The effect of the gradual thermal decomposition of surface oxygen species on the chemical and catalytic properties of oxidized activated carbon

Thermogravimetric and spectroscopic study (TG–DTA/FT–IR) of activated carbon from the renewable biomass source Babassu

“…above 400 °C (third step), since the oxidizing atmosphere used is different from that one used by these authors. 23,24 In addition, it can be observed that the activated carbon samples have similar decomposition profiles in the TGA curves with intense exothermic peaks (DTA) related to the thermal decomposition of matter organic, so that the last mass loss steps, which occur overlapped, can also be related to the carbon skeleton of the ACs, leading to ash with average percentage of 7.4%. The data related to qualitative analysis by EDX for identification of the main metal elements in form of its oxides are shown in Table 1.…”

“…The gaseous products carbon monoxide (CO) and carbon dioxide (CO 2 ) identified in the FT-IR spectra during the thermal decomposition (TG-DTA) of the ACs samples in N 2 atmosphere for determinate temperature ranges observed in GS curve are due to surface groups. 23 For the range 30 -100 °C, the FT-IR spectrum (a) shows bands located at around 3700 and 1500 cm -1 corresponding to adsorbed water, while between the ranges of 170 -400 and 530 -580 °C the spectrum (b) shows CO 2 as a thermal decomposition product of the carboxylic and lactonic groups respectively. 24 For the ranges of 400 -530 and 580 -600 °C, the FT-IR spectrum (c) shows CO as the main product released.…”

“…Furthermore, it is possible that the irregular rings observed especially in Figure 5 (AC3, AC4) evidence the cell walls of parenchyma and collenchyma tissues, common structures in young parts of plants, such as palm petioles. 25 The pores represented by dark spots in the images, Figure 5, were formed through an aggressive heating process (burn-off), 1,23 which along with the activating agent resulted in an apparent carbonaceous matrix with high porosity.…”

Surface characteristics and antibacterial activity of a silver-doped carbon monolith

“…According to the literature [21,[23][24][25], TPD peaks can be assigned to specific surface groups. The CO 2 profile results from carboxylic acids at low temperatures and lactones at higher temperatures; carboxylic anhydrides are the origin of both CO and CO 2 peaks; phenols, ethers and carbonyls are the origin of the CO peak.…”

Impacts of Biochar (Black Carbon) Additions on the Sorption and Efficacy of Herbicides

“…Preparation of activated charcoal involves two steps: 1) the carbonization of the raw material (typically at temperatures below 800 ºC) in an inert atmosphere, followed by 2) the activation by chemical or thermal methods of the carbonized product (Hassler, 1974;Yalcin & Sevinc, 2000). Chemical treatments both provide an opportunity to unify the surface behavior as well as to customize the overall surface area and porosity of the activated char (Hassler, 1974;Szymanski et al, 2002;Marsh & Rodríguez-Reinoso, 2006). In summary, biochar properties are attributed to its characteristics, which depend on the pyrolysis conditions, temperature and time, as well as the feedstock used.…”