How to increase the selectivity of Pd-based catalyst in alkynol hydrogenation: Effect of second metal

Artur Yarulin, Igor Yuranov, Fernando Cárdenas-Lizana, Duncan T L Alexander, Lioubov Kiwi-Minsker*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

53 Citations (Scopus)


The development of selective Pd-based catalyst for semi-hydrogenation of dehydroisophytol (DIP), a C20-alkynol, is reported. A series of unsupported mono- (Pd) and bimetallic (Pd-M) nanoparticles (NPs) with Pd/M molar ratios of 1.5 - 5.0 (M = Ag or Cu) were examined as model systems. The Pd-Ag and Pd-Cu NPs with controlled crystal sizes of ∼3.3 nm were prepared by Ag (Cu) electroless deposition on pre-formed poly(N-vinyl-2-pyrrolidone)-stabilized Pd0 colloids. Bimetallic Pd-Ag NPs adopted a core (Pd)-shell (Ag) structure whereas a mixed alloy was attained in the Pd-Cu nanocrystals. A (partial) Pd surface segregation induced by reaction with H2 was in evidence for the Pd-Ag NPs. A significant increase in selectivity up to 97% (at XDIP = 99%) to the target alkenol was demonstrated following the incorporation of a second metal. This result is attributed to the dilution of the surface Pd-sites by Ag (Cu) and a modification of the Pd electronic properties. Pd-Ag NPs, having shown the highest selectivity, were further deposited on a structured support based on sintered metal fibers (SMF) coated with ZnO. The improved selectivity achieved over the unsupported Pd-Ag colloidal NPs was retained over the structured catalytic system. The bimetallic Pd 5.0Ag/ZnO/SMF (SIP = 93%) demonstrated a drastic increase in IP selectivity relative to the monometallic Pd/ZnO/SMF (SIP = 78%) and state-of-the-art Lindlar catalyst (SIP = 62%) at DIP conversion ≥99% with the stable activity during 50 h, suggesting catalyst feasibility for selective semi-hydrogenation of long chain alkynols with important applications in the manufacture of vitamins and fine chemicals.

Original languageEnglish
Pages (from-to)186-193
Number of pages8
JournalApplied Catalysis A: General
Publication statusPublished - 20 May 2014


  • Dehydroisophytol
  • Isophytol
  • Partial hydrogenation
  • Pd nanoparticles
  • Pd-Ag
  • Pd-Cu
  • Sintered metal fibers
  • ZnO

ASJC Scopus subject areas

  • Catalysis
  • Process Chemistry and Technology


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