Photocatalytic oxidation of ethylene by ammonium exchanged ETS-10 and AM-6

Abstract

ETS-10 and AM-6 in the as-prepared and ammonium form have been characterized using Raman, X-ray powder diffraction, N2 adsorption, energy dispersive X-ray (EDX) analysis, UV/vis spectroscopy, and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Upon NH4+ ion exchange, AM-6 shows the loss of the characteristic V–O–V stretch in the Raman spectrum similar to the effects observed for NH4+ ion exchanged ETS-10. The UV/vis spectrum of NH4+ ion exchanged AM-6 also shows similar changes to NH4+ ion exchanged ETS-10, though the band gap in AM-6 is not red shifted as it is in ETS-10. Heating the NH4+ exchanged AM-6 to form H-AM-6 changes the coordination environment of the vanadium from an octahedral coordination to a tetrahedral coordination, but does not cause the partial collapse of the AM-6 structure. The oxidation of ethylene under oxygen on as-synthesized AM-6 only produces partial oxidation products while the NH4+ ion exchanged AM-6 was able to completely oxidize ethylene to CO2.