Tuning of Trifunctional NiCu Bimetallic Nanoparticles Confined in a Porous Carbon Network with Surface Composition and Local Structural Distortions for the Electrocatalytic Oxygen Reduction, Oxygen and Hydrogen Evolution Reactions
Tuning of Trifunctional NiCu Bimetallic Nanoparticles Confined in a Porous Carbon Network with Surface Composition and Local Structural Distortions for the Electrocatalytic Oxygen Reduction, Oxygen and Hydrogen Evolution Reactions
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DOI：
10.1021/jacs.0c06960
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发表时间：
2020-08-26
影响因子：
15
通讯作者：
Noveron, Juan C.
中科院分区：
文献类型：
--
作者：
Ahsan, Md Ariful;Santiago, Alain R. Puente;Noveron, Juan C.
使用非贵金属促进H2-、O2-、O-和H2O之间的相互转化的多功能催化剂的合理设计是一个激烈的研究领域。双金属纳米系统具有高度可调的电子，结构和催化性能，这取决于它们的组成，结构和尺寸引起了相当大的关注。在此，我们报道了限制在sp（2）碳骨架中的镍铜（NiCu）合金纳米颗粒的合成，其对析氢（HER）、氧还原（ORR）和析氧（OER）反应表现出三功能催化性能。NiCu纳米合金的电催化功能的实验和理论相关的组成依赖的局部结构畸变的纳米颗粒表面的晶格。我们的研究表明，下调的d-带的催化剂，调整的结合能的中间催化物种。XPS分析表明，Ni 0.25Cu 0.75/C纳米颗粒的Ni 2 p（3/2）带的结合能与其他双金属体系相比移动了约3倍，这与观察到的高电催化活性相关。有趣的是，Ni0.25Cu0.75/C催化剂超过了RuO 2基准催化剂的OER性能，表现出相对于RHE的1.44 V的小起始电位和在10 www.example.com（-2）下400 mV的过电位mA.cm，以及商业RuO 2和Pt催化剂的电化学长期稳定性，并保持至少90%。OER/ORR/HER反应在20 000 s后施加初始电流的1/4。这项研究揭示了具有多功能电催化性能的非贵金属双金属纳米结构的结构-功能关系的重要见解。
The rational design of multifunctional catalysts that use non-noble metals to facilitate the interconversion between H-2, O-2,O- and H2O is an intense area of investigation. Bimetallic nanosystems with highly tunable electronic, structural, and catalytic properties that depend on their composition, structure, and size have attracted considerable attention. Herein, we report the synthesis of bimetallic nickel-copper (NiCu) alloy nanoparticles confined in a sp(2) carbon framework that exhibits trifunctional catalytic properties toward hydrogen evolution (HER), oxygen reduction (ORR), and oxygen evolution (OER) reactions. The electrocatalytic functions of the NiCu nanoalloys were experimentally and theoretically correlated with the composition-dependent local structural distortion of the bimetallic lattice at the nanoparticle surfaces. Our study demonstrated a downshift of the d-band of the catalysts that adjusts the binding energies of the intermediate catalytic species. XPS analysis revealed that the binding energy for Ni 2p(3/2) band of the Ni0.25Cu0.75/C nanoparticles was shifted similar to 3 times compared to other bimetallic systems, and this was correlated to the high electrocatalytic activity observed. Interestingly, the bimetallic Ni0.25Cu0.75/C catalyst surpassed the OER performance of RuO2 benchmark catalyst exhibiting a small onset potential of 1.44 V vs RHE and an overpotential of 400 mV at 10 mA.cm(-2) as well as the electrochemical long-term stability of commercial RuO2 and Pt catalysts and kept at least 90% of the initial current applied after 20 000 s for the OER/ORR/HER reactions. This study reveals significant insight about the structure- function relationship for non-noble bimetallic nanostructures with multifunctional electrocatalytic properties.