Abstract
Urea synthesis, currently the largest use of carbon dioxide in organic synthesis, is conventionally operated at high pressure and high temperature. Here, we report for the first time that urea forms at atmosphere and ambient temperatures by negative corona discharge in gas phase. The conversion of CO2 and yields of a solid mixture of urea and ammonium carbamate, which was identified by the 13C NMR spectrum, rise with reducing temperatures and increasing molar ratios of NH3/CO2 and discharge frequencies. The conversion of carbon dioxide was found to be 82.16 % at 20 °C and 1 atm with a molar flow ratio of n(NH3)/n(CO2) of 2.5. High pressure and high temperature as energy inputs are not necessary.
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Acknowledgments
This work was financed by Shaanxi Important Innovative Projects in Science & Technology of China (2009ZKC04-06) & (2010ZDKG-43), the National Key Technology R&D Program of China (2009BAA20B02), the Key Science and Technology Program of Shaanxi Province of China (2010K01-082), Project supported by the National Natural Science Foundation of China (NSFC21006078), and Interdisciplinary funded projects of Northwest University Postgraduates (09YZZ52).
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Xiang, X., Guo, L., Wu, X. et al. Urea formation from carbon dioxide and ammonia at atmospheric pressure. Environ Chem Lett 10, 295–300 (2012). https://doi.org/10.1007/s10311-012-0366-2
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DOI: https://doi.org/10.1007/s10311-012-0366-2