Influence of the Nanostructure of Gallium Oxide Catalysts on Conversion in the Green Synthesis of Carbamates

• Main Authors: Javishk Shah, Paul Ratnasamy, Maria L. Carreon
• Format: Article
• Language: English
• Published: MDPI AG 2017-12-01
• Series: Catalysts
• Subjects: carbamates; nanostructured gallium oxide; green chemistry
• Online Access: https://www.mdpi.com/2073-4344/7/12/372

The nanostructure of β-gallium oxide crystals influences the conversion to carbamates; specifically, for the synthesis of alkyl carbamates (like propyl N-octylcarbamate) from CO2 and n-propanol in the absence of phosgene. The nanostructures with variable aspect ratios (length (L)/width (D); from 2 to 18) were prepared by the controlled addition of neutral and cationic surfactants during gallium oxide synthesis. These catalysts displayed selectivities to the corresponding carbamates as high as ~70%, superior to non-nanostructured Ga2O3 catalysts. The conversion was found to be inversely proportional to the square of the relative crystallinity. The catalysts retained their structure and catalytic performance upon recycling.