Electrochemical Performance of Ba0.5Sr0.5Co0.8Fe0.2O3−δ in Symmetric Cells With Sm0.2Ce0.8O1.9 Electrolyte for Nitric Oxide Reduction Reaction

Huangang Shi,Chao Su,Wenyi Tan,Guowei Chu

doi:10.3389/fchem.2019.00947

Abstract

The emission of nitric oxide from the combustion process of fossil fuels causes air pollution problems. In addition to traditional removal methods, nitric oxide can be removed by the electrochemical reduction method. In this study, Ba0.5Sr0.5Co0.8Fe0.2O3−δ powders were synthesized using a solid-state reaction method. Symmetrical cells, with Sm0.2Ce0.8O1.9 as the electrolyte and Ba0.5Sr0.5Co0.8Fe0.2O3−δ as the electrodes, were prepared as the electrochemical reactor for nitric oxide reduction. In the process of electrochemical reduction, nitric oxide reduction occurs at the cathode and oxygen evolution occurs at the anode. To study the nitric oxide reduction performance of the electrode, impedances of the symmetrical cell in different atmospheres were analyzed. For the nitric oxide conversion in symmetric cells, two different modes, dual chamber and single chamber, were applied. Results demonstrated that the denitrification performance of the double chamber was better but the single chamber mode had other advantages in its simple structure. Presliminary stability results of the single chamber symmetric cell show that the electrochemical reduction of nitric oxide in symmetric cells with BSCF performed most reliably.

Highlights

When a fossil fuel burns, it produces pollutants such as sulfur dioxide, carbon dioxide, nitrogen oxides, and particulate matter
The BSCF powders reported in this paper were milled in ethanol for 24 h, with corresponding metal carbonates and oxides as raw materials, to achieve full mixing
It can be seen from the graph that, before calcination, the XRD spectra of the powders show multiple peaks, and there is no fixed crystal structure

Summary

Introduction

When a fossil fuel burns, it produces pollutants such as sulfur dioxide, carbon dioxide, nitrogen oxides, and particulate matter. There are many types of nitrogen oxide and the most important one is nitric oxide (NO) It is abundant in the exhaust gas of thermal power plants, chemical plants, and internal combustion engines. In order to control the emission of NO, selective catalytic reduction (SCR) methods have been used to reduce NO to non-toxic and harmless N2, using NH3 as the reducing agent (Li et al, 2011; Wang et al, 2019b). The reduction reaction of NO occurs at the cathode, Electrochemical Reduction which converts NO into N2 and forms oxygen ions. Driven by the current, reach the anode through the electrolyte and participate in the oxidation reaction by forming oxygen. In the electrochemical denitrification process, the current is equivalent to the reductant. The reactor is a chemical power source, i.e., fuel cell (Huang and Chou, 2010; Wu et al, 2020)

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Results

Conclusion