Contribution of Oxide Supports in Nickel-Based Catalytic Elimination of Greenhouse Gases and Generation of Syngas

Abstract

Carbon dioxide and/or dry methane reforming serves as an effective pathway to mitigate these greenhouse gases. This work evaluates different oxide supports including alumina, Y-zeolite and H-ZSM-5 zeolite for the catalysis of dry reforming methane with Nickel (Ni). The composite catalysts were prepared by impregnating the supports with Ni (5%) and followed by calcination. The zeolite supported catalysts exhibited more reducibility and basicity compared to the alumina supported catalysts, this was assessed with temperature programmed reduction using hydrogen and desorption using carbon dioxide. The catalytic activity, in terms of CH4 conversion, indicated that 5 wt% Ni supported on alumina exhibited higher CH4 conversion (80.5%) than when supported on Y-zeolite (71.8%) or H-ZSM-5 (78.5%). In contrast, the H-ZSM-5 catalyst led to higher CO2 conversion (87.3%) than Y-zeolite (68.4%) and alumina (83.9%) supported catalysts. The stability tests for 9 h time-on-stream showed that Ni supported with H-ZSM-5 had less deactivation (just 2%) due to carbon deposition. The characterization of spent catalysts using temperature programmed oxidation (O2-TPO), X-ray diffraction (XRD) and thermo-gravimetric analysis (TGA) revealed that carbon deposition was a main cause of deactivation and that it occurred in the lowest degree on the Ni H-ZSM-5 catalyst.

Keywords

• CO₂
• CH₄
• stability
• H-ZSM-5
• carbon deposition
• greenhouse gas reduction