在酸性水性条件下的电催化演变和高度稳定的分子催化剂的机制研究
1Department of Chemistry, University of California , Irvine, California 92697, United States.
Journal of the American Chemical Society
|July 15, 2016
概括
一个稳定的复合物[Ni(DHMPE) 2+在酸性条件下有效催化演化反应 (HER). 这种同质的催化剂表现出高稳定性和活性,使得改善电催化剂的详细机制研究成为可能.
科学领域:
- 电化学
- 催化剂
- 有机金属化学
背景情况:
- 进化反应对于可持续能源技术至关重要.
- 特别是在酸性介质中开发稳定高效的同质催化剂仍然是一个重大挑战.
- 复合物可能是贵金属催化剂的成本效益替代品.
研究的目的:
- 报告水溶性复合物的电催化活性,Ni ((DHMPE) 2) 2+,对于pH 1的HER.
- 在酸性条件下研究这种催化剂的稳定性和机械路径.
- 通过化合物和催化剂中间体的稳定性进行详细的机制研究.
主要方法:
- 在pH1下使用复合物 ([Ni(DHMPE) 2+) 的电催化.
- 在长时间电解 (18小时以上) 之前和之后对复合物的量化.
- 对电子和质子转移进行热力学参数分析.
- 反应中间体的光谱识别.
主要成果:
- [Ni(DHMPE) 2+复合体具有高的催化活性 (k_obs ~10^3 s^-1) 和HER的法拉第效率.
- 在电解18个小时后观察到催化剂的微不足道分解,表明在酸性条件下具有很好的稳定性.
- 详细的机制研究使得主要中间体的光谱识别成为可能.
结论:
- 溶于水的复合物[Ni(DHMPE) 2+ 是一种高稳定性和活性的同质催化剂,用于pH1的演变反应.
- 在酸性条件下观察到的稳定性对于均的HER催化剂来说是罕见的.
- 机理学研究表明一种涉及两个电子的减少路径,其次是连续的质子化步骤.
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