Palladium nanoparticles supported on ceria thin film for capillary microreactor application

Ceria thin film in capillary microreactor was developed as a catalyst support for palladium nanoparticles (Pd NPs) by sol–gel approach. The thickness of Pd/CeO₂ film deposited in capillary of 250 μm internal diameter is 200 nm as measured by scanning electron microscope (SEM), and the particle size of Pd NPs as determined by the transmission electron microscope (TEM) images is 4.2 nm. The Pd/CeO₂ immobilized capillary was tested for hydrogenation of phenylacetylene in a microreactor at temperature range of 30–60 °C. Higher selectivity toward ethylbenzene was recorded at higher temperature. The reaction rate of 1.89 × 10⁻³ mol g⁻¹ s⁻¹ was obtained for 158 ppm phenylacetylene hydrogenation at 60 °C and 0.50 ml min⁻¹ hydrogen flow rate. The ceria thin film was stable even after 6 days.