Oxygen-deficient WO3-x spheres for electrochemical N2 oxidation to nitrate

Ying Zhang; Tongxin Xu; Yabing Shang; Guoxin Zhang; Zi-Feng Yan

doi:10.1016/j.jcis.2023.07.031

Oxygen-deficient WO_3-x spheres for electrochemical N₂ oxidation to nitrate

J Colloid Interface Sci. 2023 Nov 15;650(Pt A):669-675. doi: 10.1016/j.jcis.2023.07.031. Epub 2023 Jul 7.

Authors

Ying Zhang¹, Tongxin Xu¹, Yabing Shang¹, Guoxin Zhang², Zi-Feng Yan¹

Affiliations

¹ Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao, Shandong 266580, China.
² College of Energy Storage Technology, Shandong University of Science and Technology, Qingdao, Shandong 266590, China. Electronic address: zhanggx@sdust.edu.cn.

PMID: 37437446
DOI: 10.1016/j.jcis.2023.07.031

Abstract

Nitrate synthesis via the electrochemical nitrogen oxidation reaction (e-NOR) is widely recognized as a potential alternative to the energy-intensive Ostwald process. However, electrocatalysts with strong N₂ adsorption and activation abilities remain largely undeveloped due to kinetic hindrances caused by the high bond energy of NN. Here we designed a hollow WO₃ sphere with an optimal concentration of oxygen vacancies and studied its e-NOR performance. The optimally synthesized oxygen-deficient WO₃ (WO_3-x) achieved a high nitrate yield of 311.15 µmol h^-1g_cat.^-1 and a Faraday efficiency of 2.00 %, which is probably due to the presence of a moderate amount of oxygen vacancies on the WO_3-x surface and the hollow spherical structure, which further improves the accessibility of the inner active surface. Our work could potentially stimulate research into transition metal oxide-based materials for e-NOR applications.

Keywords: Electrocatalytic nitrogen oxidation; Nitrate; Oxygen vacancy; Tungsten oxide.