通过构建氧化物阻层,高碳耐受性基催化剂
Tao Wang1, Lai-Yang Li1, Li-Na Chen1
1Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory of Physical Chemistry of Solid Surfaces, Tan Kah Kee Innovation Laboratory, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, PR China.
Journal of the American Chemical Society
|May 20, 2022
概括
在二氧化 (Ru@RuO2/TiO2) 上涂上氧化的新型催化剂显示出对燃料电池中一氧化碳 (CO) 毒害的优越耐受性. 这一突破提高了电氧化催化剂的稳定性和寿命.
科学领域:
- 材料科学
- 电化学
- 催化剂
背景情况:
- 一氧化碳 (CO) 中毒严重限制了组金属催化剂的性能和耐用性,特别是在氧化反应期间的质子交换膜燃料电池中.
- 开发耐碳电催化剂对于推进燃料电池技术和实现广泛采用至关重要.
研究的目的:
- 设计和研究一种新型的催化剂,可增强对电氧化中毒的耐受性.
- 阐明新催化剂系统中观察到的CO耐受性背后的机制.
主要方法:
- 用二氧化 (Ru@RuO2/TiO2) 支持的氧化涂层的纳米颗粒的合成.
- 使用旋转盘电极 (RDE) 进行电化学测试,以评估电氧化活性和CO耐受性.
- 在1%的CO/H2环境中长时间进行稳定性测试.
- 开始分子动力学 (AIMD) 模拟以了解在原子层面的CO吸附和扩散行为.
主要成果:
- 与传统的PtRu/C催化剂相比,Ru@RuO2/TiO2催化剂表现出对1-3%的CO耐受性,大约提高了两倍.
- 催化剂在1%的CO/H2中经过50个小时的稳定运行,即使在纯碳中,大约20%的活性部位仍然具有功能.
- AIMD模拟显示,含水金属氧化物外有效阻断CO吸附,而不是促进CO氧化,抑制CO扩散和吸附通过封闭的水.
结论:
- Ru@RuO2/TiO2催化剂为电氧化提供了显著的 CO 耐受性.
- 耐氧化碳机制归因于氧化物阻层,而不是双功能活动.
- 这种氧化物阻断层方法为设计下一代高碳耐受性燃料电池电催化剂提供了有希望的策略.
相关概念视频
02:47Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
19.0K
Introduction
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
19.0K
02:44Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
10.9K
Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.
10.9K
02:36Regioselectivity and Stereochemistry of Hydroboration
8.4K
A significant aspect of hydroboration–oxidation is the regio- and stereochemical outcome of the reaction.
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn...
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn...
8.4K