RT Journal Article
T1 Lignin-based activated carbons as metal-free catalysts for the oxidative degradation of 4-nitrophenol in aqueous solution
A1 Martín Martinez, María
A1 Martín Martínez, María
A1 Barreiro, Maria Filomena F.
A1 Silva, Adrián M. T.
A1 Figueiredo, José L.
A1 Faria, Joaquim L.
A1 Gomes, Helder T.
AB A wheat and hemp lignin, obtained from a soda pulping-precipitation process, was carbonized at 800 ◦C under N2 atmosphere. The resulting carbon material was thermally activated under oxidative atmosphere at four different temperatures (150, 200, 300 and 350 ◦C). The materials prepared at higher activation temperatures (300 and 350 ◦C) have proven their potential in the elimination of 4-nitrophenol (4-NP) from aqueous model solutions (5 g L−1) when using catalytic wet peroxide oxidation (CWPO). In these conditions we were able to remove around 70% of 4-NP after 24 h, with an efficient H2O2 decomposition, in experiments conducted at relatively mild operating conditions (atmospheric pressure, 50 ◦C, pH = 3, catalyst load = 2.5 g L−1 and [H2O2]0 = 17.8 g L−1). By increasing the working temperature to 80 ◦C, complete 4-NP removal was obtained within 48 h (against 93% 4-NP removal at 50 ◦C), with an efficiency of H2O2 consumption of 70% and a significant mineralization (61%). On the other hand, the materials prepared at lower activation temperatures (150 and 200 ◦C), with higher basicity, promote the faster but inefficient H2O2 decomposition, 4-NP removal being lower than 25% after 24 h at 50 ◦C in CWPO. This can be attributed to the formation of species other than HO• radicals during H2O2 decomposition, the recombination of the formed radicals into non-reactive species and a poor adsorption capacity.
PB Elsevier
SN 0926-3373
YR 2017
FD 2017-12
LK https://hdl.handle.net/20.500.14352/107220
UL https://hdl.handle.net/20.500.14352/107220
LA eng
NO Maria Martin-Martinez, Maria Filomena F. Barreiro, Adrián M.T. Silva, José L. Figueiredo, Joaquim L. Faria, Helder T. Gomes, Lignin-based activated carbons as metal-free catalysts for the oxidative degradation of 4-nitrophenol in aqueous solution, Applied Catalysis B: Environmental, Volume 219, 2017, Pages 372-378, ISSN 0926-3373, https://doi.org/10.1016/j.apcatb.2017.07.065.
DS Docta Complutense
RD 9 abr 2025