Sun Chongyun, Qin Jiaqi, Li Mengyao, Han Guangqi, Song Yujiang
State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, 2 Linggong Road, Dalian116024, People's Republic of China.
Inorg Chem. 2022 Oct 31;61(43):17362-17369. doi: 10.1021/acs.inorgchem.2c03101. Epub 2022 Oct 20.
Proton exchange membrane water electrolyzers (PEMWEs) are capable of mass-producing green hydrogen with renewable and wave-trough electricity, but confront the challenge of the lack of advanced electrocatalysts to accelerate sluggish oxygen evolution reaction (OER). Herein, we report the synthesis of ultrafine IrRu alloy nanoparticles (1.6 ± 0.3 nm) by coprecipitation of IrCl, RuCl, and HCOONa in water to allow Ir and Ru to be well dispersed and enclosed in the matrix of crystalline HCOONa, followed by heat treatment of HCOONa to reduce Ir and Ru. Remarkably, the overpotential of IrRu toward acidic OER at 10 mA cm is merely 230 and 194 mV at 51 and 204 μg cm, respectively. The high electrochemically active surface area (ECSA) of 577.1 m g and high specific activity (SA) of 22.7 μA cm at 1.45 V vs RHE would contribute to the exceptional OER activity. In addition, the electron transfer from Ir to Ru in IrRu should significantly boost the OER activity according to X-ray photoelectron spectroscopy (XPS). IrRu also shows an excellent stability during 10 h of a chronopotentiometry (CP) test at 10 mA cm. Eventually, the high OER activity of IrRu was verified in a PEMWE.
质子交换膜水电解槽（PEMWEs）能够利用可再生和低谷电力大规模生产绿色氢气，但面临着缺乏先进电催化剂来加速缓慢析氧反应（OER）的挑战。在此，我们报道了通过在水中将IrCl、RuCl和HCOONa共沉淀来合成超细IrRu合金纳米颗粒（1.6±0.3 nm），使Ir和Ru充分分散并包裹在结晶HCOONa的基质中，随后对HCOONa进行热处理以还原Ir和Ru。值得注意的是，IrRu在10 mA cm下对酸性OER的过电位在51和204 μg cm时分别仅为230和194 mV。在相对于可逆氢电极（RHE）为1.45 V时，577.1 m g的高电化学活性表面积（ECSA）和22.7 μA cm的高比活性（SA）将有助于其优异的OER活性。此外，根据X射线光电子能谱（XPS），IrRu中从Ir到Ru的电子转移应显著提高OER活性。在10 mA cm下进行10小时的计时电位法（CP）测试期间，IrRu也表现出优异的稳定性。最终，IrRu在PEMWE中验证了其高OER活性。
