Fe-doped mesoporous Co3O4@m-SiO2 catalysts for enhanced oxidation of low-concentration methane

Low-concentration methane (LCM) from coal mine ventilation air is difficult to utilize or abate efficiently because of its low calorific value and high global warming potential. Herein, Fe-doped mesoporous Co 3 O 4 @m-SiO 2 catalysts, denoted as FCS-x (x = 0, 1, 2, 4, 7, and 10), are synthesized for LCM oxidation. The results show that Fe doping is associated with crystallite refinement, lattice distortion, and changes in the surface oxygen environment. XPS and H 2 -TPR analyses indicate redistribution of surface oxygen species and enhanced low-temperature reducibility. Methane oxidation activity strongly depends on the nominal Fe doping level, and FCS-10 exhibits the highest activity, with T 50 and T 90 values of 349 and 400 °C, respectively. Moreover, FCS-10 maintains stable catalytic performance during 50 h of continuous operation at 700 °C, and the introduction of 10 vol% H 2 O results in only a slight and mainly reversible decrease in CH 4 conversion.