Abstract:

Perovskite oxides represent promising catalysts for the oxygen evolution reaction (OER). However, achieving high catalytic activity through efficient doping of B-site elements within stable perovskite oxides remains a challenge. By introducing defects at the A-site, enhanced adsorption of Fe ions in the electrolyte was promoted, leading to efficient doping of the B-site metal and the construction of a stable structure on the perovskite surface under applied voltage. The synthesized La_1-x Ni_1-y Fe _y O_3‑δ featured a rough nanospherical morphology, offering an increased electrochemically active surface area. The optimized incorporation of an external Fe source (FeCl₃) characterized by a smaller ionic radius facilitated more efficient doping and structural stability. The introduction of A-site defects and Fe doping led to an increase in oxygen vacancies at the B-site, which benefited the OER activity. At a current density of 10mA/cm², the material required only an overpotential of 345mV and demonstrated long-term durability over 68h. The A-site defect optimized adsorption of key oxygen intermediates and the B-site Fe doping modulates stronger Ni-O covalency. This strategy of synergistic regulation through A-site defect engineering and B-site metal doping offered a new approach to designing highly efficient alkaline OER catalysts.

Key words: optimization, doping, perovskite, oxygen evolution reaction, electrochemistry, catalyst

摘要：

钙钛矿氧化物是非常有潜力的析氧反应（OER）催化剂。然而，通过有效掺杂稳定钙钛矿氧化物中B位元素以实现高催化活性仍然是一大挑战。本文通过在A位引入缺陷，促进了电解液中Fe离子的强吸附，进而在施加电压下实现B位金属的高效掺杂及钙钛矿表面稳定结构的构筑。制备的La_1-x Ni_1-y Fe _y O_3‑δ 具有粗糙纳米球形貌，这提供了更大的电化学活性表面积。外部Fe源（FeCl₃）具有较小离子半径，更容易实现高效掺杂和结构稳定。A位缺陷的引入和B位Fe掺杂增加了La_1-x Ni_1-y Fe _y O_3‑δ 中的氧空位，有利于提升其析氧活性。在10mA/cm²的电流密度下，该催化剂仅需要345mV的过电位，就展示了超过68h的长期稳定性。这种通过A位缺陷工程与B位金属掺杂协同的调控策略，为设计高效碱性OER催化剂提供了新的方法。A位缺陷增强了关键氧中间体的吸附，B位Fe掺杂加强了Ni-O共价性。这种通过A位缺陷工程与B位金属掺杂协同的调控策略，为设计高效的碱性OER催化剂提供了新的方法。

关键词: 优化, 掺杂, 钙钛矿, 析氧反应, 电化学, 催化剂