Bagherzadeh Mojtaba, Chegeni Mohsen, Bayrami Arshad, Amini Mojtaba
Chemistry Department, Sharif University of Technology, PO Box, Tehran, 11155-3615, Iran.
Department of Chemistry, Research Center for Development of Advanced Technologies, Tehran, Iran.
Sci Rep. 2024 Jul 31;14(1):17730. doi: 10.1038/s41598-024-68497-2.
This study explored the catalytic performance of two robust zirconium-based metal-organic frameworks (MOFs), MIP-202(Zr) and UiO-66-(COH) in the ring-opening of epoxides using alcohols and amines as nucleophilic reagents. The MOFs were characterized by techniques such as FT-IR, PXRD, FE-SEM, and EDX. Through systematic optimization of key parameters (catalyst amount, time, temperature, solvent), MIP-202(Zr) achieved 99% styrene oxide conversion in 25 min with methanol at room temperature using 5 mg catalyst. In contrast, UiO-66-(COH) required drastically harsher conditions of 120 min, 60 °C, and four times the catalyst loading to reach 98% conversion. A similar trend was observed for ring-opening with aniline -MIP-202(Zr) gave 93% conversion in one hour at room temperature, while UiO-66-(COH) needed two hours at 60 °C for 95% conversion. The superior performance of MIP-202(Zr) likely stems from cooperative Brønsted/Lewis acid sites and higher proton conductivity enabling more efficient epoxide activation. Remarkably, MIP-202(Zr) maintained consistent activity over five recycles in the ring-opening of styrene oxide by methanol and over three recycles in the ring-opening of styrene oxide by aniline. Testing various epoxide substrates and nucleophiles revealed trends in reactivity governed by electronic and steric effects. The results provide useful insights into tuning Zr-MOF-based catalysts and highlight the promise of the cost-effective and sustainable MIP-202(Zr) for diverse epoxide ring-opening reactions on an industrial scale.
本研究探索了两种性能优良的锆基金属有机框架材料（MOF），即MIP-202(Zr)和UiO-66-(COH)，以醇类和胺类作为亲核试剂用于环氧化物开环反应的催化性能。通过傅里叶变换红外光谱（FT-IR）、粉末X射线衍射（PXRD）、场发射扫描电子显微镜（FE-SEM）和能谱分析（EDX）等技术对这些金属有机框架材料进行了表征。通过对关键参数（催化剂量、时间、温度、溶剂）的系统优化，MIP-202(Zr)在室温下使用5毫克催化剂，与甲醇反应25分钟时，苯乙烯氧化物转化率达到99%。相比之下，UiO-66-(COH)则需要120分钟、60°C的更为苛刻的条件以及四倍的催化剂量才能达到98%的转化率。在用苯胺进行开环反应时也观察到了类似的趋势——MIP-202(Zr)在室温下一小时内转化率达到93%，而UiO-66-(COH)在60°C下需要两小时才能达到95%的转化率。MIP-202(Zr)的优异性能可能源于协同的布朗斯特/路易斯酸位点以及更高的质子传导率，从而能够更有效地活化环氧化物。值得注意的是，MIP-202(Zr)在甲醇开环苯乙烯氧化物的反应中经过五次循环仍保持一致的活性，在苯胺开环苯乙烯氧化物的反应中经过三次循环也保持一致的活性。对各种环氧化物底物和亲核试剂的测试揭示了由电子效应和空间效应主导的反应活性趋势。这些结果为调整基于锆的金属有机框架催化剂提供了有用的见解，并突出了成本效益高且可持续的MIP-202(Zr)在工业规模上进行各种环氧化物开环反应的前景。
