Acta Phys. -Chim. Sin. ›› 2016, Vol. 32 ›› Issue (9): 2327-2336.doi: 10.3866/PKU.WHXB201606225

• ARTICLE • Previous Articles     Next Articles

Comparative Study on Catalytic Performance of the Production of 2, 3-Pentanedione from Lactic Acid Condensation over SiO2-Supported Alkali Metal Nitrates

Liang-Wei SUN,Xin-Li LI*(),Cong-Ming TANG*()   

  • Received:2016-04-12 Published:2016-09-08
  • Contact: Xin-Li LI,Cong-Ming TANG E-mail:lixinlitcm@163.com;tcmtang2001@163.com
  • Supported by:
    the Scientific Research Fund of Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, China(CSPC-2014-3-1);Scientific Research Fund of China West Normal University, China(12B019);Scientific Research Fund of Sichuan Provincial Educational Department, China(16ZA0175)

Abstract:

The production of 2, 3-pentanedione from lactic acid over SiO2-supported alkali metal nitrates under various conditions was investigated. Using nitrate (NO3-) as the anion, the effect of alkali metal cations on Claisen condensation of lactic acid into 2, 3-pentanedione was focused on. Among precursors such as LiNO3, NaNO3, KNO3, and CsNO3, CsNO3 displayed the best catalytic performance. Characterization of the fresh and used catalysts by X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy revealed that all MNO3 (M=Li, Na, K, Cs) salts were transformed into alkali metal lactates during the reaction. Alkali metal lactates were identified as active species for catalytic Claisen condensation of lactic acid into 2, 3-pentanedione. CO2 temperature-programmed desorption (TPD) results of the used catalysts showed that the CsNO3/SiO2 catalyst was the most alkaline. For that reason, the CsNO3/SiO2 catalyst displayed the highest catalytic performance of those examined. The effects of reaction temperature and loading amount of CsNO3 on reaction performance were also discussed. Over the 4.4% (x, molar fraction) CsNO3/SiO2 catalyst, a 54.1% yield of 2, 3-pentanedione was achieved at 300 ℃.

Key words: Lactic acid, 2, 3-Pentanedione, Condensation, Alkali metal nitrate, Lactate

MSC2000: 

  • O643