Modification of NAY by LA3+ for the dehydration of lactic acid: The effect of preparation protocol on catalyst microstructure and catalytic performance

Authors

  • Dinghua Yu,

    1. State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 210009, Jiangsu Province, China
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  • Peng Sun,

    1. State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 210009, Jiangsu Province, China
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  • Zhenchen Tang,

    1. State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 210009, Jiangsu Province, China
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  • Zhixian Li,

    1. State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 210009, Jiangsu Province, China
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  • He Huang

    Corresponding author
    1. State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 210009, Jiangsu Province, China
    • State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 210009, Jiangsu Province, China
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Abstract

La-modified NaY zeolites have been prepared through impregnation and in situ synthesis methods. The surface structure of the obtained zeolites was then characterised by XRD, UV–Vis DRS, FT-Far-IR, Raman spectra, H2-TPR, N2 adsorption, and NH3-TPD. The results of the catalytic dehydration reaction of lactic acid showed that the La/NaY catalyst prepared by impregnation method exhibited higher selectivity to acrylic acid than the La–NaY prepared by the in situ synthesis. The characterisation results indicated that the enhanced catalytic performance could be attributed to the difference of La3+ ion location caused by the different preparation protocols, which would influence the electric field distribution of zeolites cages, the reactant adsorption, chemical activation, and the reaction path.

Les zéolithes NaY modifiées avec du lanthane (La) ont été préparées grâce à des méthodes d'imprégnation et de synthèse in situ. La structure de la surface des zéolithes ainsi obtenues a été ensuite caractérisée par DRX, spectrophotomètre UV–VIS DR, FT-Far-IR, spectroscopie Raman, réduction thermo-programmée de H2, adsorption de N2 et désorption thermo-programmée de NH3. Les résultats de la réaction de déshydratation catalytique de l'acide lactique montrent que le catalyseur La/NAY préparé grâce à la méthode d'imprégnation a fait preuve d'une plus grande sélectivité à l'acide acrylique que le catalyseur La/NAY préparé grâce à la synthèse in situ. Les résultats de caractérisation indiquent que le meilleur rendement catalytique peut être dû aux différences d'emplacement de l'ion La3+ causées par les différents protocoles de préparation, qui peuvent influer sur la distribution du champ électrique des cages de zéolithes, l'adsorption du réactif, l'activation chimique et le chemin réactionnel. Can. J. Chem. Eng. © 2010 Canadian Society for Chemical Engineering

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