Selection of materials for cleaning gases formed in electrolysis

This article examines the catalytic properties of commercial nickel-bearing catalysts in reactions that oxidize CO and o-cresol. The temperature and oxygen content of the gas being cleaned are definitively established along with the choice of materials for synthesizing suitable catalysts and supports. Removing CO and resinous substances containing more than 1 g/m 3 , dust, hydrogen fluoride, and the impurity SO 2 from the anodic gases formed in electrolysis operations is a challenge from both a scientific and a technical standpoint. Catalytic combustion is the most promising technology for this purpose, but its implementation hinges on the resolution of several issues: • the materials chosen for the support and the catalytically active component must be chemically stable in media containing HF; • it must be empirically demonstrated that the chosen materials are highly catalytically active in relation to CO and the resinous substances, which are condensed aromatic compounds; • it is necessary to ensure that the catalyst for SO 2 is not highly susceptible to poisoning; • it is necessary to determine the optimum temperature and minimum concentration of oxygen in the electrolysis gases so as to allow for efficient use of the catalyst.