Fe₃C@C/C for catalytic ozonation of silicon-containing wastewater: Dual improvement of silicon resistance and catalytic effect

The improvement of catalysts' stability under harsh reaction conditions is vital for their practical applicability. Herein, iron carbide (Fe3C) nanoparticles were encapsulated in graphitic carbon in situ and a carbon ball served as the carrier. The synthesized Fe3C@C/C was first utilized to treat an m-cresol wastewater containing Si via catalytic ozonation. Compared with the commercial Fe/Al3O3 catalyst, the resistance to Si of the Fe3C@C/C was improved 22.68 times, while the TOC removal rate increased by a factor of 2.9, and it remained stable during 10 cycles and 120 0 0 min of continuous reaction, which further demonstrated its potential for diverse applications. The catalyst exhibits improved resistance to Si because of the dual protection from the carbon-encapsulated structure and carbon carrier. Density functional theory calculations show that the encapsulation of Fe3C using carbon significantly increases the resistance to adsorption of Si on its active sites. In addition, the activation of O-3 is unimpeded on the Fe3C adsorption sites by the protection from C, thus the generation of reactive oxygen species (ROS) by ozone is largely promoted. The mechanism associated with the resistance of the Fe3C@C/C catalyst to Si and its elevated activity are also elucidated. (c) 2022 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.