Selective Transfer Semihydrogenation of Alkynes with H2O (D2O) as the H (D) Source over a Pd‐P Cathode. (9th September 2020)

• Record Type: Journal Article
• Authors: Wu, Yongmeng; Liu, Cuibo; Wang, Changhong; Lu, Siyu; Zhang, Bin
• Is Part Of: Angewandte Chemie. Volume 132:Number 47(2020)
• Page Start: 21356
• Page End: 21361
• Publication Date: 2020-09-09
• Subjects: alkynes -- deuteration -- electrocatalysis -- Pd-P nanostructures -- semihydrogenation; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202009757
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: We reported a selective semihydrogenation (deuteration) of numerous terminal and internal alkynes using H2 O (D2 O) as the H (D) source over a Pd‐P alloy cathode at a lower potential. P‐doping caused the enhanced specific adsorption of alkynes and the promoted intrinsic activity for producing adsorbed atomic hydrogen (H*ads ) from water electrolysis. The semihydrogenation of alkynes could be accomplished at a lower potential with up to 99 % selectivity and 78 % Faraday efficiency of alkene products, outperforming pure Pd and commercial Pd/C. This electrochemical semihydrogenation of alkynes might proceed via a H*ads addition pathway rather than a proton‐coupled electron transfer process. The decreased amount of H*ads at a lower potential and the more preferential adsorption of the Pd‐P to C≡C π bond than C=C moiety resulted in the excellent alkene selectivity. This method was capable of producing mono‐, di‐, and tri‐deuterated alkenes with up to 99 % deuterium incorporation. Abstract : Pd‐P nanostructures are efficient electrocatalysts for selective semihydrogenation (deuteration) of terminal and internal alkynes using H2 O (D2 O) as the H (D) source at a lower potential via an adsorbed atomic hydrogen (H*ads ) addition pathway. P‐doping causes enhanced specific adsorption of alkynes and promoted intrinsic activity for producing H*ads from water electrolysis.