NH2-UIO-66负载RuCuMo纳米催化剂的制备及其催化产氢

采用锆盐和2-氨基对苯二甲酸以溶剂热法成功制备了氨基化的金属有机骨架化合物NH₂-UIO-66, 并利用浸渍还原法成功负载RuCuMo纳米粒子, 制备了RuCuMo@NH₂-UIO-66催化剂。通过X射线粉末衍射仪(XRD)、透射电子显微镜(TEM)、场发射扫描电镜(SEM)等技术对NH₂-UIO-66、RuCuMo@NH₂-UIO-66的结构、形貌、组成和比表面积进行了表征, 并对载体、多金属负载型催化剂以及无载体的RuCuMo纳米粒子的产氢性能进行了分析。结果显示, Ru₁Cu₂Mo_0.5@NH₂-UIO-66催化剂的催化活性最高, 引入Cu和Mo能显著增强Ru对氨硼烷水解产氢的催化活性。这主要归因于RuCuMo纳米粒子之间强的协同作用, RuCuMo纳米粒子与载体NH₂-UIO-66间的双功能效应, 以及MOFs上氨基的锚锭作用, 可以阻止金属粒子的团聚, 促进超细粒子的形成。催化反应的活化能(E_a)为30.1 kJ?mol ^-1, 转化频率(TOF)为180.83 $text{mo}{{text{l}}_{{{text{H}}_{2}}}}cdot text{mol}_{text{Ru}}^{-1}cdot {{min }^{-1}}$, 非贵金属Cu和Mo的引入为催化活性的提高和工业应用提供了重要的研究价值。

Preparation and Dehydrogenation Property of NH2-UIO-66 Supported RuCuMo Nanocatalyst

Amine-functionalize metal organic framework (NH₂-UIO-66) was successfully synthesized by solvothermal method with zirconium salt and 2-aminoterephtalic acid. Tri-metallic RuCuMo nanoparticles (NPs) were immobilized by a facile impregnation-reduction method to prepare RuCuMo@NH₂-UIO-66 catalysts. The structure, morphology, composition and specific surface area of the above catalysts were characterized. Ru₁Cu₂Mo_0.5@NH₂-UIO-66 catalyst exhibits the highest catalytic activity comparing with Ru, RuCu and CuMo counterparts as well as pure tri-metallic RuCuMo NPs in hydrolytic dehydrogenation of ammonia borane at room temperature, and the correspoding activation energy (E_a) and turnover frequency values (TOF) are 30.1 kJ?mol ^-1 and 180.83 mol H₂ min ^-1(mol Ru) ^-1, respectively. Addition of Cu and Mo can significantly enhance the catalytic activity of Ru counterparts, owing to the synergistic effect among Ru, Cu and Mo atoms, bi-functional effect generated between RuCuMo NPs and NH₂-UIO-66 support, and the amine as anchoring groups in the NH₂-UIO-66 framework, which facilitate the formation and stabilization of ultra-small RuCuMo NPs by preventing their aggregation. The addition of non-noble metals Cu and Mo provides an important approach for the improvement of catalytic activity and industrial application.