Metal-organic frameworks represent one of the most studied options to store hydrogen for clean-energy applications. Nuclear quantum effects, and in particular zero-point energies, are responsible for the reduction up to 20% of hydrogen-uptake levels in porous materials with respect to the unrealistic case of classical hydrogen dynamics. Depending on the theoretical approach describing hydrogen adsorption in metal-organic frameworks, such as including or not nuclear quantum effects, the interaction potential between hydrogen and the host can change dramatically, thus affecting the interpretation of results from computer simulations. We propose an experimental determination, using neutron Compton scattering, of the nuclear quantum effects in the hydrogen adsorption in a test metal-organic framework so as to reconstruct the potential-energy surface affecting hydrogen in a model-free manner.