TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Catalyst: The catalyst support may also comprises an oxide consisting of alumina, ceric oxide or zirconia or a mixture of at least two of these. The catalyst may also include a promoter element P which is an alkali or alkaline earth or rare earth of atomic number 57 - 71, the content being 0 - 5 % of the total catalyst mass. The active phase comprises one or two metal from group VIII of content between 0.01 - 20 % ; the metal(s) may be noble, with a content of 0.2 - 5 %. or preferably non-noble(Ni, Co or Fe) with content of 1 - 10 %. A treatment is effected to eliminate any chlorine present due to the use of a chlorinated precursor, consisting of a calcination at high temperature in the presence of water, or by washing at ambient temperature with an ammoniacal solution to give a residual Cl content of a few ppm. The vapour reforming process is carried out at 500 - 800 degrees C, 0.1 - 3 MPa and a VVH of 10000 - 80000 h-1; the molar ratio water / ethanol being 0.8 - 10. The vapour reforming may also be effected in combination with a partial oxidation in the presence of O2 with a ratio O2 / ethanol of 0.1 - 1.8. EXAMPLE - (7) Catalytic evaluation of the reforming of ethanol at atmospheric pressure : 0.5 g of catalyst was mixed with 2.75 g of silicon carbide and placed in a tubular stainless steel reactor. This was fed with a mixture of EtOH and water at a gaseous velocity GHSV of 13400 h-1. The pressure was 1 bar absolute, temperature 700 degrees C and molar ratio H2O ; EtOH = 4. Before testing, the catalysts were precalcined in air for 4 hours at 700 degrees C and activated in a H2 flow at 500degreesC for 15 hours. The catalysts tested were as follows :- Catalyst A(comparison) : Contained 0.22 % of Rh on alumina of surface area 130 m2/g with a Rh dispersion of 51 % ; no M or M' metals were present. Catalyst B(invention) : Prepared in two stages; firstly, preparation of a spinel support from solutions of magnesium nitrate and aluminum nitrate, then deposition of rhodium nitrate. The prepared catalyst contained 5 % Mg, as MgAl2O4 and 0.2 % Rh ; the dispersion of Rh was 49 %. Catalyst D(invention) : During preparation of the spinel phase, a co-impregnation of magnesium nitrate and nickel nitrate was effected to produce a phase of composition Ni0.75Mg0.25Al2O4 (Ni + Mg) = 5 % of support. Rh was then deposited as above. The prepared catalyst contained 3.8 % Ni, 1.3 % Mg and 0.19 % Rh ; the dispersion of Rh was 48 %. The gaseous effluents from the trials were analysed by GLC and the following results obtained: Catalyst A ; selectivity in H2 : 60.9 % ; conversion of EtOH : 84 % ; Catalyst B : selectivity in H2 : 68.2 % ; conversion of EtOH : 100 % ; Catalyst D : selectivity in H2 : 68.7 % ; conversion of EtOH : 98.3 % ; Catalysts B and D thus give improved performances for similar dispersion of Rh.