Copper-Based Catalysts for Selective Hydrogenation of Acetylene Derived from Cu(OH)2

Replacing precious metals with cheap metals in catalysts is a topic of interest in both industry and academia but challenging. Here, a selective hydrogenation catalyst was prepared by thermal treatment of Cu(OH)(2) nanowires with acetylene-containing gas at 120 degrees C followed by hydrogen reduction at 150 degrees C. The characterization by means of transmission electron microscopy observation, X-ray diffraction, and X-ray photoelectron spectroscopy revealed that two crystallites were present in the resultant catalyst. One of the crystal phases was metal Cu, whereas the other crystal phase was ascribed to an interstitial copper carbide (CuxC) phase. The reduction of freshly prepared copper (II) acetylide (CuC2) at 150 degrees C also afforded the formation of Cu and CuxC crystallites, indicating that CuC2 was the precursor or an intermediate in the formation of CuxC. The prepared catalysts consisting of Cu and CuxC exhibited a considerably high hydrogenation activity at low temperatures in the selective hydrogenation of acetylene in the ethylene stream. In the presence of a large excess of ethylene, acetylene was completely converted at 110 degrees C and atmospheric pressure with an ethane selectivity of <15%, and the conversion and selectivity were constant in a 260 h run.

Automated summary

In this study, a selective hydrogenation catalyst was prepared by thermal treatment of Cu(OH)(2) nanowires and hydrogen reduction, resulting in the formation of Cu and CuxC crystallites. Characterization revealed that CuC2 was the precursor or intermediate in the formation of CuxC. The catalyst exhibited high hydrogenation activity for acetylene in the ethylene stream at low temperatures, with consistent conversion and selectivity over a long period of operation.