producer means in addition to the air intake 109 comprises the oil supply line 110 and a gas supply line 112 as well as a multitude of catalytic substances which are schematically suggested only as boxes which can be similarly constructed as the catalysts 103 of the deno x converter the catalytic conversion of oil or natural gas into cracked gas can thereby take place even by the utilization of the same active catalytic material i e the specific lanthanum cobalt metal oxide coatings as proposed for the deno x reaction in further embodiment of the invention an especially hard material such as for instance the already mentioned cordierite can be utilized as carrier material for the active metal coating however it should be made especially porous in order to ensure a complete impregnation of the material with the solution of lanthanum and cobalt salts or generally expressed the salts forming the active metal coating layer the catalytic substance is thereby made in two stages in the first stage by means of impregnation a salt containing al or al and mg is put into the finely porous material and subsequently is thermally or chemically decomposed this results in the formation of a catalytic support coating of u03b3 or u03b1 al 2 o 3 or a spinel of mgo and al 2 o 3 washcoat upon which the catalyst is then impregnated in a second step this is.