Oxidative Dry Reforming of Methane to Syngas on a Ni/Al2O3 Catalyst

In order to develop an industrially viable catalyst for dry reforming of methane (DRM), an Al₂O₃ supported Ni catalyst was prepared by the incipient wet impregnation method. Unfortunately, catalyst deactivation was pronounced in such non-noble metal catalysts due to coking and sintering. As the active metal interaction with the underlying support is pivotal in catalyst performance, the Ni/Al₂O₃ catalyst was calcined at 850°C. The resulting H₂-TPR profile suggested a strong metal-support interaction since a reduction peak maxima was observed at 752°C. The catalyst was also characterized by UV-vis, XRD, surface area and H₂-chemisorption. The DRM reaction was performed in a packed bed tubular reactor with a molar feed composition of CH₄:CO₂:N₂ = 1:1:1. Partial oxidation of methane (POM) was also investigated for syngas production. The molar feed composition was kept as CH₄:O₂:N₂ = 1:x:2-x, where x was 0.08, 0.15, or 0.225. The spent catalysts were qualitatively and quantitatively characterized by FESEM, XPS and CHNO analysis. A comparative study of the activity test suggested that Ni/Al₂O₃ performed better for DRM compared to POM, and lower coking was observed. To obtain an even better performance, the DRM was coupled with POM, such that the ratio of the reactants was CH₄:CO₂:O₂:N₂ = 1:1:x:1-x. The combined DRM and POM reaction resulted in an energetically efficient oxidative dry reforming of methane (ODRM) reaction with minimal carbon formation. Thus, ODRM emerged as an efficient syngas production route with amplified catalyst activity and with minimal formation of carbon-whiskers for x = 0.225.