Adsorption–Reduction Behavior of Co(NH<sub>3</sub>)<span><math xmlns="http://www.w3.org/1998/Math/MathML"><msubsup><mtext> </mtext><mrow><mtext>6</mtext></mrow><mrow><mtext>3+</mtext></mrow></msubsup></math><inlineGraphic></inlineGraphic></span> on Activated Carbon: Fid-Bau Portal

Adsorption–Reduction Behavior of Co(NH₃) $_{6}^{3+}$ on Activated Carbon

Mao, Yan‐Peng / Chen, Yu / Cheng, Jing‐Yi / Zhu, Hai‐Song / Long, Xiang‐Li / Yuan, Wei‐Kang

A novel method has been put forward to retrofit the wet ammonia desulfurization process to realize the combined removal of sulfur dioxide and nitric oxide by introducing soluble cobalt(II) salt into aqueous ammonia solution. The active constituent of scrubbing NO from the flue gases is the ${\rm Co(NH}_{{\rm 3}} {\rm )}_{{\rm 6}}^{{\rm 2 + }} $ produced by ammonia coordinating with Co²⁺. The regeneration of ${\rm Co(NH}_{{\rm 3}} {\rm )}_{{\rm 6}}^{{\rm 2 + }} $ can be realized under the catalysis of activated carbon so as to sustain a high NO removal efficiency for a long time. In this paper, the adsorption–reduction behavior of ${\rm Co(NH}_{{\rm 3}} {\rm )}_{{\rm 6}}^{{\rm 3 + }} $ on activated carbon has been researched using scanning electron microscopy, X‐ray diffraction, and X‐ray photoelectron spectroscopy. A conclusion can be drawn from the results that cobalt ions in the aqueous solution are adsorbed by activated carbon and most of them are reduced to Co²⁺ ions, and some of the Co²⁺ ions are further reduced into metallic cobalt. The results also demonstrate that the functional groups on the surface of carbon take part in this redox reaction. The CH groups on the carbon surface are oxidized into COH, and then some of the hydroxyl groups are further oxidized into carbonyl or carboxyl groups.