Sulfonated carbon-catalyzed deamination of alanine under hydrothermal conditions

Here, the catalytic effects of sixteen types of solid acid/base additives on the deamination of alanine under hydrothermal conditions at 90–150 °C were examined. As a result, porous sulfonated carbon (FCC-P) showed the highest catalytic activity, which was attributed to the high contents of multiple functional groups like sulfonyl and oxygen functional groups. Using FCC-P as the catalyst, the parameters including the additive amount and alanine solution concentration were optimized to be 0.5 g and ≥ 50 mmol/L, respectively, and the effects of temperature and time were studied detailedly. At 150 °C for 60 min, the deamination yield and alanine conversion achieved to 20.0% and 51.0%, respectively, with the production yield of ammonium at 7.6%. The reusability of two types of sulfonated carbon catalysts was examined. Finally, FCC-P was applied to amino acids including glycine, valine, leucine, and serine, and showed high catalytic activity for each hydrothermal deamination reaction.