Hydrogen is the molecule of choice for the moderation of cold neutrons at international facilities. It manifests itself in one of two different forms: a state with nuclear spins parallel to each other (orthohydrogen, oH), and one with the nuclear spins anti parallel (parahydrogen, pH). Cold neutrons experience destructive interference when scattering from pH, a phenomenon largely suppressing the neutron cross section, a fundamental feature to optimise time pulses of moderated neutrons. Neutron facilities generally use catalysts to speed up the conversion of oH into pH, as the natural conversion rate would require weeks in order to obtain high levels of pH. This experiment will shed light onto the catalytic conversion phenomena by obtaining a map of the pH concentration around the catalyst, a piece of information that will allow optimisation, for example, of neutron moderators.