Plasma assisted catalytic dry reforming of methane (DRM) over metal organic frameworks (MOFs) based catalysts
Abstract Plasma assisted dry reforming of methane (DRM) was performed in a dielectric barrier discharge (DBD) reactor. The effect of different packing materials including ZrO2, UiO 67 MOF and PtNP@UiO 67 on plasma discharge was investigated, showing that ZrO2 suppressed the plasma generation while UiO 67 improves it due to its porous nature which favours the formation of filamentary microdischarges and surface discharges. The improved plasma discharge increased the conversion of CH4 and CO2 by about 18% and 10% respectively, compared to the plasma alone mode. In addition, the distribution of hydrocarbon products changed from dominant C2H6 in the plasma alone mode to C2H2 and C2H4 in the UiO 67 promoted plasma assisted DRM. The UiO 67 MOF was stable in plasma, showing no significant changes in its properties under different treatment times, discharge powers and gases. Pt nanoparticles (NPs) on UiO 67 improved plasma assisted DRM, especially the selectivity due to the presence of surface reactions. Due to the dehydrogenation of hydrocarbons over Pt NPs, the selectivity to hydrocarbons decreased by 30% compared to the UiO 67 packing. In situ diffuse reflectance infrared Fourier transformed spectroscopy (DRIFTS) was carried out to probe the surface reactions on PtNP@UiO 67 catalyst, showing the decomposition of surface formats to CO and C2H4 dehydrogenation over the metallic Pt. The PtNP@UiO 67 catalyst showed good reusability in the plasma assisted DRM, and H2 production was improved by high CH4/CO2 molar ratio and low feed flow rate.