scholarly journals Remedy for Collapse of ZIF Derived Carbon: Micro-Pore Filled Synthesis to Improve ORR Catalytic Property

Author(s):  
Xingxing Wu ◽  
Songwei Zhang ◽  
Jiaojiao Gao ◽  
Xiaopeng Liu ◽  
Qunhui Yuan ◽  
...  

Abstract Zeolitic imidazolate framework (ZIF) derived carbons deliver outstanding performance as oxygen reduction reaction (ORR) catalysts. However, their electrocatalytic activities are limited due to unavoidable collapse of ZIFs upon pyrolysis, which results in degradation of porosity, sintering of metals and loss of active sites. In this work, a micro-pore filling strategy was employed to strength the architecture of ZIF by using size matched cyanamide molecules as fillers. The cyanamide with high nitrogen content shows a triple effect in stabilizing the carbonaceous skeleton, preserving of metal containing active sites and improving the conductivity of matrix. Therefore, the as-prepared Fe, Co co-doped ZIF derived carbon (FeCo@NC-N) delivers a significantly improved electrochemical activity for ORR than its unfilled counterpart, with half-wave potential upshifted by 30 mV (0.84 V vs. RHE). Besides, a promoted power density of home-assembled zinc-air battery is obtained when FeCo@NC-N is applied as cathode catalyst. This work demonstrates a reliable approach to mitigate framework collapse of metal organic framework (MOF), thus may open a new way for fabrication of MOF based catalysts with increased loading of pores and active sites.

Author(s):  
Danni Zhou ◽  
Xinyuan Li ◽  
Huishan Shang ◽  
Fengjuan Qin ◽  
Wenxing Chen

Metal-organic framework (MOF) derived single-atom catalysts (SACs), featured unique active sites and adjustable topological structures, exhibit high electrocatalytic performance on carbon dioxide reduction reactions (CO2RR). By modulating elements and atomic...


2021 ◽  
Author(s):  
Meng Ge ◽  
Yanzhi Wang ◽  
Francesco Carraro ◽  
Weibin Liang ◽  
Morteza Roostaeinia ◽  
...  

<p>Metal-organic frameworks (MOFs) are known for their versatile combination of inorganic building units and organic linkers, which offers immense opportunities in a wide range of applications. However, many MOFs are typically synthesized as multiphasic polycrystalline powders, which are challenging for studies by X-ray diffraction. Therefore, developing new structural characterization techniques is highly desired in order to accelerate discoveries of new materials. Here, we report a high-throughput approach for structural analysis of MOF nano- and sub-microcrystals by three-dimensional electron diffraction (3DED). A new zeolitic-imidazolate framework (ZIF), denoted ZIF-EC1<a>, </a>was first discovered in a trace amount during the study of a known ZIF-CO<sub>3</sub>-1 material by 3DED. The structures of both ZIFs were solved and refined using 3DED data. ZIF-EC1 has a dense 3D framework structure, which is built by linking mono- and bi-nuclear Zn clusters and 2-methylimidazolates (mIm<sup>-</sup>). With a composition of Zn<sub>3</sub>(mIm)<sub>5</sub>(OH), ZIF-EC1 exhibits high N and Zn densities. We show that the N-doped carbon material derived from ZIF-EC1 is a promising electrocatalysis for oxygen reduction reaction (ORR). The discovery of this new MOF and its conversion to an efficient electrocatalyst highlights the power of 3DED in developing new materials and their applications. </p>


2020 ◽  
Vol 8 (19) ◽  
pp. 9536-9544 ◽  
Author(s):  
Chaochao Zhang ◽  
Hao Yang ◽  
Dan Zhong ◽  
Yang Xu ◽  
Yanzhi Wang ◽  
...  

A yolk–shell structured metal–organic framework (MOF) with encapsulated 5,10,15,20-tetraphenylporphyrinatoiron (FeTPP) in a zeolitic imidazolate framework (ZIF)-L-ZIF-8 is reported.


2021 ◽  
Author(s):  
Meng Ge ◽  
Yanzhi Wang ◽  
Francesco Carraro ◽  
Weibin Liang ◽  
Morteza Roostaeinia ◽  
...  

<p>Metal-organic frameworks (MOFs) are known for their versatile combination of inorganic building units and organic linkers, which offers immense opportunities in a wide range of applications. However, many MOFs are typically synthesized as multiphasic polycrystalline powders, which are challenging for studies by X-ray diffraction. Therefore, developing new structural characterization techniques is highly desired in order to accelerate discoveries of new materials. Here, we report a high-throughput approach for structural analysis of MOF nano- and sub-microcrystals by three-dimensional electron diffraction (3DED). A new zeolitic-imidazolate framework (ZIF), denoted ZIF-EC1<a>, </a>was first discovered in a trace amount during the study of a known ZIF-CO<sub>3</sub>-1 material by 3DED. The structures of both ZIFs were solved and refined using 3DED data. ZIF-EC1 has a dense 3D framework structure, which is built by linking mono- and bi-nuclear Zn clusters and 2-methylimidazolates (mIm<sup>-</sup>). With a composition of Zn<sub>3</sub>(mIm)<sub>5</sub>(OH), ZIF-EC1 exhibits high N and Zn densities. We show that the N-doped carbon material derived from ZIF-EC1 is a promising electrocatalysis for oxygen reduction reaction (ORR). The discovery of this new MOF and its conversion to an efficient electrocatalyst highlights the power of 3DED in developing new materials and their applications. </p>


2021 ◽  
Author(s):  
Meng Ge ◽  
Yanzhi Wang ◽  
Francesco Carraro ◽  
Weibin Liang ◽  
Morteza Roostaeinia ◽  
...  

<p>Metal-organic frameworks (MOFs) are known for their versatile combination of inorganic building units and organic linkers, which offers immense opportunities in a wide range of applications. However, many MOFs are typically synthesized as multiphasic polycrystalline powders, which are challenging for studies by X-ray diffraction. Therefore, developing new structural characterization techniques is highly desired in order to accelerate discoveries of new materials. Here, we report a high-throughput approach for structural analysis of MOF nano- and sub-microcrystals by three-dimensional electron diffraction (3DED). A new zeolitic-imidazolate framework (ZIF), denoted ZIF-EC1<a>, </a>was first discovered in a trace amount during the study of a known ZIF-CO<sub>3</sub>-1 material by 3DED. The structures of both ZIFs were solved and refined using 3DED data. ZIF-EC1 has a dense 3D framework structure, which is built by linking mono- and bi-nuclear Zn clusters and 2-methylimidazolates (mIm<sup>-</sup>). With a composition of Zn<sub>3</sub>(mIm)<sub>5</sub>(OH), ZIF-EC1 exhibits high N and Zn densities. We show that the N-doped carbon material derived from ZIF-EC1 is a promising electrocatalysis for oxygen reduction reaction (ORR). The discovery of this new MOF and its conversion to an efficient electrocatalyst highlights the power of 3DED in developing new materials and their applications. </p>


2019 ◽  
Vol 7 (3) ◽  
pp. 609-619 ◽  
Author(s):  
Wanfeng Xiong ◽  
Hongfang Li ◽  
Hanhui You ◽  
Minna Cao ◽  
Rong Cao

Abstract Applying metal organic frameworks (MOFs) in electrochemical systems is a currently emerging field owing to the rich metal nodes and highly specific surface area of MOFs. However, the problems for MOFs that need to be solved urgently are poor electrical conductivity and low ion transport. Here we present a facile in situ growth method for the rational synthesis of MOFs@hollow mesoporous carbon spheres (HMCS) yolk–shell-structured hybrid material for the first time. The size of the encapsulated Zeolitic Imidazolate Framework-67 (ZIF-67) is well controlled to 100 nm due to the spatial confinement effect of HMCS, and the electrical conductivity of ZIF-67 is also increased significantly. The ZIF@HMCS-25% hybrid material obtained exhibits a highly efficient oxygen reduction reaction activity with 0.823 V (vs. reversible hydrogen electrode) half-wave potential and an even higher kinetic current density (JK = 13.8 mA cm−2) than commercial Pt/C. ZIF@HMCS-25% also displays excellent oxygen evolution reaction performance and the overpotential of ZIF@HMCS-25% at 10 mA cm−2 is 407 mV. In addition, ZIF@HMCS-25% is further employed as an air electrode for a rechargeable Zn–air battery, exhibiting a high power density (120.2 mW cm−2 at 171.4 mA cm−2) and long-term charge/discharge stability (80 h at 5 mA cm−2). This MOFs@HMCS yolk–shell design provides a versatile method for the application of MOFs as electrocatalysts directly.


2021 ◽  
Author(s):  
Meng Ge ◽  
Yanzhi Wang ◽  
Francesco Carraro ◽  
Weibin Liang ◽  
Morteza Roostaeinia ◽  
...  

<p>Metal-organic frameworks (MOFs) are known for their versatile combination of inorganic building units and organic linkers, which offers immense opportunities in a wide range of applications. However, many MOFs are typically synthesized as multiphasic polycrystalline powders, which are challenging for studies by X-ray diffraction. Therefore, developing new structural characterization techniques is highly desired in order to accelerate discoveries of new materials. Here, we report a high-throughput approach for structural analysis of MOF nano- and sub-microcrystals by three-dimensional electron diffraction (3DED). A new zeolitic-imidazolate framework (ZIF), denoted ZIF-EC1<a>, </a>was first discovered in a trace amount during the study of a known ZIF-CO<sub>3</sub>-1 material by 3DED. The structures of both ZIFs were solved and refined using 3DED data. ZIF-EC1 has a dense 3D framework structure, which is built by linking mono- and bi-nuclear Zn clusters and 2-methylimidazolates (mIm<sup>-</sup>). With a composition of Zn<sub>3</sub>(mIm)<sub>5</sub>(OH), ZIF-EC1 exhibits high N and Zn densities. We show that the N-doped carbon material derived from ZIF-EC1 is a promising electrocatalysis for oxygen reduction reaction (ORR). The discovery of this new MOF and its conversion to an efficient electrocatalyst highlights the power of 3DED in developing new materials and their applications. </p>


2021 ◽  
Author(s):  
Wenjie Ma ◽  
Fei Wu ◽  
Ping Yu ◽  
Lanqun Mao

Metal-organic frameworks (MOFs) possess fantastic features such as structural diversity, tunable accessible pores and atomically dispersed active sites, holding tremendous potentials as high versatile platforms for fabricating single-site catalysts. The...


2021 ◽  
Author(s):  
Bahareh ameri ◽  
Akbar Mohammadi Zardkhoshoui ◽  
Saied Saeed Hosseiny Davarani

Metal-organic frameworks (MOFs) derived nanoarchitectures have special features, such as high surface area (SA), abundant active sites, exclusive porous networks, and remarkable supercapacitive performance when compared to traditional nanoarchitectures. Herein,...


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