Abstract Alkali-treated zeolite material was prepared by using 0.1–0.4 mol/L NaOH aqueous solution, as characterized by XRD, SEM, N2 adsorption-desorption technique and ammonia-temperature programmed desorption (NH3-TPD). The as-prepared zeolite was found… Click to show full abstract
Abstract Alkali-treated zeolite material was prepared by using 0.1–0.4 mol/L NaOH aqueous solution, as characterized by XRD, SEM, N2 adsorption-desorption technique and ammonia-temperature programmed desorption (NH3-TPD). The as-prepared zeolite was found to be an effective catalyst for alcoholysis of urea and disubstituted urea to produce alkyl carbamate, getting 91.8–100% conversion of urea and substituted urea with >98.0% selectivity to alkyl carbamates. The results indicated that the high reactivity of the zeolites for alcoholysis of urea and N-substituted urea could be mainly ascribed to the enhanced specific area and balance between acidic and basic sites on the HZSM-5 surface caused by the alkali-treatment. This catalyst can be easily recovered and reused.
               
Click one of the above tabs to view related content.