Catalytic Performance of γ-Al2O3–ZrO2–TiO2–CeO2 Composite Oxide Supported Ni-Based Catalysts for CO2 Methanation

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• 作者：Salvatore Abate ; Chalachew Mebrahtu ; Emanuele Giglio ; Fabio Deorsola ; Samir Bensaid ; Siglinda Perathoner ; Raffaele Pirone ; Gabriele Centi
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2016
• 出版时间：April 27, 2016
• 年：2016
• 卷：55
• 期：16
• 页码：4451-4460
• 全文大小：607K
• 年卷期：0
• ISSN：1520-5045

文摘

Composite oxide supported Ni-based catalysts were prepared by a wet impregnation technique and applied to the methanation of carbon dioxide. The composite oxide supports were prepared by an impregnation–precipitation method using commercial γ-Al₂O₃ powder as a host with variation of the percentage of loading of ZrO₂, TiO₂, and CeO₂ promoters from their respective salt precursors. NH₄OH was used as the precipitating agent. The as-prepared catalysts were characterized by Brunauer–Emmet–Teller surface area analysis, atomic absorption spectroscopy, X-ray diffraction, temperature-programmed reduction by H₂ (H₂-TPR), and CO chemisorption. Catalytic activity of the newly synthesized catalysts was investigated toward hydrogenation of CO₂ at atmospheric pressure by varying reaction temperature between 250 and 400 °C (with increasing step equal to 25 °C). Experimental results revealed that the composite oxide supported Ni-based catalysts showed performance superior to that of the γ-Al₂O₃ only supported Ni-based catalyst (which was synthesized using the same procedure for comparison). Among the investigated catalysts, the Ni/C15 catalyst with composite oxide support (55% of γ-Al₂O₃ loading and 15% equivalent loading of ZrO₂, TiO₂, and CeO₂) showed the best activity: 81.4% conversion of CO₂ to CH₄ at 300 °C. Better performance of the composite oxide supported Ni-based catalysts was achieved because of the improvements in the reducibility nature of the catalysts (investigated using H₂-TPR).