Mass and surface changes of activated carbon treated with nitric acid. Thermal behavior of the samples

A review on surface modification of activated carbon for carbon dioxide adsorption

“…Liquid phase oxidations can introduce a higher amount of oxygen into the carbon surface at much lower temperatures compared to the gas phase treatment [65]. Nitric acid or nitric and sulfuric acid mixture have been shown to be very effective oxidizing agents due to introduction of a significant number of oxygenated acidic functionalities onto the carbon surface that mainly include carboxylic, lactone, and phenolic hydroxyl groups [49,52,[67][68][69][70][71]. It has been demonstrated that oxidation of activated carbon in the gas phase increases mainly the concentration of hydroxyl and carbonyl surface groups while oxidation in liquid phase can incorporate a higher amount of oxygen in the form of carboxylic and phenolic hydroxyl groups onto the carbon surface at much lower temperatures compared to the gas phase oxidation [65,67].…”

Selective Oxidation of Glycerol Catalyzed by Rh/Activated Carbon: Importance of Support Surface Chemistry

“…The slight decrease in AC 1 surface area may be due to the abundant presence of oxygen-containing groups introduced on the surface of the activated carbon by treatment with HNO 3 , which possibly block the entry of N 2 inside the small pores. After treatment at 900°C (sample AC 1tt900 ), the mentioned functional groups were removed by thermal decomposition and the area of the corresponding support increased slightly comparatively to the original carbon [24,25]. The textural parameters of the Pd/AC 0 catalyst decreased only slightly compared to the unloaded carbon.…”

Removal of organic sulfur compounds from diesel by adsorption on carbon materials

“…Liquid phase oxidations can introduce a higher amount of oxygen into the carbon surface at much lower temperatures compared to the gas phase treatment (Mangun et al 1999). Nitric acid or nitric and sulfuric acid mixtures have been shown to be very effective oxidizing agents due to the introduction of a significant number of oxygenated acidic functionalities onto the carbon surfaces that include mainly carboxylic, lactone, and phenolic hydroxyl groups (Noh and Schwarz 1990, Otake and Jenkins 1993, Gomez-Serrano et al 1997, Figueiredo et al 1999, Li et al 2002, Miyazaki et al 2004. Table 3 lists the adsorption capacity of sulfur compounds on ACs with different oxidation methods.…”