The selective oxygen reduction reaction (ORR) is important for various energy conversion processes such as the fuel cells and metal-air batteries for the 4e⁻ pathway and hydrogen peroxide (H₂O₂) electrosynthesis for the 2e⁻ pathway. However, it remains a challenge to tune the ORR selectivity of a catalyst in a controllable manner. Herein, an efficient strategy for introducing sulfur dopants to regulate the ORR selectivity of main-group Sb−N−C single-atom catalysts is reported. Significantly, Sb−N−C with the highest sulfur content follows a 2e⁻ pathway with high H₂O₂ selectivity (96.8%) and remarkable mass activity (96.1 A g⁻¹ at 0.65 V), while the sister catalyst with the lowest sulfur content directs a 4e⁻ pathway with a half-wave potential (E_1/2 = 0.89 V) that is more positive than commercial Pt/C. In addition, practical applications for these two 2e⁻/4e⁻ ORR catalysts are demonstrated by bulk H₂O₂ electrosynthesis for the degradation of organic pollutants and a high-power zinc-air battery, respectively. Combined experimental and theoretical studies reveal that the excellent selectivity for the sulfurized Sb−N−Cs is attributed to the optimal adsorption-desorption of the ORR intermediates realized through the electronic structure modulation by the sulfur dopants.

中文翻译：

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用于选择性 2 电子和 4 电子氧还原的硫调节主族 Sb−N−C 催化剂

选择性氧还原反应（ORR）对于各种能量转换过程非常重要，例如用于4e ^-途径的燃料电池和金属-空气电池以及用于2e ^-途径的过氧化氢（H ₂ O ₂ ）电合成。然而，以可控方式调节催化剂的 ORR 选择性仍然是一个挑战。本文报道了一种引入硫掺杂剂来调节主族 Sb−N−C 单原子催化剂 ORR 选择性的有效策略。值得注意的是，硫含量最高的Sb−N−C遵循2e−^途径，具有高H ₂ O ₂选择性（96.8％）和显着的质量活性（0.65 V时为96.1 A g ⁻¹），而硫含量最低的姐妹催化剂硫含量引导 4e ⁻路径，其半波电位 ( E _1/2 = 0.89 V) 比商业 Pt/C 更正。此外，这两种2e ^- /4e ^{- ORR催化剂的实际应用分别通过用于有机污染物降解的本体H} ₂ O ₂电合成和高功率锌空气电池得到证实。结合实验和理论研究表明，硫化Sb−N−Cs的优异选择性归因于通过硫掺杂剂的电子结构调制实现的ORR中间体的最佳吸附-解吸。