Highly Efficient CO2 Electrolysis on Cathodes with Exsolved Alkaline Earth Oxide Nanostructures

Lingting Ye; Changchang Pan; Minyi Zhang; Chunsen Li; Fanglin Chen; Lizhen Gan; Kui Xie

doi:10.1021/acsami.7b07039

Highly Efficient CO₂ Electrolysis on Cathodes with Exsolved Alkaline Earth Oxide Nanostructures

ACS Appl Mater Interfaces. 2017 Aug 2;9(30):25350-25357. doi: 10.1021/acsami.7b07039. Epub 2017 Jul 19.

Authors

Lingting Ye¹, Changchang Pan¹, Minyi Zhang², Chunsen Li², Fanglin Chen³, Lizhen Gan^{1

4}, Kui Xie¹

Affiliations

¹ Key Lab of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences , Fuzhou, Fujian 350002, China.
² State Key Lab of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences , Fuzhou, Fujian 350002, China.
³ Department of Mechanical Engineering, University of South Carolina , 300 Main Street, Columbia, South Carolina 29208, United States.
⁴ School of Transportation and Civil Engineering, Fujian Agriculture and Forestry University , 15 Shangxiadian Road, Fuzhou, Fujian 350002, China.

PMID: 28686008
DOI: 10.1021/acsami.7b07039

Abstract

The solid oxide CO₂ electrolyzer has the potential to provide storage solutions for intermittent renewable energy sources as well as to reduce greenhouse gas emissions. One of the key challenges remains the poor adsorption and activity toward CO₂ reduction on the electrolyzer cathode at typical operating conditions. Here, we show a novel approach in tailoring a perovskite titanate (La, Sr)TiO_3+δ cathode surface, by the in situ growing of SrO nanoislands from the host material through the control of perovskite nonstoichiometry. These nanoislands provide very enhanced CO₂ adsorption and activation, with stability up to 800 °C, which is shown to be in an intermediate form between carbonate ions and molecular CO₂. The activation of adsorbed CO₂ molecules results from the interaction of exsolved SrO nanoislands and the defected titanate surface as revealed by DFT calculations. These cathode surface modifications result in an exceptionally high direct CO₂ electrolysis performance with current efficiencies near 100%.

Keywords: alkaline earth oxide; carbon dioxide; electrolysis; perovskite; solid oxide electrolyzer.