CO2 conversion efficiently catalyzed under ambient conditions by new self-supported and recyclable Cu2S

Abstract

The catalytic activation of CO₂ under mild conditions to form value-added heterocyclic products is of paramount interest. Copper sulfides are a large class of materials, many of which are found as minerals in nature. They often show remarkable physical properties, and further studies of their catalytic properties need to be conducted. The simple compound Cu₂S was designed, its synthesis was improved, and its catalytic activities in CO₂ activation are disclosed here. Synthesized Cu₂S is shown to be an efficient heterogeneous catalyst for the carboxylation of propargylamines under ambient temperature and pressure conditions and the carboxylation of terminal alkynes under one atm CO₂ at 80 °C. CO₂ is transformed into high-value-added chemicals with a wide range of substrates with excellent yields, and the catalyst is easily reused at least 5 times without significant activity reduction. The catalytic and recycling performances are significantly better for synthesized Cu₂S compared to those of its commercial analogue. In summary, Cu₂S is a new catalyst that is simple, non-toxic, self-supported, recyclable, and practical. These findings open a general route to the catalytic properties of Cu₂S toward, not only mild CO₂ activation applications, but also a variety of other useful reactions.