Adsorption of acetaldehyde onto carbide-derived carbon modified by oxidation

The adsorption of acetaldehyde over carbide-derived carbon (CDC) modified with nitric acid, hydrogen peroxide, or air was investigated. The physicochemical properties of the original and modified CDCs were characterized by N2 adsorption, Fourier transform infrared spectrometer, temperature programmed desorption and X-ray photoelectron spectroscopy. It was observed that the oxidation modification, especially the nitric acid treatment, could significantly enhance the adsorption performance of CDC for acetaldehyde. The increase of acidic oxygen-containing groups like carboxylic acids and anhydrides in the modified CDCs results in the increase of adsorption performance. The density functional theory calculations and in situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy show that these acidic oxygen-containing groups display strong hydrogen bonding interactions with acetaldehyde molecule, leading to the enhanced adsorption performance.