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Title: Elucidating the Role of B-Site Cations toward CO 2 Reduction in Perovskite-Based Solid Oxide Electrolysis Cells
Solid oxide electrolysis cells (SOECs) are promising for the selective electrochemical conversion of CO 2 , or mixed streams of CO 2 and H 2 O, into high energy products such as CO and H 2 . However, these systems are limited by the poor redox stability of the state-of-the-art Ni-based cathode electrocatalysts. Due to their favorable redox properties, mixed ionic-electronic conducting (MIEC) oxides have been considered as promising alternatives. However, improvement of the electrochemical performance of MIEC-based SOEC electrocatalysts is needed and requires an understanding of the factors that govern their activity. Herein, we investigate the effect of B-site 3 d metal cations (Cr, Fe, Co, Ni) of LaBO 3 perovskites on their CO 2 electrochemical reduction activity in SOECs. We find that their electrochemical performance is highly dependent on the nature of the B-site cation and trends as LaFeO 3 > LaCoO 3 > LaNiO 3 > LaCrO 3 . Among these perovskites, LaNiO 3 is the least stable and decomposes under electrochemical conditions. In situ characterization and ab initio theoretical calculations suggest that both the nature of the B-site cation and the presence of oxygen surface vacancies impact the energetics of CO 2 adsorption and reduction. These studies provide fundamental insights critical toward devising ways to improve the performance of MIEC-based SOEC cathodes for CO 2 electroreduction.  more » « less
Award ID(s):
1929306 2333166
PAR ID:
10331281
Author(s) / Creator(s):
; ; ; ; ; ; ;
Date Published:
Journal Name:
Journal of The Electrochemical Society
Volume:
169
Issue:
3
ISSN:
0013-4651
Page Range / eLocation ID:
034532
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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