Identifying the Key Role of Pyridinic‐N–Co Bonding in Synergistic Electrocatalysis for Reversible ORR/OER,Advanced Materials

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Identifying the Key Role of Pyridinic‐N–Co Bonding in Synergistic Electrocatalysis for Reversible ORR/OER
Advanced Materials ( IF 27.4 ) Pub Date : 2018-04-20 , DOI: 10.1002/adma.201800005
Xue-Rui Wang ₁ , Jie-Yu Liu ₂ , Zi-Wei Liu ₁ , Wei-Chao Wang ₂ , Jun Luo ₃ , Xiao-Peng Han ₄ , Xi-Wen Du ₁ , Shi-Zhang Qiao _{1,

5} , Jing Yang ₁

Affiliation

For many regenerative electrochemical energy‐conversion systems, hybrid electrocatalysts comprising transition metal (TM) oxides and heteroatom‐doped (e.g., nitrogen‐doped) carbonaceous materials are promising bifunctional oxygen reduction reaction/oxygen evolution reaction electrocatalysts, whose enhanced electrocatalytic activities are attributed to the synergistic effect originated from the TM–N–C active sites. However, it is still ambiguous which configuration of nitrogen dopants, either pyridinic or pyrrolic N, when bonded to the TM in oxides, predominately contributes to the synergistic effect. Herein, an innovative strategy based on laser irradiation is described to controllably tune the relative concentrations of pyridinic and pyrrolic nitrogen dopants in the hybrid catalyst, i.e., NiCo₂O₄ NPs/N‐doped mesoporous graphene. Comparative studies reveal the dominant role of pyridinic‐NCo bonding, instead of pyrrolic‐N bonding, in synergistically promoting reversible oxygen electrocatalysis. Moreover, density functional theory calculations provide deep insights into the corresponding synergistic mechanism. The optimized hybrid, NiCo/NLG‐270, manifests outstanding reversible oxygen electrocatalytic activities, leading to an overpotential different ΔE among the lowest value for highly efficient bifunctional catalysts. In a practical reversible Zn–air battery, NiCo/NLG‐270 exhibits superior charge/discharge performance and long‐term durability compared to the noble metal electrocatalysts.

中文翻译：

确定吡啶-N-Co键在可逆ORR / OER协同电催化中的关键作用

对于许多再生电化学能量转换系统而言，包含过渡金属（TM）氧化物和杂原子掺杂（例如，氮掺杂）碳质材料的混合电催化剂有望成为双功能氧还原反应/放氧反应电催化剂，其增强的电催化活性归因于协同效应源自TM–N–C活性位点。然而，仍然不清楚的是，氮氧化物的掺杂物，无论是吡啶二酸还是吡咯N，当以氧化物形式与TM结合时，主要起协同作用。在本文中，描述了一种基于激光辐照的创新策略，以可控制地调节混合催化剂（即NiCo ₂ O _4）中吡啶和吡咯氮掺杂剂的相对浓度。NP / N掺杂介孔石墨烯。比较研究表明，在协同促进可逆氧电催化中，吡啶-NCo键而不是吡咯-N键起主要作用。此外，密度泛函理论计算为相应的协同机制提供了深刻的见解。经过优化的杂化NiCo / NLG-270具有出色的可逆氧电催化活性，从而在高效双功能催化剂的最低值中产生了超电势差ΔE。在实用的可逆锌空气电池中，与贵金属电催化剂相比，NiCo / NLG-270具有出众的充电/放电性能和长期耐久性。

更新日期：2018-04-20

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