电化学驱动的水氧化催化,从六个示例的多金属酸盐开始:它是分子,均的催化或电极结合,异质的COO
Scott J Folkman1, Joaquin Soriano-Lopez2, José Ramón Galán-Mascarós2
1Chemistry Department , Colorado State University , Fort Collins , Colorado 80523 , United States.
Journal of the American Chemical Society
|September 12, 2018
概括
在水氧化催化 (WOCatalysis) 方面研究了六种多氧金属酸盐 (Co-POM) 预催化剂. 结果表明,虽然一些Co-POMs形成异质氧化物 (CoO x) 催化剂,但另一些则作为分子Co-POM水氧化催化剂 (WOCatalysts) 起作用.
科学领域:
- 无机化学
- 电化学
- 催化剂
背景情况:
- 作为潜在的分子水氧化催化剂 (WOCatalysts),研究的是多氧金属酸盐 (Co-POMs).
- 一个关键的问题是Co-POM是否作为真正的分子催化剂,或者在水氧化催化 (WOCatalysis) 条件下分解为异质氧化物 (CoOx) 物种.
研究的目的:
- 为了确定六个示例Co-POM是否作为分子WOC催化剂或在电化学驱动的WOC催化下形成异质CoOx.
- 在不同的pH条件 (5.8,8.0和9.0) 中评估这些Co-POM的稳定性和催化活性.
主要方法:
- 在pH 5.8,8.0和9.0下使用六种不同的Co-POM进行了WOCatalysis的研究.
- 通过31P NMR线路扩展和阴极剥离,量化了随着时间的推移形成的水性离子 (Co) 量.
- 与观察到的 WOC 催化活性相关联.
主要成果:
- 对于大多数 Co-POM/pH 组合,检测到的 Co ((II) aq 占异质 CoO x 的形成,这是 WOC 催化物的原因.
- 然而,在特定条件下 (0. 1M NaPi,pH 5. 8),CoPW11和α1-CoP2W17显示了WOC催化活性,不能归因于可检测的Co(II) aq,这表明分子Co-POM催化.
- 即使是最稳定的Co-POM,α1-CoP2W17,与异质的CoO x相比,其作为分子催化剂的活性也明显较低.
结论:
- 根据特定的Co-POM结构和反应条件,Co-POM可以作为分子WOC催化剂或异质CoOx催化剂的前体.
- 在pH 5. 8的酸盐缓冲条件下,CoPW11和α1-CoP2W17主要作为分子Co-POM WOCatalysts的功能.
- 不同质的CoOx物种通常比它们的分子Co-POM前体更活跃的水氧化催化剂.
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