Catalytic Upgrading of Biomass-Derived Compounds via C鈥揅 Coupling Reactions: Computational and Experimental Studies of Acetaldehyde and Furan Reactions in HZSM-5

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• 作者：Cong Liu ; Tabitha J. Evans ; Lei Cheng ; Mark R. Nimlos ; Calvin Mukarakate ; David J. Robichaud ; Rajeev S. Assary ; Larry A. Curtiss
• 刊名：Journal of Physical Chemistry C
• 出版年：2015
• 出版时间：October 22, 2015
• 年：2015
• 卷：119
• 期：42
• 页码：24025-24035
• 全文大小：622K
• ISSN：1932-7455

文摘

Catalytic C鈥揅 coupling and deoxygenation reactions are essential for upgrading of biomass-derived oxygenates to fuel-range hydrocarbons. Detailed understanding of mechanistic and energetic aspects of these reactions is crucial to enabling and improving the catalytic upgrading of small oxygenates to useful chemicals and fuels. Using periodic density functional theory (DFT) calculations, we have investigated the reactions of furan and acetaldehyde in an HZSM-5 zeolite catalyst, a representative system associated with the catalytic upgrading of pyrolysis vapors. Comprehensive energy profiles were computed for self-reactions (i.e., acetaldehyde coupling and furan coupling) and cross-reactions (i.e., acetaldehyde + furan) of this representative mixture. Major products proposed from the computations are further confirmed using temperature controlled mass spectra measurements. The computational results show that furan interacts with acetaldehyde in HZSM-5 via an alkylation mechanism, which is more favorable than the self-reactions, indicating that mixing furans with aldehydes could be a promising approach to maximize effective C鈥揅 coupling and dehydration while reducing the catalyst deactivation (e.g., coke formation) from aldehyde condensation.