Selective C=C Hydrogenation of Unsaturated Hydrocarbons in Neat Water Over Stabilized Palladium Nanoparticles Via Supported 12-Tungstophosphoric Acid
- 14 Downloads
Stabilized Pd(0) nanoparticles by supported 12-tungstophosphoric acid (Pd(0)-TPA/ZrO2) was explored as a sustainable recyclable catalyst for selective C=C hydrogenation of cyclohexene and crotonaldehyde. The catalyst shows an outstanding performance [catalyst to substrate ratio (1:1.31 × 104)] towards high conversion as well as 100% selectivity of the desired product with high turnover number (> 10,000) and turnover frequency (> 2600 h−1) for both the systems. The use of neat water as a solvent and mild reaction conditions makes the present system environmentally benign and green. Moreover, the catalyst could be recovered and reused up to five cycles without any significant loss in their conversion as well as selectivity. The viability of the catalyst was evaluated towards different aromatic as well as aliphatic arenes and found to be excellent in all the cases. The obtained selectivity, especially butyraldehyde, was correlated with the nature of the catalyst as well as solvent and based on the study, a plausible mechanism for both the reactions was also proposed.
KeywordsSelective C=C hydrogenation Crotonaldehyde Cyclohexene Neat Water Pd nanoparticles Supported 12-tungstophosphoric acid
We are thankful to Department of Atomic Energy (DAE) and Board of Research in Nuclear Science (BRNS), Project No. 37(2)/14/34/2014-BRNS, Mumbai, for the financial support. One of the authors Mr. Anish Patel is thankful to the same for the grant of JRF. We are also thankful to Department of Chemistry, The Maharaja Sayajirao University of Baroda for BET surface area analysis.
Compliance with Ethical Standards
Conflict of interest
There are no conflicts to declare.
- 5.Puskas R, Sápi A, Kukovecz Á, Kónya Z (2016) Understanding the role of post-CCVD synthetic impurities, functional groups and functionalization-based oxidation debris on the behaviour of carbon nanotubes as a catalyst support in cyclohexene hydrogenation over Pd nanoparticles. RSC Adv 6:88538–88545CrossRefGoogle Scholar
- 10.Özkar S, Finke RG (2016) Palladium(0) nanoparticle formation, stabilization, and mechanistic studies: Pd(acac)2 as a preferred precursor, [Bu4 N]2HPO4 stabilizer, plus the stoichiometry, kinetics, and minimal, four-step mechanism of the palladium nanoparticle formation and subsequent agglomeration reactions. Langmuir 32:3699–3716CrossRefGoogle Scholar
- 17.Li Y, El-Sayed MA (2001) The effect of stabilizers on the catalytic activity and stability of Pd colloidal nanoparticles in the suzuki reactions in aqueous solution. Org Lett 105:8938–8943Google Scholar