实现多态碳酸催化剂的相位控制
Sinhara M H D Perera1, Eva Ciuffetelli1, Marc D Porosoff1
1Department of Chemical and Sustainability Engineering, University of Rochester, Rochester, New York 14627, United States.
概括
这项研究提出了一种新方法,通过控制碳化动力学来合成纯碳化 (WxC) 阶段. 这使得可调节的碳化物催化剂具有增强的活性,用于逆水气转移反应.
科学领域:
- 材料科学 材料科学 材料科学
- 催化剂是一种催化剂.
- 化学工程是化学工程的重要组成部分.
背景情况:
- 碳化 (WxC) 呈现阶段多态性,复杂化了在催化过程中的结构属性关系研究.
- 纯WxC相的选择性合成对于理解和优化催化性能至关重要.
研究的目的:
- 通过控制碳化动力学来建立WxC的阶段选择性合成框架.
- 研究WOx碳化过程的机械路径和粒子大小的作用.
- 评估合成的β-W2C的催化活性和稳定性,用于逆水气转移 (RWGS) 反应.
主要方法:
- 使用温度编程碳化 (TPC) 与气态碳前体 (CH4 / H2) 的 WxC 的阶段选择性合成.
- 控制的粒子大小 (<10 nm) 来稳定β-W2C.
- 通过CH4激活,阐明WOx碳化过程的机制.
- 反应堆研究比较RWGS的*ex situ*和*in situ*合成的β-W2C.
主要成果:
- 通过控制粒子大小和碳化动力学来实现β-W2C的选择性合成.
- W2C稳定主要由粒子大小和动力学决定,而不是支持相互作用.
- 在WOx碳化过程中,CH4激活在温和的温度下通过晶格氧发生.
- *在现场*合成的β-W2C与*在现场*合成的催化剂和其他WxC相比,在RWGS中显示出更高的CO选择性和产量 (STY).
结论:
- 建立了一种可调节的方法来合成相纯碳化物催化剂.
- 证明了β-W2C对RWGS的内在活性,特别是当*in situ*合成时.
- 了解碳化动力学和粒子大小控制是优化WxC催化剂设计的关键.
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