Fabrication of porous copper/manganese binary oxides modified ZSM-5 membrane catalyst and potential application in the removal of VOCs

Copper-manganese binary oxides modified ZSM-5 membrane catalysts were synthesized by using incipient wetness impregnating method. Specifically, the PSSF (paper-like sintered stainless steel fibers) support was fabricated by wet lay-up papermaking/sintering process and the ZSM-5 membranes were synthesized on the surface of stainless steel fibers by using secondary growth process. The catalysts were characterized by using scanning electron microscopy (SEM), Energy dispersive X-ray spectrometer (EDS) mapping, X-ray diffraction (XRD), N2 adsorption–desorption, X-ray photoelectron spectra (XPS) as well as H2-TPR (Temperature programmed reduction). The most efficient catalyst was Cu–Mn(1:6)/ZSM-5/PSSF, exhibiting best catalytic activity (% of isopropanol conversion was 210 °C) and excellent reaction rate. It can be also demonstrated that the zeolite membrane reactor performs better for isopropanol oxidation, giving a T90% that is around 70 °C lower than obtained in the traditional particles fixed bed. The excellent catalytic performance of the Cu–Mn(1:6)/ZSM-5/PSSF catalysts can be attributed to the presence of ZSM-5 zeolite membrane, well dispersion of catalysts actives, reasonable mass/heat transfer efficiency, excellent oxygen storage ability as well as higher contacting efficiency. Furthermore, the Cu–Mn(1:6)/ZSM-5/PSSF catalyst exhibits a high stability after being used at 260 °C for 50 h.