ACS Appl Mater Interfaces. 2018 Jun 13;10(23):19746-19754. doi: 10.1021/acsami.8b05353. Epub 2018 Jun 4.
The oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) properties of double perovskite catalysts LaCoMnO and LaNiMnO have been investigated. The experimental results demonstrate that these samples are efficient OER and ORR catalysts. For the LaCoMnO compound annealed at 600 °C, its half-wave potential of ORR in alkaline media is as low as 0.75 V versus reversible hydrogen electrode. As for the correlation between electrocatalytic activities and the e orbital occupation numbers, it is found that the e-filling rule proposed by Shao-Horn and co-workers is valid in LaCoMnO when the e electrons of two kinds of transition-metal ions are all considered. In the case of LaNiMnO, because the samples which prepared in different conditions all have unity average e occupation, the e-filling rule should be amended. We suggest that the average deviation from unity e occupation is a suitable activity descriptor, which can be used to design perovskite catalysts with unity average e occupation.
研究了双钙钛矿催化剂 LaCoMnO 和 LaNiMnO 的析氧反应 (OER) 和氧还原反应 (ORR) 性能。实验结果表明，这些样品是高效的 OER 和 ORR 催化剂。对于在 600°C 下退火的 LaCoMnO 化合物，其在碱性介质中的 ORR 半波电位低至相对于可逆氢电极的 0.75V。至于电催化活性与 e 轨道占据数之间的关系，发现 Shao-Horn 及其同事提出的 e 填充规则在考虑两种过渡金属离子的 e 电子时在 LaCoMnO 中是有效的。对于 LaNiMnO，由于在不同条件下制备的样品的平均 e 占据数均为 1，因此 e 填充规则应该进行修正。我们建议，平均偏离 unity e 占据数是一个合适的活性描述符，可用于设计具有 unity e 占据数的钙钛矿催化剂。
