Steam reforming of acetic acid over Ni/ZrO2 catalysts: Effects of nickel loading and particle size on product distribution and coke formation

• Published in: Applied catalysis. A, General Vol. 417-418; pp. 281 - 289
• Main Authors: Li, Zhikun, Hu, Xun, Zhang, Lijun, Liu, Shaomin, Lu, Gongxuan
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 29.02.2012; Elsevier
• Subjects: Acetic acid; Catalysis; Chemistry; Coke formation; Exact sciences and technology; General and physical chemistry; Ni/ZrO2 catalyst; Nickel loading; Steam reforming; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Ni/ZrO2 catalyst; Coke formation; Steam reforming; Acetic acid; Nickel loading; Methane; Binary compound; Particle size; Methanation; Hydrogen; Coke; Active site; Decomposition; Selectivity; Zirconium oxide; Carboxylic acid; Water gas; Transition element compounds; Polymerization; Transition metal; Ketone; Coke deposition; Heterogeneous catalysis; Distribution; Nickel; Ni/ZrO; By product; Catalyst; Acetone
• ISSN: 0926-860X; 1873-3875
• DOI: 10.1016/j.apcata.2012.01.002

[Display omitted] ► Ni loading significantly affects reducibility and particle size of Ni species in Ni/ZrO2. ► Ni (16wt.%)/ZrO2 catalyst presents the superior catalytic activity, selectivity and stability. ► Ni (≤13wt.%)/ZrO2 shower higher selectivity to the organic by-products. ► Ni (≥20wt.%)/ZrO2 catalysts favor production of CO, CH4 and the coke formation. Steam reforming of acetic acid has been carried out over a series of Ni/ZrO2 catalysts to measure the effects of nickel loading on distribution of the reforming products and coke formation. Ni (≤13wt.%)/ZrO2 catalysts do not contain enough active metal sites for steam reforming of both acetic acid and organic by-products. Ni (≥20wt.%)/ZrO2 catalysts can effectively catalyze steam reforming but lack selectivity, since methanation and reverse water gas shift reactions are promoted, leading to low hydrogen yields. Ni (16wt.%)/ZrO2 catalyst is the most selective one, due to its low activity to the secondary reactions that contribute to by-product production. Coke formation is suppressed with the increase of nickel loading up to 16wt.%, and then restarts to increases with the further increase of nickel loading. Polymerization of acetone is the main route for coke deposition over the Ni (≤13wt.%)/ZrO2 catalysts. Methane decomposition and CO disproportion are the two main routes for coke formation over the Ni (≥20wt.%)/ZrO2 catalysts, and methane contributes more to coke formation than CO. In addition, activity of Ni/ZrO2 catalyst towards the secondary reactions such as methanation, reverse water gas shift reaction, methane decomposition, and CO disproportion are closely related to nickel loading and nickel particle sizes.