Sn-containing Heusler alloy catalysts promote alkyne coupling during phenylacetylene hydrogenation.

Heusler alloy catalysts containing Sn exhibited characteristic side reactions during phenylacetylene hydrogenation. Product analysis indicated that the major identifiable by-products were diphenylbutadiene isomers. The results suggest that Sn-containing Heusler alloys facilitate alkyne coupling as a side reaction, leading to the formation of C16 species, including diphenylbutadiene isomers.