TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The catalytic system is of formula (w)(FefMmQqRrOx)asterisk(100 - w)(AlaDdEeOz). It may comprise promoter T, whose quantity t is expressed as mg T metal/kg formulation.(FefMmQqRrOx) = active solid component;w = weight percentage of the active component;Fe, M, Q, R = elements forming the active part;M = Cr and/or Mn;Q = La, lanthanide (e.g. Ce), and/or Zr;R = Al and/or D;x = value required by the oxidation number that the elements Fe, M, Q, R have in the formulation;w = 10-80%, preferably 20-60%;f = 0.5-1, preferably 0.6-1 (atomic fraction);m, q = 0-0.5 (atomic fraction);r = 0-0.1 (atomic fraction);(AlaDdEeOz) = carrier on which the active phase is dispersed;Al, D, E = elements forming the carrier;D = Mg, Ca, Ba, Zn, Ni, Co, Cu, and/or Zn;E = Fe, M, and/or Q;a = 0.625-1, preferably 0.667-0.91 (atomic fraction);d = 0-0.375, preferably 0.09-0.333 (atomic fraction);e = 0-0.1 (atomic fraction);T = Rh, Pt, and/or Pd;t = 1-1000 (preferably 10-500) mg metal/kg formulationPreferred Components: The carrier, before being modified with the active component, corresponds to formula AlaMg(1-a)Oz or AlaZn(1-a)Oz and structurally comprises a compound with a spinel structure indicated as pMgOasteriskAl2O3 (optionally MgO) or pZnOasteriskAl2O3 (optionally ZnO).a = 0.625-0.91 corresponding to a ratio MgO/Al2O3 or ZnO/Al2O3 of 0.2-1.2, preferably 0.667-0.833 corresponding to a ratio MgO/Al2O3 or ZnO/Al2O3 of 0.4-1 Preferred Definitions:    x1 = 20-50;    x2, x3 = 0-10;    x4 = 5-25;    x5 = 50-80    EXAMPLE - A solution containing iron nitrate nonahydrate (650.54 g) was prepared in the volume of water necessary to obtain a 2M solution. Microspheroidal delta-alumina (300 g) was charged into a rotating container. The iron-containing solution was applied with the Impregnation in the Stationary State method. At the end of addition, the damp solid was dried at 120degreesC for a night and thermally treated in a muffle under a light stream of air, with a temperature program including a final step at 800degreesC. The resultant solid contained 30 wt.% FeO1.5 and 70 wt.% AlO1.5.