负载型催化剂的制备与催化机理研究
摘要
负载型催化剂在化工、能源和环境领域具有重要应用价值，其活性组分与载体之间的相互作用对催化性能起着关键作用。本研究旨在通过优化制备工艺，深入探究负载型催化剂的结构特性及其催化机理。以贵金属Pt为活性组分，采用浸渍法制备了不同载体（TiO2、SiO2、Al2O3）负载的Pt基催化剂，并系统考察了焙烧温度、浸渍时间等参数对催化剂结构和性能的影响。利用XRD、TEM、H2-TPR等表征手段分析了催化剂的微观结构，结果表明Pt纳米颗粒在TiO2载体上分散性最佳，且粒径最小。在丙烯选择性加氢反应中，Pt/TiO2表现出优异的催化活性和稳定性，转化率可达95%以上，选择性高达87%，远优于其他两种载体。通过原位红外光谱和DFT理论计算揭示了反应过程中活性物种的生成及转化机制，发现TiO2载体能够有效促进氢气解离吸附，增强Pt与底物分子之间的协同作用。该研究不仅为负载型催化剂的设计提供了理论依据，还为其工业应用奠定了坚实基础，特别是为开发高效稳定的丙烯选择性加氢催化剂开辟了新途径。
关键词：负载型催化剂；Pt/TiO2；丙烯选择性加氢
Abstract
Supported catalysts play a crucial role in the fields of chemical industry, energy, and environmental protection, where the interaction between active components and supports significantly influences catalytic performance. This study aims to optimize preparation processes and thoroughly investigate the structural characteristics and catalytic mechanisms of supported catalysts. Using platinum (Pt) as the active component, Pt-based catalysts supported on different carriers (TiO2, SiO2, Al2O3) were prepared via impregnation method, systematically examining the effects of calcination temperature and impregnation time on catalyst structure and performance. Characterization techniques including XRD, TEM, and H2-TPR were employed to analyze the microstructure of the catalysts, revealing that Pt nanoparticles exhibited optimal dispersion and smallest particle size on TiO2 supports. In selective hydrogenation of propylene, Pt/TiO2 demonstrated superior catalytic activity and stability with conversion rates exceeding 95% and selectivity as high as 87%, significantly outperforming the other two supports. In-situ infrared spectroscopy and DFT theoretical calculations elucidated the generation and transformation mechanisms of active species during the reaction, indicating that TiO2 supports effectively promote hydrogen dissociative adsorption and enhance the synergistic effect between Pt and substrate molecules. This research not only provides theoretical basis for the design of supported catalysts but also lays a solid foundation for their industrial application, particularly in developing highly efficient and stable catalysts for selective hydrogenation of propylene.
Keywords：Supported Catalyst; Pt/TiO2; Propylene Selective Hydrogenation
目 录
摘要 I
Abstract II
一、绪论 1
(一) 负载型催化剂研究背景与意义 1
(二) 国内外研究现状综述 1
(三) 本文研究方法与技术路线 2
二、负载型催化剂的制备工艺 2
(一) 催化剂载体的选择与特性 2
(二) 活性组分的负载技术 3
(三) 制备参数对性能的影响 3
三、负载型催化剂的表征分析 4
(一) 物理化学性质表征 4
(二) 表面结构与形貌分析 5
(三) 组成与价态变化研究 5
四、负载型催化剂的催化机理 6
(一) 反应动力学研究 6
(二) 活性位点的识别与作用 7
(三) 催化反应路径解析 7
结 论 9
参考文献 10
摘要
负载型催化剂在化工、能源和环境领域具有重要应用价值，其活性组分与载体之间的相互作用对催化性能起着关键作用。本研究旨在通过优化制备工艺，深入探究负载型催化剂的结构特性及其催化机理。以贵金属Pt为活性组分，采用浸渍法制备了不同载体（TiO2、SiO2、Al2O3）负载的Pt基催化剂，并系统考察了焙烧温度、浸渍时间等参数对催化剂结构和性能的影响。利用XRD、TEM、H2-TPR等表征手段分析了催化剂的微观结构，结果表明Pt纳米颗粒在TiO2载体上分散性最佳，且粒径最小。在丙烯选择性加氢反应中，Pt/TiO2表现出优异的催化活性和稳定性，转化率可达95%以上，选择性高达87%，远优于其他两种载体。通过原位红外光谱和DFT理论计算揭示了反应过程中活性物种的生成及转化机制，发现TiO2载体能够有效促进氢气解离吸附，增强Pt与底物分子之间的协同作用。该研究不仅为负载型催化剂的设计提供了理论依据，还为其工业应用奠定了坚实基础，特别是为开发高效稳定的丙烯选择性加氢催化剂开辟了新途径。
关键词：负载型催化剂；Pt/TiO2；丙烯选择性加氢
Abstract
Supported catalysts play a crucial role in the fields of chemical industry, energy, and environmental protection, where the interaction between active components and supports significantly influences catalytic performance. This study aims to optimize preparation processes and thoroughly investigate the structural characteristics and catalytic mechanisms of supported catalysts. Using platinum (Pt) as the active component, Pt-based catalysts supported on different carriers (TiO2, SiO2, Al2O3) were prepared via impregnation method, systematically examining the effects of calcination temperature and impregnation time on catalyst structure and performance. Characterization techniques including XRD, TEM, and H2-TPR were employed to analyze the microstructure of the catalysts, revealing that Pt nanoparticles exhibited optimal dispersion and smallest particle size on TiO2 supports. In selective hydrogenation of propylene, Pt/TiO2 demonstrated superior catalytic activity and stability with conversion rates exceeding 95% and selectivity as high as 87%, significantly outperforming the other two supports. In-situ infrared spectroscopy and DFT theoretical calculations elucidated the generation and transformation mechanisms of active species during the reaction, indicating that TiO2 supports effectively promote hydrogen dissociative adsorption and enhance the synergistic effect between Pt and substrate molecules. This research not only provides theoretical basis for the design of supported catalysts but also lays a solid foundation for their industrial application, particularly in developing highly efficient and stable catalysts for selective hydrogenation of propylene.
Keywords：Supported Catalyst; Pt/TiO2; Propylene Selective Hydrogenation
目 录
摘要 I
Abstract II
一、绪论 1
(一) 负载型催化剂研究背景与意义 1
(二) 国内外研究现状综述 1
(三) 本文研究方法与技术路线 2
二、负载型催化剂的制备工艺 2
(一) 催化剂载体的选择与特性 2
(二) 活性组分的负载技术 3
(三) 制备参数对性能的影响 3
三、负载型催化剂的表征分析 4
(一) 物理化学性质表征 4
(二) 表面结构与形貌分析 5
(三) 组成与价态变化研究 5
四、负载型催化剂的催化机理 6
(一) 反应动力学研究 6
(二) 活性位点的识别与作用 7
(三) 催化反应路径解析 7
结 论 9
参考文献 10
