Efficient and Selective Methane Borylation Through Pore Size Tuning of Hybrid Porous Organic‐Polymer‐Based Iridium Catalysts. Issue 31 (27th June 2019)

• Record Type: Journal Article
• Authors: Chen, Qi; Dong, Anwang; Wang, Dongxu; Qiu, Lu; Ma, Chunxin; Yuan, Yihui; Zhao, Yunpeng; Jia, Na; Guo, Zhanhu; Wang, Ning
• Is Part Of: Angewandte Chemie international edition. Volume 58:Issue 31(2019)
• Page Start: 10671
• Page End: 10676
• Publication Date: 2019-06-27
• Subjects: direct methane conversion -- heterogeneous catalysts -- hybrid composite -- iridium complexes -- porous organic polymers; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201906350
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: As a new energy source that could replace petroleum, the global reserves of methane hydrate (combustible ice) are estimated to be approximately 20 000 trillion cubic meters. A large amount of methane hydrate has been found under the seabed, but the transportation and storage of methane gas far from coastlines are technically unfeasible and expensive. The direct conversion of methane into value‐added chemicals and liquid fuels is highly desirable but remains challenging. Herein, we prepare a series of iridium complexes based on porous polycarbazoles with high specific areas and good thermochemical stabilities. Through structure tuning we optimized their catalytic activities for the selective monoborylation of methane. One of these catalysts (CAL‐3‐Ir) can produce methyl boronic acid pinacol ester (CH3 Bpin) in 29 % yield in 9 h with a turnover frequency (TOF) of approximately 14 h −1 . Because its pore sizes favor monoborylated products, it has a high chemoselectivity for monoborylation (CH3 Bpin:CH2 (Bpin)2 =16:1). Abstract : Pore patrol : A series of heterogenous catalysts based on iridium complexes bound inside porous polycarbazoles was prepared for the selective monoborylation of methane. Catalysts with high efficiency and good chemoselectivity can be developed through tuning the pore size distribution of the porous polycarbazole.