花状沸石咪唑骨架用于高效电还原二氧化碳

Efficient Electrocatalytic Reduction of Carbon Dioxide Using Flower-like Zeolite Imidazole Framework

电还原二氧化碳(CO_(2)RR)是降低CO_(2)含量的有效途径之一,且构筑高活性的电催化剂是该技术的核心。锌基沸石咪唑骨架(ZIF-8)因其制备简单、形貌可控和高CO_(2)吸附性能备受关注。然而,ZIF-8自身CO_(2)还原性能不佳。基于此,该工作通过调控ZIF-8的形貌,得到花状ZIF-8(F-ZIF-8),F-ZIF-8表现出优异的CO_(2)电催化活性,在不加额外导电剂的前提下,生成CO的法拉第效率(FE)达到83%,是传统菱形十二面体ZIF-8(R-ZIF-8)(FE CO=52%)的1.6倍。F-ZIF-8良好的催化活性与其独特的形貌密切相关,实验证明具有分级孔结构的花状形貌不仅有利于CO_(2)分子的吸附和传输,同时可以改善导电性,加速电子转移。此外,该电催化剂还表现出优异的稳定性,可持续稳定还原CO_(2)8 h。这种通过调节ZIF-8的形貌提高其电催化活性的策略,对于开发廉价高效的电催化剂具有重要意义。

Electrocatalytic reduction of carbon dioxide(CO_(2)RR)is one of the effective ways to reduce CO_(2),and the construction of highly active electrocatalysts is the core of this technology.Zinc-based zeolite imidazole framework(ZIF-8)has received widespread attention due to its simple preparation,controlled morphology and high CO_(2) adsorption performance.However,ZIF-8 has poor performance in CO_(2) reduction.Based on this,by regulating the morphology of ZIF-8,the flower-like ZIF-8(F-ZIF-8)has been obtained in this work,and it showed excellent CO_(2) electrocatalytic activity.Without additional conductive agent,the Faraday efficiency(FE)of generated CO reaches 83%,which is 1.6 times than that of the traditional ZIF-8 with the shape of rhombic dodecahedron(R-ZIF-8)(FE CO=52%).The good catalytic activity of F-ZIF-8 is closely related to its unique morphology.The results showed that the flower-like morphology with a hierarchical pore structure not only contributes to the adsorption and transport of CO_(2) molecules,but also enhanced conductivity to accelerate electrons transfer.In addition,this electrocatalyst also exhibited excellent stability,which can continuously and stably reduce CO_(2) for 8 h.This strategy to improve the electrocatalytic activity of ZIF-8 by adjusting its morphology is of great significance for the development of cheap and efficient electrocatalysts.