Identifying the Key Role of Pyridinic-N-Co Bonding in Synergistic Electrocatalysis for Reversible ORR/OER
Identifying the Key Role of Pyridinic-N-Co Bonding in Synergistic Electrocatalysis for Reversible ORR/OER
复制标题
确定吡啶-N-Co 键合在可逆 ORR/OER 协同电催化中的关键作用
DOI：
10.1002/adma.201800005
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发表时间：
2018
影响因子：
29.4
通讯作者：
Jing Yang
中科院分区：
文献类型：
--
作者：
Xue-Rui Wang;Jie-Yu Liu;Zi-Wei Liu;Wei-Chao Wang;Jun Luo;Xiao-Peng Han;Xi-Wen Du;Shi-Zhang Qiao;Jing Yang
对于许多再生型电化学能量转换系统，由过渡金属氧化物和杂原子掺杂（如氮掺杂）碳质材料组成的杂化电催化剂是很有前途的双功能氧还原反应/析氧反应电催化剂，其电催化活性的增强是由于TM - n - c活性位点产生的协同效应。然而，当氮掺杂剂（吡啶氮或吡啶氮）在氧化物中与TM结合时，哪种构型对协同效应起主要作用仍然是不明确的。本文描述了一种基于激光照射的创新策略，以可控地调节杂化催化剂中吡啶和吡啶氮掺杂剂的相对浓度，即NiCo2O4NPs/N掺杂介孔石墨烯。对比研究表明，吡啶- N - Co键在协同促进可逆氧电催化中起主导作用，而不是吡啶- N键。此外，密度泛函理论计算为相应的协同机制提供了深入的见解。优化后的混合物NiCo/NLG‐270表现出出色的可逆氧电催化活性，导致过电位不同ΔEamong，这是高效双功能催化剂的最低值。在实际的可逆锌空气电池中，NiCo/NLG‐270与贵金属电催化剂相比，具有优越的充放电性能和长期耐用性。
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., NiCo2O4NPs/N‐doped mesoporous graphene. Comparative studies reveal the dominant role of pyridinic‐NCo 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 ΔEamong 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.