Preparation of lower polyhydric alcohols

In a process for the preparation of a lower polyhydric alcohol by catalytic hydrogenolysis of sucrose in an aqueous medium, at elevated temperatures and pressures, the improvement for selectively producing ethylene glycol and 1,2-propylene glycol which comprises:

• using a catalyst in which the active material consists essentially of a reduced mixture of the oxides of the metals cobalt, copper and manganese, containing at least 5 up to not more than 80% by weight of manganese and up to not more than 85% by weight of copper, the percentages being based upon a total content of said metals of 100%, said catalyst being prepared by mixing the relevant metals in the form of their aqueous salt solutions and precipitating them together from this mixture by adding a base, then isolating and drying the precipitated material and converting the dried precipitate by calcination into a mixed oxide which is subsequently activated by reduction with hydrogen at an elevated temperature of at least about 200.degree. C.;
• and
• carrying out the hydrogenation reaction at a temperature of from 220.degree. C. to 280.degree. C. and at a hydrogen pressure of from 250 to 700 bar.