一氧化碳在纳米粒子上的尺寸依赖性解离
Anders Tuxen1, Sophie Carenco, Mahati Chintapalli
1Material Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.
Journal of the American Chemical Society
|January 24, 2013
概括
在纳米颗粒上的一氧化碳解离是尺寸依赖和辅助的. 较大的纳米颗粒 (15纳米) 显示出更高的一氧化碳解离效率,这对于费舍尔-托普施合成至关重要.
科学领域:
- 表面科学是一门科学.
- 纳米粒子催化剂的作用
- 不同质的化学不同质的化学.
背景情况:
- 一氧化碳 (CO) 在金属纳米颗粒上的吸附和解离对于催化过程至关重要.
- 纳米粒子是相关的催化剂,特别是在菲舍-托普施合成中.
- 了解影响二氧化碳解离的因素对于催化剂设计至关重要.
研究的目的:
- 研究一氧化碳在不同尺寸 (4-15纳米) 的纳米颗粒上的吸附和解离.
- 为了确定纳米粒子大小和共同暴露对CO分离的影响.
- 为了阐明纳米颗粒在催化应用中的解离中的作用.
主要方法:
- 在现场使用软X射线吸收光谱法 (XAS).
- 对控制尺寸 (4nm和15nm) 的纳米粒子进行了研究.
- 在不同的条件下监测反应,包括暴露.
主要成果:
- 碳主要在纳米颗粒上以分子吸附,其中一些经历分离吸附以形成氧化物种.
- 与较小的 (4 nm) 相比,较大的纳米颗粒 (15 nm) 的CO分离效率显著更高.
- 暴露于气会极大地增加二氧化碳解离率,这表明了气辅助解离.
结论:
- 纳米颗粒大小极大地影响了CO分离,较大的颗粒更具反应性.
- 在促进纳米颗粒上的二氧化碳解离中发挥着至关重要的作用.
- 纳米粒子解离的能力是控制它们在费舍-托普施合成中的反应性的关键因素.
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