The Role of Nonmetallic Ion Substitution in Perovskite LaCoO3 for Improved Oxygen Evolution Reaction Activity
The Role of Nonmetallic Ion Substitution in Perovskite LaCoO3 for Improved Oxygen Evolution Reaction Activity
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DOI：
10.1016/j.electacta.2023.143034
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发表时间：
2023-08
影响因子：
6.6
通讯作者：
Maoyu Wang;Kingsley C. Chukwu;Brian A. Muhich;W. Samarakoon;Zizhou He;M. Lucero;Chun-Wai Chang
中科院分区：
文献类型：
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作者：
Maoyu Wang;Kingsley C. Chukwu;Brian A. Muhich;W. Samarakoon;Zizhou He;M. Lucero;Chun-Wai Chang
过渡金属钙钛矿（ABO3）是一种新兴的析氧反应（OER）电催化剂，具有良好的活性和中等的稳定性。尽管人们通过A/B位点的各种元素取代来提高钙钛矿的OER性能，但离子（特别是非金属离子）取代对OER机理的影响却很少研究。越来越多的证据表明，金属中心理论无法解释许多与开放教育资源相关的现象。因此，迫切需要了解钙钛矿中的阳离子和阴离子位点如何决定OER性能。在这里，我们使用 Fe 和 P 共掺杂的 LaCoO3 作为模型体系，通过结合原位/异位 X 射线表征和密度泛函理论 (DFT) 来探索取代对钙钛矿的影响。我们观察到共掺杂材料中 OER 催化活性增强，这归因于更强的过渡金属氧键共价键 (TMOBC)。 O K-edge XAS、电化学性能和DFT的详细分析表明，O 2p和过渡金属3d egorbital之间的杂化可能是钙钛矿OER的更可靠的描述符，它是egorbital理论和TMOBC理论的结合。我们工作中的发现提供了对金属氧化物的 OER 催化机制的见解，这可以指导具有成本效益的氧化物电催化剂的新设计。
Transition metal perovskite (ABO3) is an emerging type of oxygen evolution reaction (OER) electrocatalyst that shows reasonably good activity and moderate stability. Although efforts have been made to improve perovskite’ OER performance by various element substitution at A/B-site, the influence of ion, particularly non-metallic ion, substitutions on the OER mechanism are rarely studied. More and more evidence has shown that the metal-center theory has failed to explain lots of OER-related phenomena. Therefore, it is urgent to understand how the cation and anion sites in perovskite determine OER performance. Here, we used a Fe and P co-doped LaCoO3as a model system to explore the influence of substitution in perovskite by combinngoperando/ex-situX-ray characterization and density functional theroy (DFT). We observed enhanced OER catalytic activities in co-doped materials, which are attributed to the stronger transition-metal-oxygen-bonding-covalency (TMOBC). The detailed analyses by O K-edge XAS, electrochemical performance, and DFT suggest that the hybridization between O 2p and transition metal 3d egorbitals could be a more credible descriptor of perovskite for OER, which is the combination of egorbital theory and TMOBC theory. The finding in our work provides insights into the OER catalysis mechanism on metal oxides, which could guide new design of cost-effective oxide electrocatalysts.