Mesoporous Beta Zeolite-Supported Ruthenium Nanoparticles for Selective Conversion of Synthesis Gas to C5鈥揅11 Isoparaffins

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• 作者：Kang Cheng ; Jincan Kang ; Shuiwang Huang ; Zhenya You ; Qinghong Zhang ; Jiansheng Ding ; Weiqi Hua ; Yinchuan Lou ; Weiping Deng ; Ye Wang
• 刊名：ACS Catalysis
• 出版年：2012
• 出版时间：March 2, 2012
• 年：2012
• 卷：2
• 期：3
• 页码：441-449
• 全文大小：567K
• 年卷期：v.2,no.3(March 2, 2012)
• ISSN：2155-5435

文摘

Mesoporous beta (meso-beta) zeolites prepared by post-treatment of H-beta with NaOH aqueous solution were studied as supports of Ru catalysts for Fischer鈥揟ropsch (FT) synthesis. The size and volume of the mesopores increased with the concentration of NaOH. The Br酶nsted acidity declined because Na⁺ ions were exchanged into the meso-beta during the post-treatment, and a further ion exchange of the meso-beta with NH₄⁺ followed by calcination, forming H-meso-beta, could recover the Br酶nsted acidity. The use of H-meso-beta or meso-beta instead of H-beta or Na-beta as the support for FT synthesis decreased the selectivities to CH₄ and heavier hydrocarbons (C₁₂⁺) and increased that to C₅鈥揅₁₁ hydrocarbons. The C₅鈥揅₁₁ selectivity depended on the concentration of NaOH used for meso-beta preparation. Under an optimum NaOH concentration, a C₅鈥揅₁₁ selectivity of 77%, significantly higher than the maximum expected from Anderson鈥揝chulz鈥揊lory distribution (45%), was attained with a ratio of isoparaffins to n-paraffins being 2.7. The mesoporosity and the unique acidity of the meso-beta probably contribute to the selective hydrocracking of the primary heavier hydrocarbons formed on Ru nanoparticles into gasoline-range liquid fuels.

Keywords:

mesoporous zeolite; ruthenium nanoparticles; Fischer鈭扵ropsch synthesis; synthesis gas; gasoline; selectivity control