Three-Dimensional Honeycomb-like Pb-MOF with Multiple Sites for Selective Gas Adsorption and Efficient CO2 Catalytic
Yi-Zhao Guo1, Ming-Shuai Du1, Lin Zhang1
1Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, P. R. China.
None:
One novel honeycomb-like Pb2+-based metal-organic framework [Pb(dtzip)0.5(H2O)]·NMP·2H2O (H4dtzip = 4,6-di(1H-tetrazol-5-yl) isophthalic acid, NMP = N-methyl-2-pyrrolidone) was synthesized through solvothermal reaction of Pb2+ ions with the azolate-carboxylate linker H4dtzip, which displays hexagonal channels with multiple accessible metal centers and N sites. Desolvated framework Pb(dtzip)0.5 shows high porosity and significant adsorption selectivity, achieving effective separation for C2H2/CO2, CO2/CH4, and C2H2/CH4 mixtures, respectively. The exposed Pb2+ Lewis acidic sites in Pb(dtzip)0.5 lead to efficient heterogeneous catalysis for CO2-epoxide cycloaddition, producing cyclic carbonates in high yields. This unusual material demonstrates remarkable substrate versatility, achieving quantitative conversion (99%) for simple substrates such as 1,2-epoxybutane, while maintaining excellent performance (>85% conversion) even with sterically demanding substrates. The role of metal centers and accessible organic sites in selective adsorption and catalytic reactions was deeply investigated through molecular simulations.
