Abstract: A hydrogenation catalyst composition useful for the hydrogenation of an oxalate diester, said composition being composed of a reduction product of a copper-containing silica gel formed by contacting an amine complex of copper with silica gel having an average particle diameter of not more than 200.mu. and a process for producing the aforesaid composition. Using a catalyst composed of the aforesaid composition, ethylene glycol and/or a glycolic acid ester can be produced from an oxalate diester efficiently with high conversions and selectivities and without causing pollution attributed to the use of a chromium-containing catalyst composition.

Abstract: A hydrogenation catalyst composition useful for the hydrogenation of an oxalate diester, said composition being composed of a reduction product of copper-containing silica gel formed by contacting an ammine complex of copper with colloidal silica sol; and a process for producing the aforesaid composition. Using a catalyst composed of the aforesaid composition, ethylene glycol and/or a glycolic acid ester can be produced from an oxalate diester efficiently with high conversions and selectivities and without causing pollution attributed to the use of a chromium-containing catalyst composition.

Abstract: In a process for producing ethylene glycol and/or a glycollic acid ester by the vapor phase catalytic hydrogenation of an oxalic acid diester in the presence of a catalyst and hydrogen gas, the improvement wherein the catalyst has the following composition formulaCuMo.sub.k Ba.sub.p O.sub.qwherein k, p and q represent gram-atoms of Mo, Ba and O, respectively, per gram-atom of Cu, k is a number of from 0 to 3, p is a number of from 0 to 6, and q is a number determined depending upon the atomic valence and gram-atoms of Cu, Mo and Ba, provided that k and p are not zero at the same time; and the aforesaid catalyst.

Abstract: A hydrogenation catalyst composition for use in the hydrogenation of a lower alkyl ester of a lower hydroxycarboxylic acid. The composition is composed of a reduction product of copper-containing silica gel formed by contacting an ammine complex of copper with silica gel having an average particle diameter of not more than 200 microns or colloidal silica sol. A process for producing the catalyst composition is also provided. By using the aforesaid catalyst composition, a lower alkylene glycol can be produced efficiently in high conversions and selectivities without causing pollution attributed to the use of a chromium-containing catalyst composition.

Abstract: A hydrogenation catalyst composition useful for the hydrogenation of an oxalate diester, said composition being composed of a reduction product of copper-containing silica gel formed by contacting an amine complex of copper with colloidal silica sol; and a process for producing the aforesaid composition. Using a catalyst composed of the aforesaid composition, ethylene glycol and/or a glycolic acid ester can be produced from an oxalate diester efficiently with high conversions and selectivities and without causing pollution attributed to the use of a chromium-containing catalyst composition.

Abstract: In a process for producing a glycollic acid ester by the vapor phase catalytic hydrogenation of an oxalic acid diester in the presence of a catalyst and hydrogen gas, the improvement wherein the oxalic acid diester in the vaporous state is contacted with hydrogen gas in the presence of a catalyst composed of Ag or Pd supported on a solid carrier at a temperature of from about 120.degree. C. to about 300.degree. C.