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Palladium Supported on Fluorite Structured Redox CeZrO 4‐δ for Heterogeneous Suzuki Coupling in Water: A Green Protocol
Author(s) -
Burange Anand S.,
Shukla Rakesh,
Tyagi Avesh Kumar,
Gopinath Chinnakonda S.
Publication year - 2016
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201600655
Subject(s) - catalysis , palladium , redox , chemistry , fluorite , suzuki reaction , particle size , dispersion (optics) , leaching (pedology) , heterogeneous catalysis , metal , chemical engineering , inorganic chemistry , organic chemistry , physics , environmental science , soil science , optics , soil water , engineering
Pd on redox CeZrO 4‐δ catalysts was prepared, characterized and their activity was evaluated for Suzuki coupling reaction in water under reflux condition. Fresh and reduced form of 5 % Pd (R−Pd5) on CeZrO 4‐δ catalyst exhibited 100 % conversion in 2.5 and 1 h, respectively. R−Pd5 shows significant activity for wide range of substrate compatibility and for less reactive aryl bromides too. The mechanistic investigations proved the important role of redox CeZrO 4‐δ support on the catalytic activity. It was observed that the presence of oxygen vacancy along with Ce 3+ enhances the activity. 1 wt % Pd photodeposited on pre‐reduced CeZrO 4‐δ support requires a mere 20 min. for 100 % conversion of Suzuki coupling. Effect of metal dispersion and particle size on catalytic activity is also discussed. High Pd dispersion with small particle size (4±1 nm), particle size preservation after reaction, strong metal‐support interaction and no leaching fully suggest the heterogeneous mechanism is operative for Suzuki coupling on 1 wt % Pd photodeposited on reduced CeZrO 4‐δ support. Present work hints the possibility of achieving high conversion for Suzuki reaction with very small amount of Pd through better dispersion by taking advantage of redox support and in water.