Spectroscopic investigations of sequential nitric acid treatments on granulated activated carbon: Effects of surface oxygen groups on π density

Biologically derived melanin electrodes in aqueous sodium-ion energy storage devices

“…NatMel, SynMel, and E-SynMel exhibit Brunauer-Emmett-Teller (BET) surface areas of 19.9, 10.7, and 9.2 m 2 g −1 , respectively. The surface areas of all melanins in this study are smaller than many other carbon-based electrode materials (35,55,56). SynMel and E-SynMel exhibit hysteresis in N 2 adsorption-desorption isotherms, which suggests that these materials have a mesoscale disorder (57).…”

Roles of surface chemistry and structural defects of activated carbons in the oxidative desulfurization of benzothiophenes

“…1) are featureless. Taking the analysis a step further, the band at 1700-1740 cm À1 is assigned to the stretching vibration of C@O bond in (ACOOH) in carboxylic acids or in esters/aldehydes [57,68]. When C@O bonds in anhydride and lactone were conjugated with other double bonds and/or aromatic rings, their stretching bands are expected to appear at higher wave numbers [69].…”

“…Furthermore, although the surface chemistry of carbons has been shown important for thiophenic compound adsorption [31][32][33]36,50,57] and (separately) catalysis [31,[58][59][60], the specific role of activated carbon in promoting the oxidation reaction is not yet clear. As a result, relationships between carbon characteristics and performance are unknown, making process optimization a trial-and-error process.…”

Catalyst deactivation pattern along a residue hydrotreating bench-scale reactor

“…3b shows the subtraction of the spectra of the Z i -spent and the fresh sample spectra taken at 300 • C. In this region the absorption is expected due to stretching of C O (1750-1650 cm −1 ), aromatic C C (1630-1500 cm −1 ) and the "coke peak" (1585 cm −1 ) [30]. As the catalyst is under an oxidation process, the three peaks detected at 1782, 1622, and 1554 cm −1 can be attributed to graphite oxide [34][35][36]. These peaks are related to the amount of the refractory carbonaceous compounds (hard coke).…”