Theoretical study on NO x adsorption properties over the α-MnO2(110) surface

Xingguang Hao; Xin Song; Kai Li; Chi Wang; Kunlin Li; Yuan Li; Xin Sun; Ping Ning

doi:10.1039/c9ra09455e

Theoretical study on NO _x adsorption properties over the α-MnO₂(110) surface

RSC Adv. 2020 Mar 5;10(16):9539-9548. doi: 10.1039/c9ra09455e. eCollection 2020 Mar 2.

Authors

Xingguang Hao¹, Xin Song¹, Kai Li¹, Chi Wang², Kunlin Li¹, Yuan Li¹, Xin Sun¹, Ping Ning^{1

3}

Affiliations

¹ Faculty of Environmental Science and Engineering, Kunming University of Science and Technology Kunming 650500 PR China sunxin_kmust@163.com ningpingkmust@163.com +86-871-65920507 +86-871-65920507.
² Faculty of Chemical Engineering, Kunming University of Science and Technology Kunming 650500 PR China.
³ National-Regional Engineering Center for Recovery of Waste Gases from Metallurgical and Chemical Industries, Kunming University of Science and Technology Kunming 650500 PR China.

Abstract

Herein, α-MnO₂ was studied as an adsorbent for the removal of NO _x (NO, NO₂) derived from flue gas. First-principles calculations based on the density functional theory (DFT) were performed to investigate the NO _x adsorption properties over the α-MnO₂(110) surface. NO strongly adsorbed over the α-MnO₂(110) surface via chemisorption spontaneously under 550 K. The NO₂ molecules adsorbed over the surface via chemisorption and physisorption when the terminal N- and O atoms approached the surface, respectively. The joint adsorption of NO _x was more stable than the isolated adsorption system. Furthermore, the net charge was transferred from the molecule to the surface. The surface and temperature affected the entropy, enthalpy, NO adsorption and NO₂ desorption in the temperature range of 300-550 K. The equilibrium constants decreased with an increase in temperature, which reduced the conversion rate.