Hollow Zn−Co Based Zeolitic Imidazole Framework as a Robust Heterogeneous Catalyst for Enhanced CO₂ Chemical Fixation

Abstract

The efficient chemical conversion of carbon dioxide (CO2) into value‐added fine chemicals is an intriguing but challenging route in sustainable chemistry. Herein, a hollow‐structured bimetallic zeolitic imidazole framework composed of Zn and Co as metal centers (H‐ZnCo‐ZIF) has been successfully prepared via a post‐synthetic strategy based on controllable chemical‐etching of the preformed solid ZnCo‐ZIF in tannic acid. The creation of hollow cavities inside each monocrystalline ZIFs could be achieved without destroying the intrinsic frameworks, as characterized by field‐emission scanning electron microscopy, transmission electron microscopy, and X‐ray diffraction technologies. The as‐synthesized H‐ZnCo‐ZIF exhibited remarkable catalytic activity in the cycloaddition of CO2 with epoxides to the corresponding cyclic carbonates, outperforming the solid ZnCo‐ZIF analogue due to the improved mass transfer originating from the hollow structure. More importantly, due to stabilization of metal centers in the ZIF framework by the tannic acid shell, H‐ZnCo‐ZIF exhibited good recyclability, and no activity loss could be observed in six runs. The present study provides a simple and effective strategy to enhance the catalytic performance of ZIFs by creating a hollow structure via chemical etching.

Precisely Engineering Architectures of Co/C Sub‐Microreactors for Selective Syngas Conversion

“…Comparing with ZIF‐67, TG curves of the etched samples present two weight losses below 500 °C, which can be attributed to the desorption and decomposition of TA based on previously reported reference. [ 16 ] Without regard to TA weight loss, TA‐YS and TA‐Box possess a decomposition temperature similar to that of ZIF‐67, meaning that the etching causes almost no change to the decomposition temperature of framework.…”

Removal of carbon dioxide using zeolitic imidazolate frameworks: Adsorption and conversion via catalysis

“…[ 350 ] Cocatalysts such as n ‐Bu 4 NBr (TBAB), n ‐Pr 4 NBr, n ‐Pr 4 NBr, and Me 4 NBr showed a carbonate yield of 91%, 68%, 33%, and 6%, respectively, using hollow‐structured Zn–Co‐based ZIF. [ 240 ] The catalytic performance of these cocatalysts can be ordered in the sequence of n Bu 4 N + > n ‐Pr 4 N + > Et 4 N + > Me 4 N + . The high performance of TBAB is due to the low interaction between n Bu 4 N + and Br − .…”

“…[231][232][233] Thus, this reaction requires a catalyst (Table 3). There are several ZIF materials including ZIF-8, [234] ZIF-23, [254] ZIF-90, [235,255,256] ZIF-95, [236] ZIF-67, [237,238] bimetallic (Zn,Co) ZIF-67, [239,240,257] Co/ ZIF-8, [241] Fe/ZIF-8, [242] and ZIF-68. [243] Bimetallic (Co,Zn)-ZIF-derived magnetic catalyst was also reported (Table 3).…”

A Review on Removal of Carbon Dioxide (CO2) using Zeolitic Imidazolate Frameworks: Adsorption and Conversion via Catalysis

“…There are several ZIFs materials including ZIF-8 [234] , ZIF-23 [235] , ZIF-90 [236][237][238] , ZIF-95 [239] , ZIF-67 [240,241] , bimetallic (Zn, Co) ZIF-67 [242][243][244] , Co/ZIF-8 [245] , Fe/ZIF-8 [246] , and ZIF-68 [247] .…”

“…The catalytic performance can be improved via the addition of a co-catalyst, e.g., TBAB [279] , or gold (Au) [349] . Co-catalysts such as n-Bu4NBr (TBAB), n-Pr4NBr, n-Pr4NBr, Me4NBr showed a carbonate yields of 91%, 68%, 33%, and 6%, respectively, using hollow-structured Zn−Co based ZIF [244] . The catalytic performance of these co-catalysts can be ordered in the sequence of nBu4N + >n-Pr4N + >Et4N + >Me4N + .…”