Application of nickel catalysts in the system combining catalytic reaction with membrane separation

A system combining catalytic reaction with membrane separation was used to prepare p-aminophenol from p-nitrophenol. In this system, nickel powder catalysts in suspension were employed during reaction and then separated from slurry by an inorganic membrane filter. The working efficiency of this system depends decisively on the hydrogenation rate and membrane flux, therefore, they should be considered comprehensively. In this study, the nano-sized nickel catalysts prepared by chemical reduction (CR) have higher activity than the nickel catalysts prepared by physical vapor deposition (PVD) due to the former have larger active specific surface area. During membrane separation, the steady permeate flux in filtration of nano-sized nikel catalysts with high reactivity is smaller than that in filtration of micro-sized nickel catalysts with low reactivity. When the nano-sized nikel catalysts and the micro-sized nickel catalysts were mixed together, not only flux can be improved effectively but also a higher catalytic activity can be achieved. This study makes a contribution to the industrial application of the system combining catalytic reaction with membrane separation.