TiO2-based Pd/Fe bimetallic modification for the efficient photothermal catalytic degradation of toluene: The synergistic effect of ∙O2– and ∙OH species

Catalytic Ozonation of Low Concentration Toluene over MnFeOx-USY Catalyst: Effects of Interactions between Catalytic Components and Introduction of Gas Phase NOx

“…The DRIFTS analysis showed the difference of ROS on the catalyst surfaces under the O 3 atmosphere. As shown in Figure e, the characteristic peak around 791 cm –1 was corresponded to ozone ions (*O 3 – ) . The trend of ozone ion (*O 3 – ) adsorption peaks was MnFeO x -USY > MnFeO x > FeO x -USY > MnO x -USY, and no *O 3 – characteristic peaks were observed on USY.…”

“…As shown in Figure 3e, the characteristic peak around 791 cm −1 was corresponded to ozone ions (*O 3 − ). 33 The trend of ozone ion (*O 3 − ) adsorption peaks was MnFeO x -USY > MnFeO x > FeO x -USY > MnO x -USY, and no *O 3 − characteristic peaks were observed on USY. The adsorption peaks of peroxide (*O 2 2− ) appeared in the range of 860−880 cm −1 on MnFeO x -USY, MnFeO x , and FeO x -USY.…”

“…The desorption and migration of adsorbed oxygen species may also determine the activity of ROS. 33 In O 2 -TPD spectra (Figure 3f), three peaks located around below 120, 120−460, and over 460 °C were detected and were attributed to the release of physisorbed oxygen, chemisorbed oxygen species, and lattice oxygen, respectively. 11,34 The oxygen desorption peaks of USY and MnO x -USY were very small, indicating poor mobility and oxygen storage capacity of ROS.…”

Atrazine degradation through a heterogeneous dual-effect process using Fe–TiO2-allophane catalysts under sunlight

“…Moreover, hydroperoxyl radicals are formed through electron transfer from TiO 2 present in the catalyst structure to molecular oxygen, followed by consecutive protonation (Eq. (4) ) [ 32 , 42 , 57 ]. In the heterogeneous dual-effect (HDE) process ( Fig.…”

“…Meanwhile, the solar spectrum typically contains about 4 % UV light; therefore, the sunlight cannot be efficiently used in the photocatalytic process [ 30 ]. To overcome this drawback, studies have shown that the doping of TiO 2 with other narrow bandgap materials, such as iron oxide, could reduce its bandgap and minimize e − /h + recombination rate [ 16 , 21 , 31 , 32 ]. In this way, it is possible to degrade emerging pollutants using photocatalysts containing both iron oxide and TiO 2 through a heterogeneous dual-effect process under sunlight.…”