External Mass Transfer Performance Studies in a Micropacked Bed Reactor with Pd/PDA/Nickel Foam

The coating materials of monolithic foam catalysts have a remarkable influence on the mass transfer and reaction process of packed bed reactors. However, the external mass transfer performance of micropacked bed reactors (μPBRs) based on the organic polymer-coated foam catalyst has not been investigated. This study explores the α-methylstyrene hydrogenation reaction and external mass transfer performance of μPBRs with a polydopamine (PDA)-coated foam catalyst. Pd/PDA/nickel foam has excellent α-methylstyrene hydrogenation activity and stability compared to Pd/Al2O3/nickel foam in μPBRs. The effect of pressure, gas and liquid superficial velocities, and pore size of foam packing on external mass transfer coefficient ((ka)OV) was investigated. The (ka)OV of the PDA-coated foam packing can reach 0.31–1.03 s–1, which shows a notable improvement over the Al2O3 coating. Furthermore, an empirical correlation equation for (ka)OV in μPBRs with PDA-coated foam packing is developed to provide a foundation for further design optimization and industrial applications.