通过对Ni-CeO2-ZrO2/Al2O3催化剂的原子层沉积,提高了甲干改的选择性和稳定性
Jonathan Lucas1, Nirenjan Shenoy Padmanabha Naveen2, Michael J Janik2
1Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, United States.
概括
催化剂上的超薄氧化覆盖层显著提高了甲干改造 (DRM) 的活性和稳定性. 这种涂层优化了与一氧化碳的比率,防止在恶劣条件下触媒失活.
科学领域:
- 催化剂是一种催化剂.
- 材料科学 材料科学 材料科学
- 化学工程是化学工程的重要组成部分.
背景情况:
- (Ni) 催化剂是高贵金属的有希望的替代品,用于甲干重制 (DRM).
- 在DRM条件下,Ni催化剂遭受快速停用.
- 像Ceria-Zirconia-Alumina (CZA) 这样的反氧活性支物改善了Ni催化剂的性能,但可以促进逆水气转移 (RWGS) 反应.
研究的目的:
- 为了研究超薄氧化 (Al2O3) 覆盖层对DRM的Ni/CZA催化剂的影响.
- 评估Al2O3覆盖层对催化剂活性,稳定性和产品选择性的影响 (H2/CO比).
- 为了确定最佳的Al2O3覆盖层厚度,以提高DRM性能.
主要方法:
- 原子层沉积 (ALD) 用于将超薄的Al2O3覆盖层应用到Ni/CZA催化剂上.
- 催化剂性能在低转换时进行选,并在反应堆中高转换时得到确认.
- 采用了表征技术来分析反应前后的催化剂的结构和组成.
主要成果:
- Al2O3 ALD外层改善了DRM活动,并降低了焦化速率.
- 与高转化率的未涂层催化剂相比,涂层催化剂的H2/CO比率 (∼1) 显著更高.
- 对于涂层样本,即使经过长时间的操作,也没有观察到催化剂的失活.
- 在名义Al2O3覆盖层厚度为0.5nm时,可以达到最佳性能.
结论:
- 超薄的Al2O3覆盖层有效地稳定了Ni/CZA催化剂,用于甲的干式重制.
- ALD是一种适合精确控制上层厚度以提高催化剂性能的方法.
- 经过优化,具有Al2O3覆盖层的Ni/CZA催化剂为甲转化提供了稳定和选择性的途径.
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