在Pt功能化的Hf-UiO-67上,CO2化为甲醇,而不是Zr-UiO-67
Dag Kristian Sannes1, Sri Harsha Pulumati2, Egill Skúlason2
1SMN Centre for Material Science and Nanotechnology, Department of Chemistry, University of Oslo, Oslo N-0315, Norway.
概括
基于哈夫的金属有机框架 (MOFs) 显示出更高的活性,用于从二氧化碳化中可持续生产甲醇,而不是类型. 然而,添加水会导致失活,特别是在Hf-MOF中,影响甲醇和甲的形成速度.
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
- 绿色化学 绿色化学
背景情况:
- 来自二氧化碳 (CO2) 和 (H2) 的可持续甲醇合成对于化石燃料后的化学工业至关重要.
- 用纳米颗粒功能化的金属有机框架 (MOF) 为催化应用提供可调的平台.
- 了解金属节点在MOF基催化剂中的作用对于优化CO2化至关重要.
研究的目的:
- 调查基于Hf和Zr的MOF (UiO-67拓) 的性能,这些MOF与Pt纳米颗粒功能化,用于CO2化.
- 为了比较基于Hf和Zr的催化剂的催化活性,选择性和稳定性.
- 阐明水对催化剂稳定性的影响,并确定潜在的停用机制.
主要方法:
- 基于Hf和Zr的UiO-67 MOFs的合成与 (Pt) 纳米颗粒功能化.
- 在30bar和170-240°C之间的温度下对CO2化进行催化试验.
- 动力学研究,包括明显激活能量的测定,以及在料中含有和不含水的稳定性测试.
主要成果:
- 与基于Zr的类似物 (6.2mol_methanol mol_Pt^-1 h^-1) 相比,基于Hf的催化剂表现出明显更高的甲醇形成率 (14mol_methanol mol_Pt^-1 h^-1).
- 甲醇形成的产品分布和明显的激活能量相似,这表明基于Hf的催化剂的活性位点密度更高.
- 在添加2体积%的水后观察到催化剂失活,主要影响甲醇和甲形成率,Hf-MOFs更容易受到影响.
结论:
- Hf-UiO-67-Pt催化剂在二氧化碳化成甲醇方面表现出卓越的活性.
- 建议将MOF节点的水吸附强度作为影响Hf和Zr基催化剂相对稳定的关键因素.
- 这些发现为设计强大的MOF催化剂提供了洞察力,以实现可持续的化学生产.
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