Activated carbon (AC), carbon xerogel (XG), and carbon nanotubes (CNT), with and without N-functionalities, were prepared. Catalysts were obtained after impregnation of these materials with 2 wt.% of iron. The materials were characterized in terms of N 2 adsorption at −196 • C, elemental analysis (EA), and the pH at the point of zero charge (pH PZC ). The p-nitrophenol (PNP) degradation and mineralization (assessed in terms of total organic carbon-TOC-removal) were evaluated during adsorption, catalytic wet peroxidation (CWPO), and Fenton process. The textural and chemical properties of the carbon-based materials play an important role in such processes, as it was found that the support with the highest surface area -AC-presents the best performance in adsorption, whereas the materials with the highest mesopore surface area -XG or Fe/XG-lead to best removals by oxidation processes (for XG it was achieved 39.7 and 35.0% and for Fe/XG 45.4 and 41.7% for PNP and TOC, respectively). The presence of N-functionalities increases such removals. The materials were reused in consecutive cycles: the carbon-based materials were deactivated by hydrogen peroxide, while the catalysts showed high stability and no Fe leaching. For the support with superior performances -XG-, the effect of nitrogen content was also evaluated. The removals increase with the increase of the nitrogen content, the maximum removals (81% and 65% for PNP and TOC, respectively) being reached when iron supported on a carbon xerogel doped with melamine was used as catalyst.The principal disadvantage of the homogeneous Fenton process is the introduction of iron into the treated water, so an additional separation step is required to remove/recover it. An alternative strategy, in order to overcome this drawback, is the immobilization of the catalyst on a porous solid matrix. Distinct materials, like zeolites, pillared clays, silica, silicalites, and carbons have been used to support iron [8][9][10][11][12][13][14].Carbon materials are widely used as supports because they are very flexible materials, since their textural and chemical properties can be easily tailored by physical or chemical treatments [15,16]. Among the carbon materials, activated carbon (AC) is the most reported in the literature as iron support to be used as a catalyst for the Fenton reaction [13,14,[17][18][19][20]. Recently, carbon nanotubes (CNT) [21][22][23] and carbon xerogels (XG) [24] have received intensive attention as iron supports due to their interesting properties when compared with other carbon-based materials, such as mechanical resistance, low limitations to mass transfer, high thermal stability in oxidation conditions, high electronic properties for CNT [25], high purity, mesoporous structure with good pore distribution, and high surface area for XG [26].The presence of nitrogen groups on the surface of carbon-based materials improves their catalytic performance for advanced oxidation processes. This is explained by the increase of the electronic density, and consequently the...