Modification of the surfaces of a gasactivated carbon and a chemically activated carbon with nitric acid, hypochlorite, and ammonia

Development of low-cost biomass-based adsorbents for postcombustion CO2 capture

“…A first series of samples were prepared by activation of the char with 10 cm 3 min -1 of carbon dioxide at different burn-off degrees (20,40 and 50 %). The temperature of activation was set at 800 ºC, based on previous tests in a thermogravimetric analyser.…”

“…It is well known that upon heating in an inert atmosphere, the oxygen surface complexes of carbonaceous materials decompose, releasing CO 2 and CO [32]. CO 2 results from the decomposition of carboxyls, lactones and anhydrides, while CO comes from anhydrides, phenols, carbonyls, quinones and pyrones [20,32,33]. Figure 2 shows the profiles of evolved CO 2 and CO for samples GKOS and GKOSA50, in the course of heating at 15 ºC min -1 in 50 cm 3 min -1 of Ar.…”

“…Attention has also been given to the introduction of nitrogen functionalities into the carbon in order to enhance CO 2 adsorption capacity [7][8][9][10][11][12][13]. Other possibilities include the introduction of nitrogen into the carbon matrix by reaction with gaseous ammonia at high temperatures [14][15][16][17][18][19][20].…”

Removal of copper ions from aqueous solution using silica derived from rice straw: comparison with activated charcoal

“…The importance of the surface chemistry of the studied sorbents should not be ignored. In this work, infrared spectroscopy was used to obtain information about the chemical structure and functional groups of the prepared silica and the commercial activated charcoal (Comez-Serrano et al 1996;Pastor-Villegas et al 1993;Vink et al 1994;Solum et al 1995). The FTIR spectra of silica prepared from rice straw and the activated charcoal are shown in Fig.…”

Ammonia-treated activated carbon as support of Ru-Ba catalyst for ammonia synthesis

“…A number of studies have contributed to understanding the role of the surface chemistry of carbon materials on the final properties of the catalyst, in which emphasis has been mainly concentrated on oxygen surface groups [2]. Carbonnitrogen surface groups have been studied in much less detail and have hardly been exploited for catalyst support applications [3][4][5][6][7][8][9][10]. It is very interesting to study surface nitrogen-containing groups because those groups have a different effect from that of surface oxygen-containing groups.…”