Abstract: A catalyst comprising, as an active ingredient, one of the following metals: copper, chromium, nickel, cobalt, manganese, zinc, and aluminum, is activated by the reduction of metals with an organic compound as a reducing agent. Such organic compounds as C.sub.8 -C.sub.35 saturated hydrocarbons, C.sub.8 -C.sub.19 unsaturated hydrocarbons, C.sub.8 -C.sub.29 alicyclic hydrocarbons, C.sub.8 -C.sub.10 aromatic hydrocarbons, C.sub.11 -C.sub.13 aliphatic-aromatic hydrocarbons, C.sub.5 -C.sub.30 monohydric alcohols, C.sub.2 -C.sub.6 polyhydric alcohols, phenols, C.sub.7 -C.sub.18 aliphatic aldehydes, C.sub.7 -C.sub.18 aromatic aldehydes, C.sub.7 -C.sub.35 aliphatic ketones, C.sub.6 -C.sub.29 alicyclic ketones, C.sub.2 -C.sub.31 aliphatic carboxylic acids, C.sub.2 -C.sub.31 esters of aliphatic carboxylic acids, aromatic acids, carbohydrates, vegetable oils, animal fats, waxes, polyvinyl alcohols, polyvinyl acetate, polyethylene and polybutadiene, may be used as a reducing agent singly or mixed.