Zhao Bolin, Liu Chuhao, Mahmood Azhar, Talib Shamraiz Hussain, Wang PengChong, He Ying, Qu Dongyang, Niu Li
Center for Advanced Analytical Science, Guangzhou Key Laboratory of Sensing Materials and Devices, Guangdong Engineering Technology Research Center for Photoelectric Sensing Materials and Devices, School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, P. R. China.
College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China.
ACS Appl Mater Interfaces. 2024 Jul 24;16(29):37829-37839. doi: 10.1021/acsami.4c03946. Epub 2024 Jul 16.
Platinum (Pt) has been widely used as cathodic electrocatalysts for the hydrogen evolution reaction (HER) but unfortunately neglected as an anodic electrocatalyst for the oxygen evolution reaction (OER) due to excessively strong bonding with oxygen species in water splitting electrolyzers. Herein we report that fine control over the electronic-structure and local-coordination environment of Pt-rich PtPbCu nanowires (NWs) by doping of iridium (Ir) lowers the overpotential of the OER and simultaneously suppresses the overoxidation of Pt in IrPtPbCu NWs during water electrolysis. In light of the one-dimensional morphology featured with atomically dispersed IrO species and electronically modulated Pt-sites, the IrPtPbCu NWs exhibit an enhanced OER (175 mV at 10 mA cm) and HER (25 mV at 10 mA cm) electrocatalytic performance in acidic media and yield a high turnover frequency. For OER at the overpotential of 250 mV, the IrPtPbCu NWs show an enhanced mass activity of 1.51 A mg (about 19 times higher) than Ir/C. For HER at the overpotential of 50 mV, NWs exhibit a remarkable mass activity of 1.35 A mg, which is 2.6-fold relative to Pt/C. Experimental results and theoretical calculations corroborate that the doping of Ir in NWs has the capacity to suppress the formation of Pt derivates and ameliorate the adsorption free energy of reaction intermediates during the water electrolysis. This approach enabled the realization of a previously unobserved mechanism for anodic electrocatalysts.
铂（Pt）已被广泛用作析氢反应（HER）的阴极电催化剂，但由于在水电解槽中与氧物种的结合过强，不幸被忽视作为析氧反应（OER）的阳极电催化剂。在此，我们报告通过铱（Ir）掺杂对富Pt的PtPbCu纳米线（NWs）的电子结构和局部配位环境进行精细控制，可降低OER的过电位，并同时抑制水电解过程中IrPtPbCu NWs中Pt的过氧化。鉴于具有原子分散的IrO物种和电子调制的Pt位点的一维形态，IrPtPbCu NWs在酸性介质中表现出增强的OER（10 mA cm时为175 mV）和HER（10 mA cm时为25 mV）电催化性能，并产生高周转频率。对于250 mV过电位下的OER，IrPtPbCu NWs的质量活性比Ir/C提高了1.51 A mg（约高19倍）。对于50 mV过电位下的HER，NWs表现出1.35 A mg的显著质量活性，相对于Pt/C为2.6倍。实验结果和理论计算证实，NWs中Ir的掺杂能够抑制Pt衍生物的形成，并改善水电解过程中反应中间体的吸附自由能。这种方法实现了阳极电催化剂以前未观察到的机制。
