb2CO2 has near-zero hydrogen coverage, while on V2CO2 and Ti2CO2 hydrogen adlayer should form ordered phase with 1/3 ML coverage.