TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: Precipitation in stages (a) and/or (b) is carried out at 20-100 (preferably 40-90, especially 50-70) degreesC and pH 5-11, preferably 5-9.In stage (a) about 50% of the aluminate is added as Al hydroxide sol, and soda solution is used as the alkali, at least in stage (a).Aqueous nitrate or sulfate solutions of Cu, Zn and Al are used in (a) and/or (c), optionally with the addition of salts or oxides of platinum-Group metal(s), Sub-Group IV, V or VI elements or lanthanides.Stage (e) involves washing to an alkali content of not more than 500 ppm, and drying (f) is carried out at between room temperature and 200 degrees C.After calcination, the catalyst is formed into tablets, rings or honeycomb and then at least partly reduced before use.Preferred Catalysts: Catalysts with Cu/Zn atom ratios of:(i) 2.3 +/- 0.3 overall, 0-2.8 in the core and 2.9-3.5 in the outer shell (for methanol synthesis);(ii) 2.0 +/- 0.3 overall, 1.2-1.5 in the core and 0-0.9 in the shell (for low-temperature water gas conversion with high selectivity);(iii) 2.3 +/- 0.3 overall, 2.0-2.5 in the core and 0-1.9 in the shell (for low-temperature water gas conversion with high activity); or(iv) 0.9-2.3 overall, 0-2.0 in the core and 1.2-2.5 in the shell (for hydrogenation and dehydrogenation reactions). EXAMPLE - A mixture of 71 g sodium aluminate, 35 g zinc oxide and 260 g 68% nitric acid was made up to 1 l with water and treated at 64degrees C and pH 7 with aqueous sodium carbonate solution (170 g/l; with stirring; 30 minutes). The suspension obtained was aged for 30 minutes at 60degrees C and then treated at 64degrees C and pH 7 with:    (a) a solution obtained by mixing 77 g zinc oxide, 203 g copper (as Cu nitrate solution) and 160 g 86% nitric acid and making up to 2 l with water; and    (b) an aqueous solution of 170 g sodium carbonate. The second precipitate was aged as before, filtered off, washed with 3 x 20 l water at 60 degrees C (to a sodium content of 350 ppm), dried for 2 hours at 60 degrees C, calcined for 3 hours at 320 degrees C and tabletted with 2 wt% graphite.    The resulting catalyst (Cu/Zn atom ratio = 2.3) was reduced by heating to 235 degrees C in a stream of gas (1.2% hydrogen; 98.8% nitrogen) at 50 l/h and then heated to 250 degrees C in pure hydrogen. When tested in methanol synthesis (using a mixture of nitrogen, carbon mono- and di-oxides and hydrogen at 250 degrees C), the catalyst showed activity values of 1.267, 1.241, 1.221, 1.200 and 1.207 (1.064, 1.075, 1.060, 1.057, 1.070) kg/kg/h after 21, 42, 65, 90 and 113 hours respectively, with an average value of 1.217 (1.065) kg/kg/h; following values at 230degreesC were 0.967 and 0.916 (0.817, 0.795) kg/kg/h after 132 and 156 hours (average = 0.942 (0.806) kg/kg/h); following values at 210 degrees C were 0.396 and 0.382 (0.330, 0.322) kg/kg/h after 179 and 202 hours (average = 0.389 (0.326)); following values at 250 degrees C were 1.151 (1.041) after 224 hours. Values in brackets are for a prior-art catalyst as described in EP 0125689.