Seed‐mediated Growth of AlloyedAg‐PdShells toward Alkyne Semi‐hydrogenation Reactions under Mild Conditions^†

Abstract

Main observation and conclusion Ag@Ag‐Pdx core‐shell nanocomposites with various Ag/Pd ratio were deposited on Ag nanoplates using a seed growth method. When physically loaded on C3N4, Ag@Ag‐Pd0.077/C3N4 with optimized Ag/Pd ratio could accomplish high catalytic performance for the semi‐hydrogenation of phenylacetylene as well as other aliphatic (both terminal and internal alkynes) alkynes and phenylcycloalkynes containing functional groups (such as ester, hydroxyl, ethyl groups) under room temperature and 1 atm H2. The alloying and ensemble effects are used to interpret such catalytic performance.

Understanding the Reactivity, Selectivity, and Deactivation of Frustrated Lewis Pairs for Semihydrogenation of Acetylene

“…Research efforts have sought to control the shape of Pd nanoparticles, 17 prepare isolated single-atom catalysts, 18−22 modify the supports, 23−33 alloy Pd with a second metal, 34−38 use organic modifiers, 39,40 or use bimetallic dual-site catalysts. 41,42 Although significant progress has been achieved, new catalysts predominantly use expensive noble metals (e.g., Pd, 18−40 Pt, 43 Ru, 44 Rh, 42 Au, 38 and Ag 35 ) and their related alloys with gaseous hydrogen (H 2 ) or expensive and/or toxic organic hydrogen sources. Thus, these alternatives raise new concerns pertaining to cost, safety, and sustainability.…”

“…However, its disadvantagesthe high cost of Pd, the low selectivity to alkene, and the potential harm to the environment and human health if lead is introduced into the waste streammotivate research efforts to replace Lindlar’s catalyst. Research efforts have sought to control the shape of Pd nanoparticles, prepare isolated single-atom catalysts, − modify the supports, − alloy Pd with a second metal, − use organic modifiers, , or use bimetallic dual-site catalysts. , Although significant progress has been achieved, new catalysts predominantly use expensive noble metals (e.g., Pd, − Pt, Ru, Rh, Au, and Ag) and their related alloys with gaseous hydrogen (H 2 ) or expensive and/or toxic organic hydrogen sources. Thus, these alternatives raise new concerns pertaining to cost, safety, and sustainability.…”