@article { ISI:000325849000034, title = {Zeolitic imidazolate framework (ZIF)-derived, hollow-core, nitrogen-doped carbon nanostructures for oxygen-reduction reactions in PEFCs}, journal = {Chemistry-A European Journal}, volume = {19}, number = {28}, year = {2013}, month = {JUL}, pages = {9335-9342}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

The facile synthesis of a porous carbon material that is doped with iron-coordinated nitrogen active sites (FeNC-70) is demonstrated by following an inexpensive synthetic pathway with a zeolitic imidazolate framework (ZIF-70) as a template. To emphasize the possibility of tuning the porosity and surface area of the resulting carbon materials based on the structure of the parent ZIF, two other ZIFs, that is, ZIF-68 and ZIF-69, are also synthesized. The resulting active carbon material that is derived from ZIF-70, that is, FeNC-70, exhibits the highest BET surface area of 262m2g-1 compared to the active carbon materials that are derived from ZIF-68 and ZIF-69. The HR-TEM images of FeNC-70 show that the carbon particles have a bimodal structure that is composed of a spherical macroscopic pore (about 200nm) and a mesoporous shell. X-ray photoelectron spectroscopy (XPS) reveals the presence of Fe-N-C moieties, which are the primary active sites for the oxygen-reduction reaction (ORR). Quantitative estimation by using EDAX analysis reveals a nitrogen content of 14.5wt.\%, along with trace amounts of iron (0.1wt.\%), in the active FeNC-70 catalyst. This active porous carbon material, which is enriched with Fe-N-C moieties, reduces the oxygen molecule with an onset potential at 0.80V versus NHE through a pathway that involves 3.3-3.8e- under acidic conditions, which is much closer to the favored 4e- pathway for the ORR. The onset potential of FeNC-70 is significantly higher than those of its counterparts (FeNC-68 and FeNC-69) and of other reported systems. The FeNC-based systems also exhibit much-higher tolerance towards MeOH oxidation and electrochemical stability during an accelerated durability test (ADT). Electrochemical analysis and structural characterizations predict that the active sites for the ORR are most likely to be the insitu generated NFeN2+2/C moieties, which are distributed along the carbon framework.

}, keywords = {Doping, Electrochemistry, metal-organic frameworks, Nanostructures, oxygen-reduction reaction}, issn = {0947-6539}, doi = {10.1002/chem.201300145}, author = {Palaniselvam, Thangavelu and Biswal, Bishnu P. and Banerjee, Rahul and Kurungot, Sreekumar} } @article { ISI:000331774700017, title = {Two-in-one: inherent anhydrous and water-assisted high proton conduction in a 3D metal-organic framework}, journal = {Angewandte Chemie-International Edition}, volume = {53}, number = {10}, year = {2014}, month = {MAR}, pages = {2638-2642}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

The development of solid-state proton-conducting materials with high conductivity that operate under both anhydrous and humidified conditions is currently of great interest in fuel-cell technology. A 3Dmetal-organic framework (MOF) with acid-base pairs in its coordination space that efficiently conducts protons under both anhydrous and humid conditions has now been developed. The anhydrous proton conductivity for this MOF is among the highest values that have been reported for MOF materials, whereas its water-assisted proton conductivity is comparable to that of the organic polymer Nafion, which is currently used for practical applications. Unlike other MOFs, which conduct protons either under anhydrous or humid conditions, this compound should represent a considerable advance in the development of efficient solid-state proton-conducting materials that work under both anhydrous and humid conditions.

}, keywords = {conducting materials, fuel cells, metal-organic frameworks, porous materials, proton conduction}, issn = {1433-7851}, doi = {10.1002/anie.201309077}, author = {Nagarkar, Sanjog S. and Unni, SreeKuttan M. and Sharma, Amitosh and Kurungot, Sreekumar and Ghosh, Sujit K.} } @article {45723, title = {Single cell fabrication towards the realistic evaluation of a CNT-strung ZIF-derived electrocatalyst as a cathode material in alkaline fuel cells and metal-air batteries}, journal = {ChemElectroChem}, volume = {4}, year = {2017}, month = {NOV}, pages = {2928-2933}, type = {Article}, abstract = {

The development of an electrocatalyst possessing all the vital requisites of an ideal electrode material, such as high porosity, high conductivity, and high intrinsic electrochemical activity, holds a decisive key in determining the activity of the triplephase boundary in many energy devices like fuel cells and metal-air battery systems. In the present work, highly porous cobalt-based ZIFs are strung along the highly conducive CNT backbone by using a simple one-pot technique at room temperature, which is then utilized to derive a porous, corrosion-resistant, Co nanoparticle-embedded electrocatalyst. Herein, for the first time, the single cell performance of the Co-ZIF-67-derived electrocatalyst has been evaluated by fabricating membrane electrode assemblies of alkaline exchange membrane fuel cell (AEMFC) and zinc-air battery (ZAB) systems. A maximum power density of 296 mW/cm(2) (vs. 317 mW/cm(2) for 40 wt.\% Pt/C) and 60 mW/cm(2) (vs. 64 mW/cm(2) for 40 wt.\% Pt/C) in the single cells of ZAB and AEMFC systems, respectively, establishes the practical proficiency of the homemade electrocatalyst for cathode applications during realistic system-level validations.

}, keywords = {Batteries, Carbon nanotubes, Composite materials, fuel cells, metal-organic frameworks}, issn = {2196-0216}, doi = {10.1002/celc.201700562}, author = {Aiyappa, Harshitha Barike and Bhange, Siddheshwar N. and Sivasankaran, Vijitha P. and Kurungot, Sreekumar} } @article {48335, title = {2D layered nanomaterials as fillers in polymer composite electrolytes for lithium batteries}, journal = {Advanced Energy Materials}, volume = {13}, year = {2023}, month = {APR}, type = {Review}, abstract = {

Polymer composite electrolytes (PCEs), i.e., materials combining the disciplines of polymer chemistry, inorganic chemistry, and electrochemistry, have received tremendous attention within academia and industry for lithium-based battery applications. While PCEs often comprise 3D micro- or nanoparticles, this review thoroughly summarizes the prospects of 2D layered inorganic, organic, and hybrid nanomaterials as active (ion conductive) or passive (nonion conductive) fillers in PCEs. The synthetic inorganic nanofillers covered here include graphene oxide, boron nitride, transition metal chalcogenides, phosphorene, and MXenes. Furthermore, the use of naturally occurring 2D layered clay minerals, such as layered double hydroxides and silicates, in PCEs is also thoroughly detailed considering their impact on battery cell performance. Despite the dominance of 2D layered inorganic materials, their organic and hybrid counterparts, such as 2D covalent organic frameworks and 2D metal-organic frameworks are also identified as tuneable nanofillers for use in PCE. Hence, this review gives an overview of the plethora of options available for the selective development of both the 2D layered nanofillers and resulting PCEs, which can revolutionize the field of polymer-based solid-state electrolytes and their implementation in lithium and post-lithium batteries.

}, keywords = {2D materials, clay minerals, covalent organic frameworks, metal-organic frameworks, MXene, polymer composite electrolyte, solid-state batteries}, issn = {1614-6832}, doi = {10.1002/aenm.202203326}, author = {Vijayakumar, Vidyanand and Ghosh, Meena and Asokan, Kiran and Sukumaran, Santhosh Babu and Kurungot, Sreekumar and Mindemark, Jonas and Brandell, Daniel and Winter, Martin and Nair, Jijeesh Ravi} }