卟啉基自组装膜同步光催化芳香醇选择性氧化和过氧化氢生成的性能研究

Porphyrin-Based Self-Assembled Film Photo-Catalysts with Simultaneous Selective Oxidation of Aromatic Alcohols and H2O2 Generation

摘要:

在温和的条件下实现对芳香醇选择性氧化是一个重大挑战。以中-四（4-羧基苯基）卟吩或中-四（4-羧基苯基）钴卟吩为有机配体、Zn₂⁴⁺为无机金属节点、4,4’-联吡啶为连接体，通过分步方式制备自组装膜（分别命名为TCPP和TCPP-CoTCPP）。利用紫外可见吸收光谱和原子力显微镜对上述自组装膜的制备过程及组装结果进行表征。结果表明：TCPP-CoTCPP中光生电子-空穴对的分离效率和界面电荷迁移率较TCPP高，室温有氧条件下该自组装膜表现出良好的同步光催化芳香醇选择性氧化和过氧化氢生成性能；在优化的反应条件下，TCPP的过氧化氢产量为47.23 mmol，芳香醇氧化为芳香醛的选择性为48.4%；通过对自组装膜的有机配体调控，TCPP-CoTCPP过氧化氢产量提高到68.73 mmol，芳香醇氧化为芳香醛的选择性提升到84.2%。

Abstract:

Achieving selective oxidation of aromatic alcohols under mild conditions is a major challenge. In this work， self-assembled films were prepared by a step-by-step approach， using meso-tetra（4-carboxyphenyl） porphine or meso-tetra（4-carboxyphenyl） porphine cobalt（II） ligands， zinc inorganic metal node， and 4，4’-bipyridine linker， named TCPP and TCPP-CoTCPP， respectively. The preparation process and assembly results of the above self-assembled films were characterized using UV-vis spectroscopy and atomic force microscopy. The results reveal that TCPP-CoTCPP demonstrated higher photo-generated electron-hole （e-h） separation and charge transfer efficiency than TCPP. Under aerobic conditions at room temperature， the TCPP-CoTCPP exhibited excellent simultaneous photocatalytic selective oxidation of aromatic alcohol and H₂O₂ generation. Under the optimized reaction conditions， the H₂O₂ evolution of TCPP was 47.23 mmol， and the selectivity of oxidation of aromatic alcohols to aromatic aldehydes was 48.4%. By regulating the organic ligand of the self-assembled membrane， the H₂O₂ evolution of TCPP-CoTCPP was increased to 68.73 mmol， and the selectivity of oxidation of aromatic alcohol to aromatic aldehyde was improved to 84.2%.