Interaction between SO2 and NO in their adsorption and photocatalytic conversion on TiO2

Haiming Wang; Hanzi Liu; Zhen Chen; Andrei Veksha; Grzegorz Lisak; Changfu You

doi:10.1016/j.chemosphere.2020.126136

Interaction between SO₂ and NO in their adsorption and photocatalytic conversion on TiO₂

Chemosphere. 2020 Jun:249:126136. doi: 10.1016/j.chemosphere.2020.126136. Epub 2020 Feb 6.

Authors

Haiming Wang¹, Hanzi Liu², Zhen Chen², Andrei Veksha³, Grzegorz Lisak⁴, Changfu You⁵

Affiliations

¹ Key Laboratory for Thermal Science and Power Engineering of the Ministry of Education, Department of Energy and Power Engineering, Tsinghua University, Beijing, 100084, China; Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore, 637141, Singapore. Electronic address: wanghaiming89@gmail.com.
² Key Laboratory for Thermal Science and Power Engineering of the Ministry of Education, Department of Energy and Power Engineering, Tsinghua University, Beijing, 100084, China.
³ Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore, 637141, Singapore.
⁴ Residues and Resource Reclamation Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore, 637141, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, Singapore, 639798, Singapore.
⁵ Key Laboratory for Thermal Science and Power Engineering of the Ministry of Education, Department of Energy and Power Engineering, Tsinghua University, Beijing, 100084, China. Electronic address: youcf@tsinghua.edu.cn.

PMID: 32044609
DOI: 10.1016/j.chemosphere.2020.126136

Abstract

The simultaneous adsorption and photocatalytic conversion of SO₂ and NO on P25-TiO₂ were studied. In particular, the interaction of SO₂ and NO on each other's adsorption and photocatalytic oxidation was discussed. The adsorption of NO on P25 was negligible when comparing to that of SO₂, while with the coexistence of NO and SO₂ in flue gas, both the adsorption of SO₂ and NO were improved. In the presence of water and oxygen, the photocatalytic oxidation efficiency of NO with an efficiency of >69% was observed on irradiated TiO₂ surface, which lasted for at least 1000 min. Oxygen was found to have much more important effect than water on the photocatalytic oxidation of NO. In the presence of SO₂ however, the photocatalytic process of NO was largely reshaped. The whole process was controlled by the photocatalytic oxidation of SO₂. A dramatic efficiency decease (breakthrough of the catalyst bed) was observed for both NO and SO₂ due to the catalyst deactivation caused by the poisoning of SO₂ oxidation products. Before the breakthrough, the photocatalytic conversion efficiency of NO increased with increasing the SO₂ concentration, which was mainly due to the improved NO adsorption in the presence of SO₂.

Keywords: Adsorption; Interaction; NO; Photocatalytic conversion; SO(2).

MeSH terms

Adsorption
Air Pollutants
Catalysis
Nitrogen Oxides / chemistry*
Oxidation-Reduction
Oxygen
Photochemical Processes
Sulfur Dioxide / chemistry*
Titanium / chemistry*
Water

Substances

Air Pollutants
Nitrogen Oxides
Water
Sulfur Dioxide
titanium dioxide
Titanium
Oxygen