Selective hydrogenation of acetylene over Ni-Zn-P catalysts supported on polyureihane foam

Abstract

In the present work, cheap metals were studied as alternative catalysts in the selective hydrogenation of acetylene. The Ni-Zn-P catalysts supported by polyurethane foam were prepared by electroless deposition method with various zinc salt contents in the deposition bath (6-24 g/l ZnSO4.7H2O). The amounts of Ni and P in the bath were fixed at 42 g/l NiSO4.6H2O and 24 g/l NaH2PO2, respectively. From the deposition rate, compression test, SEM and EDX results, increasing amount of Zn in the bath resulted in lower rate of metal deposition. The catalyst prepared with amount of Zn 18 g/l showed the best dispersion on PU foam as well as the highest Zn/Ni ratio and the highest amount of Zn obtained in the final catalysts at 27.3 wt% with Ni and P 65.2 and 7.5 wt%, respectively. Such catalyst also exhibited the best catalyst performances in terms of acetylene conversion and ethylene selectivity. Further improvement of the Ni-Zn-P catalysts can be obtained using the Al2O3 supports in the order: Ni-Zn-P/-Al2O3 pellet > Ni-Zn-P/-Al2O3 powder > Ni-Zn- P/PU foam (Zn 18 g/l).