Synthesis of self-renewing Fe(0)-dispersed ordered mesoporous carbon for electrocatalytic reduction of nitrates to nitrogen

Xiaoning Liu; Yicong Wang; Richard L Smith Jr; Le Liu; Xinhua Qi

doi:10.1016/j.scitotenv.2022.155640

Synthesis of self-renewing Fe(0)-dispersed ordered mesoporous carbon for electrocatalytic reduction of nitrates to nitrogen

Sci Total Environ. 2022 Aug 25:836:155640. doi: 10.1016/j.scitotenv.2022.155640. Epub 2022 May 2.

Authors

Xiaoning Liu¹, Yicong Wang¹, Richard L Smith Jr², Le Liu³, Xinhua Qi⁴

Affiliations

¹ College of Environmental Science and Engineering, Nankai University, No. 38, Tongyan Road, Jinnan District, Tianjin 300350, China.
² Graduate School of Environmental Studies, Tohoku University, Aramaki Aza Aoba 6-6-11, Aoba-ku, Sendai 980-8579, Japan.
³ College of Environmental Science and Engineering, Nankai University, No. 38, Tongyan Road, Jinnan District, Tianjin 300350, China; National-Local Joint Engineering Research Center of Biomass Resource Utilization, Nankai University, No. 38, Tongyan Road, Jinnan District, Tianjin 300350, China.
⁴ College of Environmental Science and Engineering, Nankai University, No. 38, Tongyan Road, Jinnan District, Tianjin 300350, China; National-Local Joint Engineering Research Center of Biomass Resource Utilization, Nankai University, No. 38, Tongyan Road, Jinnan District, Tianjin 300350, China. Electronic address: qixinhua@nankai.edu.cn.

PMID: 35513147
DOI: 10.1016/j.scitotenv.2022.155640

Abstract

In electrocatalytic reduction of nitrates to nitrogen, key issues are electrode activity, sustainable materials, preparation methods and cost. Herein, lignin, Fe³⁺ ion, and non-ionic surfactant were combined with evaporation-induced self-assembly (EISA) to prepare zero-valent Fe-dispersed ordered mesoporous carbon (OMC) electrode materials denoted as Fe#OMC. The method developed for preparing Fe-coordinated OMC material avoids the use of toxic phenols, aldehyde reagents and metal doping compounds. When synthesized Fe#OMC samples were applied as electrode materials for the electrocatalytic reduction of nitrate in aqueous solutions, maximum nitrate nitrogen removal was as high as 5373 mg N·g^-1 Fe from aqueous solutions containing 400 mg·L^-1 NO₃^--N, while nitrogen selectivity was close to 100%, exceeding catalytic performance of comparable materials. Active hydrogen produced by electrolysis of water during the reaction re-reduced Fe ions formed in the OMC material and stabilized Fe#OMC electrode performance and recycle. The Fe#OMC electrode is self-renewing with respect to its Fe zero-valent state, is simple to prepare from sustainable materials and is effective for electrocatalytic reduction of nitrate or nitrogen-containing compounds in water.

Keywords: Electrocatalysis; Lignin; Meso-porous material; Nitrate reduction; Water treatment.

MeSH terms

Carbon*
Catalysis
Nitrates*
Nitrogen
Nitrogen Oxides
Water

Substances

Nitrates
Nitrogen Oxides
Water
Carbon
Nitrogen