Hydrogen production through proton exchange membrane water electrolyzers (PEMWE) requires more active and stable electrocatalysts in acidic media. Herein, a class of Ir‐based alloys is reported with flower‐like structure as excellent electrocatalysts both for hydrogen and oxygen generation in acid. Specially, the IrNi alloy nanoflowers (IrNi NFs) present the best hydrogen evolution reaction (HER) performance, revealed by a low Tafel slope and overpotential at current density of 10 mA cm⁻², exceeding the commercial Pt/C. It is discovered that alloying Ir with Ni can decrease the hydrogen binding energy (HBE) of Ir metal, resulting in almost 2.5 times increase in the HER intrinsic activity of IrNi NFs than Ir NFs. The IrNi NFs catalyst is also highly efficient in oxygen evolution reaction with mass activity of 379 A g⁻¹ Ir at 1.51 V versus reversible hydrogen electrode. Furthermore, the overall water‐splitting devices using the IrNi NFs as catalysts for both cathode and anode show a low cell voltage of 1.60 V at 10 mA cm⁻² and long‐term stability within 1000 cycles. This work uncovers that HBE optimization is the key of enhancing HER activity on Ir‐based alloys and these Ir‐based NFs hold great promise in future application in the PEMWE.

中文翻译：

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具有最佳氢键结合能的Ir基合金纳米花作为双功能电催化剂，可用于总水分解

通过质子交换膜水电解器（PEMWE）产生氢气需要在酸性介质中具有更活泼和稳定的电催化剂。在本文中，据报道一类具有花状结构的Ir基合金是在酸中产生氢气和氧气的出色电催化剂。特别是，IrNi合金纳米花（IrNi NFs）表现出最佳的氢气释放反应（HER）性能，其低Tafel斜率和在10 mA cm ^-2的电流密度下的超电势所揭示，超过了商业Pt / C。发现将Ir与Ni合金化可以降低Ir金属的氢键能（HBE），导致IrNi NFs的HER本征活性几乎是Ir NFs的2.5倍。与可逆氢电极相比，IrNi NFs催化剂在氧气逸出反应中也非常高效，在1.51 V下的质量活度为379 A g ^-1 Ir。此外，使用IrNi NFs作为阴极和阳极催化剂的整体水分解装置在10 mA cm ^-2时显示1.60 V的低电池电压，并在1000次循环内具有长期稳定性。这项工作揭示了HBE优化是增强HER对Ir基合金的活性的关键，而这些Ir基NFs在PEMWE的未来应用中具有广阔的前景。