Torsion strained iridium oxide for efficient acidic water oxidation in proton exchange membrane electrolyzers
Torsion strained iridium oxide for efficient acidic water oxidation in proton exchange membrane electrolyzers
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DOI：
10.1038/s41565-021-00986-1
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发表时间：
2021-10-25
影响因子：
38.3
通讯作者：
Jin, Song
中科院分区：
文献类型：
--
作者：
Hao, Shaoyun;Sheng, Hongyuan;Jin, Song
具有丰富晶界的扭应变TaxTmyIr 1-x-yO 2-delta纳米催化剂在实际质子交换膜电解槽中具有酸性析氧的前景。酸性析氧反应是质子交换膜水裂解电解槽实用化的关键，但高催化过电位和贵金属催化剂的高负载量阻碍了酸性析氧反应。在这里，我们提出了一个扭转应变的Ta0.1Tm0.1Ir0.8O2-δ纳米催化剂与众多的晶界，表现出198 mV的低过电位在10 mA cm（-2）对析氧反应在0.5 M H2SO 4。微观结构分析、X射线吸收光谱和理论计算表明，晶界之间的协同效应导致Ir-O键的扭转应变和掺杂诱导的配体效应共同调节了氧中间体的吸附能，从而提高了催化活性。使用具有0.2 mg cm（-2）的低质量负载的Ta 0.1Tm 0.1Ir 0.8O2-delta纳米催化剂的质子交换膜电解器可以在1.5 A cm（-）（2）下稳定地操作500小时，估计每千克H-2的成本为1美元，这远低于美国能源部设定的目标（每千克H-2 2美元）。
Torsion-strained TaxTmyIr1-x-yO2-delta nanocatalyst with abundant grain boundaries is promising towards acidic oxygen evolution in practical proton exchange membrane electrolysers. The cost of H-2 is estimated to be reduced to US$1 per kg.Acidic oxygen evolution reaction is crucial for practical proton exchange membrane water splitting electrolysers, which have been hindered by the high catalytic overpotential and high loading of noble metal catalysts. Here we present a torsion-strained Ta0.1Tm0.1Ir0.8O2-delta nanocatalyst with numerous grain boundaries that exhibit a low overpotential of 198 mV at 10 mA cm(-2) towards oxygen evolution reaction in 0.5 M H2SO4. Microstructural analyses, X-ray absorption spectroscopy and theoretical calculations reveal that the synergistic effects between grain boundaries that result in torsion-strained Ir-O bonds and the doping induced ligand effect collectively tune the adsorption energy of oxygen intermediates, thus enhancing the catalytic activity. A proton exchange membrane electrolyser using a Ta0.1Tm0.1Ir0.8O2-delta nanocatalyst with a low mass loading of 0.2 mg cm(-2) can operate stably at 1.5 A cm(-)(2) for 500 hours with an estimated cost of US$1 per kilogram of H-2, which is much lower than the target (US$2 per kg of H-2) set by the US Department of Energy.