Efficient Synthesis of Amides Over Cu-Fe Decorated Multiwalled Carbon Nanotubes and Mesoporous Carbon Catalysts.

Abstract

A mixture of Cu (10%) and Fe (1 to 9%) was deposited on multiwalled carbon nanotubes (MWCNTs) and mesoporous carbon (MC). The catalytic activity was investigated in a reaction between carboxylic acids/esters and aromatic amines. The physico-chemical properties of the materials were characterized by different analytical techniques such as powder XRD (X-ray diffraction), BET (brunauer emmett teller) surface area, XPS (X-ray photoelectron spectroscopy), TPD-NH₃ (thermal desorption spectroscopy), SEM-EDS (scanning electron microscopy-energy dispersive spectroscopy) and TEM (transmission electron microscopy). The catalytic activity was investigated in the synthesis of aliphatic and aromatic amides from aliphatic/aromatic carboxylic acids and esters with aniline/benzyl amine. The yields of the product/s were in the range 30 to 92% with 100% selectivity. The percentage yield of amides from esters was found to be less than that of corresponding acids. Cu along with 5% of Fe supported on MWCNTs was found to be a better catalyst than when supported on MC, with respect to the isolated yield of the product/s and recyclability. The catalytic activity of the materials had a good correlation with their surface acidity. A plausible reaction mechanism has been proposed.