High-Valent Nickel Promoted by Atomically Embedded Copper for Efficient Water Oxidation
High-Valent Nickel Promoted by Atomically Embedded Copper for Efficient Water Oxidation
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原子嵌入铜促进高价镍实现高效水氧化
DOI：
10.1021/acscatal.0c01733
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发表时间：
2020-09-04
期刊：
影响因子：
12.9
通讯作者：
Liang, Hongyan
中科院分区：
文献类型：
--
作者：
Han, Mei;Wang, Ning;Liang, Hongyan
高效、低成本的析氧反应（OER）电催化剂，特别是在中性条件下，对二氧化碳减排和海水分解电解等可再生能源技术具有重要意义。高价过渡金属位被认为是OER活性位；然而，这些场地的合理设计和施工仍然是一个很大的挑战。本文报道了一种三金属NiFeCu氢氧化物电催化剂，通过x射线光电子能谱和x射线吸收光谱证实，原子嵌入的Cu促进并稳定了高价Ni位点。通过成分优化，Ni6Fe1Cu1催化剂在10 mA cm（-2）时的过电位为385 mV， Tafel斜率为164 mV dec(-1)，在pH = 7.2时的稳定性为100 h。密度泛函理论计算表明，cu掺杂通过调节Ni的d带中心，降低催化剂表面含氧中间体的吸附能，促进了高价Ni的形成，从而促进了OER电催化。本研究为通过包埋氧化还原活性金属来构建所需的高价金属OER催化剂铺平了一条有希望的道路。
Efficient and low-cost electrocatalysts for oxygen evolution reaction (OER), particularly in neutral conditions, are of significant importance for renewable energy technologies such as CO2 reduction and seawater splitting electrolysis. High-valent transition-metal sites have been considered as OER active sites; however, the rational design and construction of these sites remain a big challenge. Here, we report a trimetallic NiFeCu oxyhydroxide electrocatalyst, in which high-valent Ni sites are promoted and stabilized by the atomically embedded Cu, as evidenced by X-ray photoelectron spectroscopy and X-ray absorption spectroscopy. Through compositional optimization, Ni6Fe1Cu1 catalysts achieved an overpotential of 385 mV at 10 mA cm(-2), a Tafel slope of 164 mV dec(-1), and a stability of 100 h at pH = 7.2. Density function theory calculations demonstrated that the Cu-doping facilitates the formation of high-valent Ni and thus promotes OER electrocatalysis through modulating the d-band center of Ni and reducing the adsorption energy of oxygenated intermediates on the surface of the catalyst. This work paves a promising avenue for the construction of desired high-valent metal OER catalysts by embedding redox inactive metals.