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 °C followed by hydrogen reduction at 150 °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 (Cu x C) phase. The reduction of freshly prepared copper (II) acetylide (CuC2) at 150 °C also afforded the formation of Cu and Cu x C crystallites, indicating that CuC2 was the precursor or an intermediate in the formation of Cu x C. The prepared catalysts consisting of Cu and Cu x C 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 °C and atmospheric pressure with an ethane selectivity of <15%, and the conversion and selectivity were constant in a 260 h run.

A high‐performance base metal catalyst for acetylene selective hydrogenation was prepared from cupric subcarbonate (Cu2(OH)2CO3) by thermal treatment with an acetylene‐containing gas followed by hydrogen reduction. The characterization results revealed that the copper catalyst was composed of interstitial copper carbide (CuxC) and metal Cu, which were embedded in porous carbon matrix. The CuxC crystallites, which showed outstanding hydrogenation activity, were derived from the hydrogen reduction of copper (II) acetylide (CuC2) which was generated from the reaction between acetylene and Cu2(OH)2CO3. The Cu particles and porous carbon were generated from the unavoidable thermal decomposition of CuC2. The prepared Cu‐derived catalyst completely removed the acetylene impurity in an ethylene stream with a very low over‐hydrogenation selectivity at 110 °C and atmospheric pressure. No obvious deactivation was observed in a 180‐h test run. In the Cu‐derived catalyst, CuxC served as the catalytic site for H2 dissociation, Cu mainly functioned as the site for selective hydrogenation of acetylene, whereas the porous carbon matrix posed a steric hindrance effect on the chain growth of linear hydrocarbons so as to suppress the undesired oligomerization.

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