通过在多氧金属-有机框架架构中的脱解来实现原子精确的单位催化剂
Zhihengyu Chen1, S M Gulam Rabbani2, Qin Liu3,4
1Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States.
Journal of the American Chemical Society
|March 14, 2024
概括
我们通过在金属有机框架 (MOF) 中嵌入多氧金属集群 (POM) 来开发具有高负载的耐烧结单位催化剂 (SSC). 这种双重封闭策略使得强大的,孤立的活性点能够进行先进的催化.
科学领域:
- 材料科学
- 催化剂
- 纳米技术
背景情况:
- 单位催化剂 (SSC) 通过原子分散的活性点提供高性能.
- 活跃物种的聚合和烧结是关键的挑战,通常通过较低的现场负载来缓解.
- 低站点负载限制SSC的表征技术.
研究的目的:
- 开发具有高负载的耐烧结SSC.
- 在多氧金属 (POMs) 和金属有机框架 (MOFs) 中使用双重封闭.
- 能够对孤立的活跃地点进行详细的结构特征.
主要方法:
- 将安德森-埃文斯POM (MMo6O24,M=Rh/Pt) 纳入基于Zr的MOF (NU-1000) 中.
- 在激活过程中从MOF中的POM中脱离贵金属部位.
- 在位射线散射与对分布函数 (PDF) 分析用于结构评估.
- 补充计算和X射线吸收光谱 (XAS).
主要成果:
- 实现了高负载 (高达3.2%重量) 的耐烧结SSC.
- 从POM和MOF结构中证明了双重封闭效应.
- 识别了具有低协调数量的孤立的贵金属部位.
- 观察到的Rh/Pt·Mo距离比散装金属M·M的距离更短.
- 使用PDF,计算和XAS确定了活跃的集群结构模型.
结论:
- 在POM@MOF结构中的双封闭有效地防止高负载SSC的烧结.
- 能够对以前由于站点负荷较低而受到限制的催化剂进行详细的结构分析.
- 为设计强大且高活性单位催化剂提供了可行的策略.
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