The influence of active carbon as support on the reducibility of supported metals (Ni, Cu, Cd, Zn) has been studied by means
of a temperature programmed reduction (TPR) technique. The TPR profiles indicate that active carbon behaves as a dispersion
agent and the supported metal is dispersed in a disordered phase rather than as a stoichiometric compound. The hydrogen consumed
in the reduction indicates that the metal residues are present in monovalent and divalent forms. High-temperature reduction
peaks were also observed and are explained on the basis of metal-surface interactions and the porosity of the active carbon.
Nitrogen adsorption reveals that the active carbon porosity decreases due to progressive closure of the pores when metals
are supported on the surface of active carbon.