Hydrogen spillover through the gas phase was investigated, using a reactor, with a separate activation compartment, containing the catalyst (metal/alumina), and a reaction compartment with graphite or activated carbon, both separated by a frit. The only product, methane, was analyzed, using GC. In presence of catalyst the formation rate of methane was clearly above the limit of detection in contrast to measurements without catalyst. Different structure of the metal (Pt, Ni, Rh, and Pt-Ni), obtained under helium or hydrogen lead to great differences in the reaction rates.