Engineering oxygen vacancies in acid-etched MgMn2O4 for efficiently catalytic benzene combustion: Synergistic activation of gaseous oxygen and surface lattice oxygen
Yu Wu, Dongjing Lei, Aijie Wang, Qiuyan Zhang, Hongwei Jian, Haojie Yang, Chong Han
Abstract
The synergistic activation of gaseous oxygen and surface lattice oxygen is essential for designing highly efficient catalysts to eliminate VOCs. Herein, an effective acid treatment was carried out to create more oxygen vacancies by modulating the electronic structure of MgMn 2 O 4 spinels and MgMnO x mixed oxides . The acid-treated MgMn 2 O 4 exhibited outstanding catalytic performance, with the reaction rate of benzene rising by 8.55 times at 200 °C. After acid treatment, MgMn 2 O 4 partially retained its spinel structure, while Mn 2 O 3 in situ grew on the surface due to the selective removal of Mg 2 + . The transformation of Mn–O–Mg into Mn–O weakened the strength of adjacent Mn–O bonds, thereby promoting the release of surface lattice oxygen and the regeneration of oxygen vacancies . In addition, acid-treated MgMn 2 O 4 facilitated the adsorption and activation of gaseous oxygen. In situ DRIFTS analysis proved that the synergistic activation of gaseous oxygen and surface lattice oxygen accelerated the conversion of intermediates, thus contributing to the efficient degradation of benzene.