硼掺杂无定形氧化铱增强酸性析氧反应质量活性

Boron-doped amorphous iridium oxide with ultrahigh mass activity for acidic oxygen evolution reaction

析氧反应(OER)作为一种主要的阳极反应,在许多电化学能量转换过程中起到了重要的作用.尽管铱(Ir)基材料是目前最先进的OER催化剂,其稀缺性很大程度上限制了该类材料的实际应用.在此,我们利用简便的硼酸辅助法成功制备了硼掺杂的无定形氧化铱(IrO_(x)-B).该催化剂在300 mV过电位处展现出2779 A g^(-1)的超高OER质量活性,是已报道的最佳酸性OER催化剂之一.我们发现硼酸不仅可以促进Ir位点的暴露,还能够以偏硼酸根的形式掺杂进入无定形Ir O_(x)中,并进一步优化Ir的电子与配位结构,进而实现本征活性的提升.有趣的是,这种方法具有一定的普适性,能够提升其他金属氧化物催化剂的OER催化活性.这为制备高质量活性的OER电催化剂提供了一种通用的策略.

Oxygen evolution reaction(OER), as the primary anodic reaction, plays a critical role in many electrochemical energy conversion processes. As the state-of-the-art OER catalysts, iridium-based materials are largely hindered from practical applications mainly due to the extreme scarcity of iridium. Here we demonstrate the successful fabrication of boron-doped amorphous iridium oxide(IrO_(x)-B) via a facile boric acid-assisted method, which realizes an ultrahigh OER mass activity of 2779 A g^(-1)Irat 300 mV overpotential, representing one of the best acidic OER catalysts reported so far.It is found that boric acid can not only facilitate the exposure of Ir, but also dope the amorphous IrOxwith a form of metaborate, which could further modify the electronic and local ligand structure of Ir for the improved intrinsic activity. Interestingly, the reported strategy is universal that can be applied to improve other metal oxide OER catalysts, highlighting a versatile strategy for creating high-performance electrocatalysts with ultrahigh mass activity for OER and beyond.