Partial Hydrogenations of Unsaturated Carbonyl Compounds and Unsaturated Hydrocarbons over an Oxidized Amorphous Gold-Zirconium A lloys

Abstract

An amorphous Au-Zr alloy was easily oxidized by treating in a wet atmosphere (H₂O/N₂; partial pressure of H₂O was 40 Pa) and changed into an active catalyst for hydrogenation of unsaturated compounds. The present catalyst system showed high selectivities in hydrogenation of unsaturated carbonyl compounds, especially 2-butenal to 2-butenol. Furthermore, the present catalyst system showed high selectivities (more than 99%) for hydrogenation of unsaturated hydrocarbons, i. e.1, 3-butadiene, propadiene, propyne and 2-methyl-1, 3-butadiene to monoenes. Hydrogenation rate of 1, 3-butadiene was a hundred times faster than that of 1-butene at the same reaction condition. These results show that the present catalyst system has unique active sites in the hydrogenation,
The present catalyst system contained almost no impurities except for 80 ppm of Fe. No condensation of metals was observed on the surface of an oxidized alloy using XPS. We consider that active sites in the present catalyst system are not the sites formed by impurities but by a part of gold which was highly dispersed.