Promotional effect of acetic acid on simultaneous NO and Hg0 oxidation over LaCoO3 perovskite

Acid etching can effectively alter the mineralization properties of perovskite. In this study, LaCoO3 perovskites were etched via acetic acid (1-3 M) and were used to simultaneously catalyze the oxidation of NO and Hg-0 in coal-fired flue gas. The results demonstrated the ability of the modified acetic acid to improve the low-temperature activity of LaCoO3 perovskite. The acetic acid could erode or dissolve the La-O surface termination and emerge more Co-O surface termination, changing the pore structure, surface morphology, redox capacity, metal oxidation state, and acid-site strength. These changes on the LaCoO3 perovskite allowed for the low-temperature to simultaneously improve the NO and Hg-0 oxidation performances, and the NO reaction temperature was reduced by 25 degrees C. Moreover, when the concentration of acetic acid exceeded 1 M, part of the active Co ions in the perovskite structure were further dissolved, thereby reducing the NO and Hg-0 simultaneous oxidation activity. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

Acid etching of LaCoO3 perovskite can improve its simultaneous oxidation activity towards NO and Hg-0 in coal-fired flue gas, by altering the surface properties and structure of the perovskite.