Exploring the mechanism of ZrO2 structure features on H2O2 activation in Zr–Fe bimetallic catalyst

Abstract Bimetallic Fenton catalyst has attracted widespread attention in refractory organics removal. Herein, we firstly investigated the influence of ZrO2 structure features on H2O2 activation in Zr-Fe bimetallic catalyst. The results show that the heterojunction structure will be formed after high temperature calcination, which makes the ability of Zr-Fe bimetallic catalyst to activate H2O2 for bisphenol A degradation is 3.1 times higher than that of α-Fe2O3 without Zr doping. Through characterization and density functional theory, it was identified that compared to (1 1 0) interface, the adsorption energy of H2O2 on iron sites at (1 1 0)-(1 0 0) interface reduced by 1.27 kJ mol−1, while the Fe–O bond length in the stable configuration of Fe-OOH increased by 0.16 A, which was beneficial to the association and dissociation of H2O2 on iron sites. Besides, the surface -OH of amorphous ZrO2 in Zr-Fe bimetallic catalyst synthesized under low temperature conditions could promote HO2•/O2•- formation through the surface electron transfer, accelerating the Fe(III) reduction. In conclusion, this study reveals the influence of environment-friendly ZrO2 structure features on H2O2 activation, proposes a new insight into strengthening the synergistic effect between bimetals, and provides a reference for the structural optimization of bimetallic catalysts.