用非热等离子体访问的振动活性表面物种的观测和描述
Garam Lee1, Chang Yan1, William F Schneider1,2
1Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States.
ACS applied materials & interfaces
|January 19, 2024
概括
非热等离子体 (NTP) 在金属上激活 (N2),从而产生新的振动特征. 这一特征很可能是三原子NCO物种,而不是化学吸收的N2,由于微量杂质.
科学领域:
- 表面科学是一门学科.
- 等离子体化学
- 材料科学 材料科学 材料科学
背景情况:
- 像Ni,Pd,Cu,Ag和Au这样的金属在催化过程中至关重要.
- 非热等离子体 (NTP) 激活N2可以创建独特的表面物种.
- 在等离子体环境中解释表面物种是具有挑战性的.
研究的目的:
- 为了研究在暴露于NTP激活N2.2的金属上观察到的一种新奇的振动特征.
- 为了确定负责这种特征的化学物种.
- 了解杂质在等离子体表面相互作用中的作用.
主要方法:
- 偏振调制红外反射吸收光谱 (PM-IRAS) 用于振动分析.
- 温度依赖的实验和顺序剂量用于表面特征.
- X射线光电子光谱 (XPS) 和同位素标记用于元素和结构分析.
- 密度函数理论 (DFT) 计算用于理论验证.
主要成果:
- 在暴露于NTP激活N2的金属上观察到接近2200cm-1的明显的振动特征,在非等离子条件下缺席.
- 实验和计算证据强烈表明该特征起源于三原子NCO物种.
- 来自气的微量杂质 (C,O) 被确定为NCO形成的可能来源.
结论:
- 观察到的特征归因于NCO,而不是化学吸收的N2,挑战了以前的任务.
- 通过NTP,可以形成通过热方法无法进入的表面物种.
- 即使是微量杂质也可以显著影响等离子体驱动的表面化学的解释.
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