Interactions of NO 2 and NO with carbonaceous adsorbents containing silver nanoparticles

Authors:

• Mykola Seredych,
• Svetlana Bashkova,
• Robert Andrzej Pietrzak,
• Teresa J. Bandosz

Abstract

Interactions of NO ₂ and NO (the product of NO ₂ reduction by carbon) with biomass-based carbonaceous materials with silver nanoparticles deposited on the surface were studied. The surface of the materials was characterized using adsorption of nitrogen, X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and thermogravimetric analysis (TGA). The results showed that the amount of NO ₂ adsorbed, its conversion to NO, and the amount ofNOreleased from the carbon surface depend on the carbon's content of silver. More silver results in a better performance of the adsorbent. The products of NO ₂ interactions with silver include surface chelates such as Ag ₂-O-NOor Ag-O ₂-NO. Another element, active in the surface reactions with NO ₂, is phosphorus. Both silver and phosphorus species are oxidized by NO ₂. The product of NO ₂ reduction, NO, is either retained on the carbon surface by its interactions with metallic silver or is further reduced to N ₂Oor N ₂. Besides silver, carbon support is also active in the reduction of NO ₂ to NO. Carbon monoxide formed in such a processes can reduce silver oxide nanoparticles, and thus, it provides more metallic silver for interactions with NO. © 2010 American Chemical Society.