近年来, 限域空间中粒子独特的物理和化学特性引起了广泛的关注，空间限域

近年来, 限域空间中粒子独特的物理和化学特性引起了广泛的关注，空间限域效应能够调节催化剂粒子大小，在反应过程中限制粒子团聚，有效维持反应活性和稳定性。通过空间择形、选择吸附及脱附等影响催化反应中反应物和产物分子在狭小空间内活性位周围的扩散行为，从而影响反应活性和目标产物选择性，产生明显的空间富集效应。限域空间内缺电子的特殊电子结构，影响组装于空间内催化剂的电子性质，起到有效调变反应活性和产物选择性的作用。本文以限域空间中羟基的酸性特征和催化性能为出发点,系统介绍体系尺寸变化导致羟基酸性和催化特性调控的实验和理论研究结果, 认识如何根据催化反应特性调变催化剂结构和电子特性，进而帮助提高催化过程的效率，实现对反应性能的调控。<br>碳纳米管被发现至今已有近30年历史。碳纳米管与其他碳材料最大的区别在于其准一维的纳米级管腔结构，将金属纳米颗粒组装入纳米孔道可得到由炭质材料构成的纳米反应器。这样的组装结构具有诸多优点，如限域其中的金属纳米粒子在反应过程中不易长大；一维孔道对某种反应物或产物分子具有吸附富集特性；更重要的是，石墨烯片以一定曲率卷曲形成碳纳米管的过程中，原先在石墨平面上下呈对称结构的电子云发生变化，这种变化调控了限域其中金属催化剂的电子性质。碳纳米管的纳米级管腔不仅为纳米催化剂和催化反应提供特定的几何限域环境，而且其独特的电子结构也对管腔内外催化剂的电子转移特性具有调制作用，使限域在碳纳米管管腔内的纳米粒子显示出独特的催化行为。<br>碳纳米管的限域效应主要表现在：一是对催化剂而言，限制管腔内纳米粒子的凝聚和生长，管腔内缺电子环境调制催化剂粒子的电子特征；二是对反应物而言，管内外吸附能力不同造成反应物局域浓度的变化；三是对反应过程而言，改变催化反应活化能，调变反应通道；四是对反应 产物而言，改变产物分子在管腔内的扩散动力学。[1]

近年来, 限域空间中粒子独特的物理和化学特性引起了广泛的关注，空间限域效应能够调节催化剂粒子大小，在反应过程中限制粒子团聚，有效维持反应活性和稳定性。 通过空间择形、选择吸附及脱附等影响催化反应中反应物和产物分子在狭小空间内活性位周围的扩散行为，从而影响反应活性和目标产物选择性，产生明显的空间富集效应。 限域空间内缺电子的特殊电子结构，影响组装于空间内催化剂的电子性质，起到有效调变反应活性和产物选择性的作用。 本文以限域空间中羟基的酸性特征和催化性能为出发点,系统介绍体系尺寸变化导致羟基酸性和催化特性调控的实验和理论研究结果, 认识如何根据催化反应特性调变催化剂结构和电子特性，进而帮助提高催化过程的效率，实现对反应性能的调控。<br>碳纳米管被发现至今已有近30年历史。 碳纳米管与其他碳材料最大的区别在于其准一维的纳米级管腔结构，将金属纳米颗粒组装入纳米孔道可得到由炭质材料构成的纳米反应器。 这样的组装结构具有诸多优点，如限域其中的金属纳米粒子在反应过程中不易长大；一维孔道对某种反应物或产物分子具有吸附富集特性；更重要的是，石墨烯片以一定曲率卷曲形成碳纳米管的过程中，原先在石墨平面上下呈对称结构的电子云发生变化，这种变化调控了限域其中金属催化剂的电子性质。 碳纳米管的纳米级管腔不仅为纳米催化剂和催化反应提供特定的几何限域环境，而且其独特的电子结构也对管腔内外催化剂的电子转移特性具有调制作用，使限域在碳纳米管管腔内的纳米粒子显示出独特的催化行为。<br>碳纳米管的限域效应主要表现在：一是对催化剂而言，限制管腔内纳米粒子的凝聚和生长，管腔内缺电子环境调制催化剂粒子的电子特征；二是对反应物而言，管内外吸附能力不同造成反应物局域浓度的变化；三是对反应过程而言，改变催化反应活化能，调变反应通道；四是对反应 产物而言，改变产物分子在管腔内的扩散动力学。 [1]

In recent years, the unique physical and chemical properties of the particles in the confined space have attracted extensive attention. The confined space effect can adjust the size of catalyst particles, limit the agglomeration of particles in the reaction process, and effectively maintain the activity and stability of the reaction. The diffusion behavior of reactants and product molecules around the active sites in a narrow space is affected by space shape selection, selective adsorption and desorption, so as to affect the reaction activity and the selectivity of target products and produce obvious space enrichment effect. The special electronic structure in the confined space affects the electronic properties of the catalysts assembled in the confined space, and plays an effective role in adjusting the reaction activity and product selectivity. Based on the acidity and catalytic properties of hydroxyl in the confined space, this paper systematically introduces the experimental and theoretical results of the regulation of the acidity and catalytic properties of hydroxyl caused by the size change of the system, and knows how to adjust the structure and electronic properties of the catalyst according to the catalytic reaction characteristics, so as to help improve the efficiency of the catalytic process and realize the regulation of the reaction performance.<br>Carbon nanotubes have been found for nearly 30 years. The biggest difference between carbon nanotubes and other carbon materials lies in their quasi one-dimensional nanoscale cavity structure. The nano reactor made of carbon materials can be obtained by assembling metal nanoparticles into the nano channels. This kind of assembly structure has many advantages, for example, the metal nanoparticles in the confinement are not easy to grow up in the reaction process; the one-dimensional channel has the adsorption and enrichment characteristics for a certain reactant or product molecule; more importantly, in the process of the graphene sheet curling to form carbon nanotubes with a certain curvature, the electron cloud with symmetrical structure on the graphite plane originally changes, which changes The electronic properties of the metal catalysts in the confinement were controlled. The nanoscale cavity of carbon nanotubes not only provides a specific geometric confinement environment for nano catalysts and catalytic reactions, but also modulates the electron transfer characteristics of catalysts inside and outside the cavity with its unique electronic structure, which makes the nanoparticles within the confinement of carbon nanotubes show a unique catalytic behavior.<br>The confinement effect of carbon nanotubes is mainly manifested in: first, for catalyst, confine the agglomeration and growth of nanoparticles in the cavity, and the lack of electronic environment in the cavity modulates the electronic characteristics of catalyst particles; second, for reactants, different adsorption capacities inside and outside the tube cause changes in the local concentration of reactants; third, for reaction process, change the activation energy of catalytic reaction and adjust the reaction The fourth is to change the diffusion kinetics of the product molecules in the lumen. [1]<br>