Li Guoqiang, Li Kai, Yang Long, Chang Jinfa, Ma Rongpeng, Wu Zhijian, Ge Junjie, Liu Changpeng, Xing Wei
University of Chinese Academy of Sciences , Beijing 100039 , China.
ACS Appl Mater Interfaces. 2018 Nov 7;10(44):38117-38124. doi: 10.1021/acsami.8b14172. Epub 2018 Oct 29.
Reducing the noble-metal loading without sacrificing the catalytic performance of the oxygen evolution reaction (OER) catalysts is paramount yet highly challenging. Herein, IrO@Ir/TiN electrocatalysts employing TiN as the support have been developed and shown high efficiency toward OER. TiN is found not only to disperse the IrO@Ir nanoparticles effectively but also to exert the electronic modulation of Ir by downshifting its d-band center of 0.21 eV compared to pure IrO. Excitingly, TiN remarkably enhances the catalytic performance of Ir, where the overpotential to achieve the current density of 10 mA cm is only 265 mV for the IrO@Ir/TiN (60 wt %) catalyst. As a result, 71.7 wt % of the Ir metal can be saved to compare with the commercial Ir-black counterpart. Moreover, TiN can inhibit the aggregation and oxidative dissolution of Ir species, thereby enhancing the operational stability. The combined advantages of TiN open a new solution to reduce the anodic catalyst cost through boosting the catalytic activity and stability.
在不牺牲析氧反应（OER）催化剂催化性能的前提下降低贵金属负载量至关重要，但极具挑战性。在此，已开发出以TiN为载体的IrO@Ir/TiN电催化剂，并显示出对OER的高效性。研究发现，TiN不仅能有效分散IrO@Ir纳米颗粒，还能通过将其d带中心比纯IrO下移0.21 eV对Ir进行电子调制。令人兴奋的是，TiN显著提高了Ir的催化性能，对于IrO@Ir/TiN（60 wt%）催化剂，实现10 mA cm电流密度的过电位仅为265 mV。结果，与商业Ir黑相比，可节省71.7 wt%的Ir金属。此外，TiN可抑制Ir物种的聚集和氧化溶解，从而提高操作稳定性。TiN的综合优势为通过提高催化活性和稳定性降低阳极催化剂成本开辟了新的解决方案。
