在氧化脱条件下探测化催化剂的转化
Alyssa M Love1, Brijith Thomas2, Sarah E Specht1
1Department of Chemistry , University of Wisconsin - Madison , 1101 University Avenue , Madison , Wisconsin 53706 , United States.
Journal of the American Chemical Society
|December 12, 2018
概括
在氧化脱条件下,六角化和化纳米管形成了强大的B ((OH) xO3-x氧化阶段. 这一发现修改了关于这些材料活性催化位点的先前假设.
科学领域:
- 材料科学
- 催化剂
- 表面化学
背景情况:
- 六角化物 (h-BN) 和化物纳米管 (BNNT) 对氧化脱 (ODH) 的选择性很高.
- 表面氧含量在ODH后显著增加,但氧化的物种仍然不明.
- 之前的假设建议化BN边缘作为活性催化位点.
研究的目的:
- 在催化ODH后,阐明在h-BN和BNNT上形成的氧化物种的分子结构.
- 修订现有的BN催化ODH反应中的活性位点的理解.
主要方法:
- 先进的核磁共振 (NMR) 光谱.
- 扫描电子显微镜 (SEM).
- 软X射线吸收光谱 (XAS).
主要成果:
- 在ODH条件下,原始BN材料会氧化和水解.
- 一种稳定的B(OH) xO3-x相形式,具有不同基和桥接氧基的三坐标 (x = 0-3).
- 这种强的氧化物阶段被确定为占主导地位的物种,挑战了先前的假设.
结论:
- 在ODH的h-BN和BNNT催化中的活性相是B(OH) xO3-x氧化物,而不仅仅是化边缘.
- 这项研究提供了对ODH反应中基于BN的催化剂的修订分子层面的理解.
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