Catalysts in the form of grains of which > 90% by weight have a particlesize < 10 micrometres, consisting of a mixture of oxides on a magnesiumsilicate support, containing by weight > 20% but < 35% of copper and > 2% but < 3% of bismuth and of an apparent specific gravity of > 0,2 but < 1,0
Supported catalysts, n.e.s. (excl. supported catalysts with precious metal, a preciousmetal compound, nickel or a nickel compound as the active substance and catalysts in the form of grains of which > 90% by weight have a particlesize < 10 micrometres, consisting of a mixture of oxides on a magnesiumsilicate support, containing by weight > 20% but < 35% of copper and > 2% but < 3% of bismuth and of an apparent specific gravity of > 0,2 but < 1,0)