TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Catalyst: The catalyst contains (in molar % based on total metals) 21.9% Cu, 37.1% Zn and 40.9% Al; 54.3% Cu, 18.7% Zn and 26.6% Al; 50.0% Cu, 43.9% Zn and 5.7% Al; 61.3% Cu, 9.0% Zn and 29.9% Al; 49.8% Cu, 14.6% Zn and 35.4% Al; 48.7% Cu, 17.3% Zn and 33.9% Al; 25.8% Cu, 49.1% Zn and 24.9% Al; or 70.2% Cu, 21.6% Zn and 8.2% Al.Preferred Catalyst Preparation: In step (a) urea is used in a molar ratio to metals of at least 1 (preferably at least 3) and the mixture is heated to 90 degreesC.Preferably the reaction mixture containing the precipitate is stirred for at least 12 hours (specifically 24 hours) at 60-100 degreesC before separation of the precipitate.The washed precipitate is dried at 50-130 degreesC then calcined for 3-5 hours at 300-450 degreesC in presence of air.Preferred Hydrogen Preparation: (A) is used in the form of powder of particle size 0.42-0.59 mm.The catalyst is activated by heating in presence of a reducing gas (preferably hydrogen) at 250-500 degreesC for 1-5 hours, especially using a heating cycle involving increasing the temperature from ambient to 450 degreesC at 3 degreesC per minute, maintaining this temperature for 2 hours and cooling to 110 degreesC.The reactants comprise methanol, oxygen (optionally in the form of air or oxygen-enriched air) and optionally water, the methanol:water:oxygen molar ratio specifically being 1:1.1:0.3 to 1:1.1:0.5.Reaction is carried out at 200-400 degreesC and atmospheric pressure, preferably in an electrically heated tubular reactor. EXAMPLE - Nitrogen (55.2 ml (STP)/minute), oxygen (8.0 ml (STP)/minute) and aqueous methanol (67% methanol/33% water by volume; 3.9 ml (liquid)/h) were passed over a catalyst (A) containing (in molar % based on total metals) 21.9% Cu, 37.1% Zn and 40.9% Al, at 360 degreesC. The conversion of methanol was 94.4%, and the gas leaving the reactor contained 31.1 mol % hydrogen, plus 34.0 mol % nitrogen, 0.4 mol % carbon monoxide, 14.5 mol % carbon dioxide, 19.1 mol % water and 0.9 mol % formaldehyde.