Copper integrative catalytic pairs with mixed-valence Cu<sup>2+</sup>-Cu<sup>3+</sup> Species for selective alkyne conversion.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41168185.
- Also identified by DOI 10.1038/s41467-025-64639-w and PMC identifier 12575668.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Achieving specific orbital activation of C ≡ C by controlling the precise atomic architecture of supported metals is crucial for the selective transformation of alkynes. However, its physical mechanism remains a subject of debate. Herein, we construct a well-defined O-bridged CuN<sub>3</sub>-O-CuN<sub>3</sub> integrative catalytic pairs (Cu ICPs) based on Kirkendall effect. As a result, Cu ICPs with mixed Cu<sup>2+</sup>-Cu<sup>3+</sup> species demonstrate >99% conversion and >550 h stability in acetylene hydrochlorination (simulated industrial reaction conditions), showcasing unparalleled performance in the liquid-phase hydrochlorination of five alkynes as well. A combined experimental and theoretical analyses reveal selective coupling between the d<sub>xz</sub>/d<sub>yz</sub> orbitals of Cu ICPs and the σ orbitals of C ≡ C in C<sub>2</sub>H<sub>2</sub>, leading to the formation of highly reactive di-σ-HC = CH intermediate. Additionally, the presence of the bridged-O species promotes HCl dissociation, altering the addition pathway from the classical Eley-Rideal (E-R) mechanism to a Cl•-trigged Langmuir-Hinshelwood (L-H) mechanism, ultimately reducing the intrinsic energy barrier for addition, and breaking the universal standard electrode potential linear scaling relations.