Synthesis and application of palladium stearates as precursors for the preparation of palladium nanoparticles

• Published in: Applied organometallic chemistry 2012-12, Vol.26 (12), p.736-742
• Main Authors: Yen, Clive H., Wei, Hui-Hsien, Lin, Hsin-Wei, Tan, Chung-Sung
• Format: Article
• Language: English
• Subjects: catalysts; hydrogenation; nanoparticles; organosols; palladium
• ISSN: 0268-2605; 1099-0739
• DOI: 10.1002/aoc.2925

This report successfully demonstrates the synthesis and application of palladium stearates. It was found that the branching of the carboxylate anion of metal precursors could influence the size and shape of palladium nanoparticles (PdNPs). Worm‐like nanowires were formed when using the branched isomer palladium isostearate (PdISt2), while triangular nanoparticles were produced in a majority when using the normal form: palladium stearate (PdSt2). Furthermore, when applying CO2 to the system, both types of PdNPs transformed into more spherical shapes with smaller sizes. The formation of carbamates from the amine stabilizer with CO2 could prevent the further growth and aggregation of PdNPs. The PdNPs were tested as catalysts for the hydrogenation of styrene, and higher catalytic activities were achieved with PdNPs that were prepared with the assistance of CO2. Copyright © 2012 John Wiley & Sons, Ltd. Branching effect of the carboxylate anions could lead to different sizes and shapes of the Pd nanoparticles. Smaller, more spherical and more uniform size distribution of Pd nanoparticles could be obtain by the addition of CO2, and the Pd organosols exhibit high catalytic activities in the hydrogenation of styrene to ethylbenzene.