从Pd-Ag合金上获得超高选择性生产
Mustafa Karatok1, Hio Tong Ngan2, Xiwen Jia1
1Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States.
Journal of the American Chemical Society
|February 27, 2023
概括
银合金催化剂可以从酸中生产无二氧化碳的. 通过修饰的特定表面银域是选择性生成的关键,增强了燃料电池应用.
科学领域:
- 催化科学
- 材料科学
- 表面化学
背景情况:
- -银 (Pd-Ag) 合金有望从酸中生产无碳气,这对燃料电池技术至关重要.
- 了解Pd-Ag合金中酸分解选择性的精确结构因素仍然是一个挑战.
研究的目的:
- 研究不同原子配置的Pd-Ag合金中的酸分解途径.
- 确定促进 (H2) 生产高选择性的特定合金结构.
主要方法:
- 在Pd-Ag单晶上生成表面合金.
- 使用红外反射吸收光谱 (IRAS),X射线光电子光谱 (XPS) 和密度函数理论 (DFT) 的表征.
- 使用温度编程反应光谱 (TPRS) 和DFT分析反应途径.
主要成果:
- 通过邻近的Pd原子观察到Ag原子的电子变化,与Pd邻居的数量相关.
- 电子修饰的Ag域促进了选择性酸脱路径.
- 表面Pd原子虽然不太容易中毒,但不会增强选择性,并且可以产生像CO这样的不良副产品.
结论:
- 被地下Pd影响的表面Ag域被确定为选择性酸分解的主要活性位点.
- 表面的 Pd 原子对无 CO 的 H2 生产有负面影响.
- 定制Pd-Ag合金结构为燃料电池提供了优化无碳生成的途径.
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