Highly active palladium nanocatalyst for selective hydrogenation of 1,5-cyclooctadiene under atmospheric H₂ pressure

An ionic liquid [CH₃(OCH₂CH₂)₂₂N⁺Et₃][p-CH₃C₆H₄SO₃⁻] was synthesized and employed for stabilizing Pd nanocatalyst, which possesses the thermoregulated phase-separable property. The as-prepared Pd nanocatalyst was applied for the selective hydrogenation of 1,5-cyclooctadiene under atmospheric H₂ pressure. The >99% conversion of 1,5-cyclooctadiene with 95% selectivity towards cyclooctene was achieved under the optimal reaction conditions. The Pd nanocatalyst could be reused for six cycles without evident loss in conversion and selectivity. The turnover frequency of 4232 h⁻¹ is greater than those of previously reported Pd nanocatalyst under atmospheric H₂ pressure.