02005nas a2200301 4500008004100000022001400041245016600055210006900221260000800290300001600298490000600314520094300320653002301263653001901286653001901305653003001324653001801354653001001372100001801382700002601400700002401426700002401450700003101474700003001505700002101535700002001556856012701576 2016 eng d a1944-824400aGraphene oxide sheathed ZIF-8 microcrystals: engineered precursors of nitrogen-doped porous carbon for efficient oxygen reduction reaction (ORR) electrocatalysis0 aGraphene oxide sheathed ZIF8 microcrystals engineered precursors cNOV a29373-293820 v83 a

Nitrogen containing mesoporous carbon obtained by the pyrolysis of graphene oxide (GO) wrapped ZIF-8 (Zeolitic Imidazolate Frameworks-8) micro crystals is demonstrated to be an efficient catalyst for the oxygen reduction reaction (ORR). ZIF-8 synthesis in the presence of GO sheets helped to realize layers of graphene oxide over ZIF-8 microcrystals and the sphere-like structures thus obtained, on heat treatment, transformed to highly porous carbon with a nitrogen content of about 6.12% and surface area of 502 m(2)/g. These catalysts with a typical micromeso porous architecture exhibited an onset potential of 0.88Vvs RHE in a four electron pathway and also demonstrated superior durability in alkaline medium compared to that of the commercial Pt/C catalyst. The N-doped porous carbon derived from GO sheathed ZIF-8 core shell structures could therefore be employed as an efficient electrocatalyst for fuel cell applications.

10aalkaline fuel cell10agraphene oxide10aN-doped carbon10aoxygen reduction reaction10aporous carbon10aZIF-81 aThomas, Minju1 aIllathvalappi, Rajith1 aKurungot, Sreekumar1 aNair, Balagopal, N.1 aMohamed, Abdul, Azeez Peer1 aAnilkumar, Gopinathan, M.1 aYamaguchi, Takeo1 aHareesh, U., S. uhttps://library.ncl.res.in/content/graphene-oxide-sheathed-zif-8-microcrystals-engineered-precursors-nitrogen-doped-porous02503nas a2200289 4500008004100000022001400041245016700055210006900222260000800291300001400299490000600313520146900319653002001788653001401808653002201822653003001844100002501874700002701899700002401926700002401950700001801974700002101992700003002013700002002043700002002063856013002083 2017 eng d a2365-654900aChitosan intercalated metal organic gel as a green precursor of fe entrenched and fe distributed N-doped mesoporous graphitic carbon for oxygen reduction reaction0 aChitosan intercalated metal organic gel as a green precursor of  cSEP a8762-87700 v23 a

Herein, we present Metal-Organic Gel intercalated with chitosan, a `green'' precursor for the synthesis of intrinsic N-doped Fe entrenched (CHI-TMA-Fe-CW) and Fe distributed mesoporous graphitic carbon structures (CHI-TMA-Fe-CW-M1) with appreciable Oxygen Reduction Reaction (ORR) activity in alkaline medium. Modulation of the synthetic protocol as a function of reaction kinetics and gelation time while maintaining identical pyrolysis conditions (900 degrees C, flowing N-2 atmosphere) improves the microstructure, surface area and Fe distribution of the graphitic structures (CHI-TMA-Fe-CW-M1). CHI-TMA-Fe-CW has a Fe entrenched graphitic nanocapsule like morphology while Fe distributed mesoporous graphitic carbon sheets, with a specific surface area value of 565 m(2) g(-1) obtained by modulating the synthesis chemistry in CHI-TMA-Fe-CW-M1. The higher percentage of graphitic N in CHI-TMA-Fe-CW-M1 apparent from the XPS data validate that the modified synthetic method favours creation of more graphitic N sites contributing for better catalytic performance. CHI-TMA-Fe-CW-M1 catalyst exhibited comparable electrocatalytic activity with that of the commercially available Pt/C via an efficient four-electron-dominant ORR pathway with a positive onset potential value of 0.925 V vs RHE. Good durability of CHI-TMA-Fe-CW-M1 after 5000 cycles further confirm the prospects of MOG-chitosan and the feasibility to be used as a potential catalyst for ORR.

10aelectrocatalyst10afuel cell10aMetal-Organic-Gel10aoxygen reduction reaction1 aShijina, Kottarathil1 aIllathvalappil, Rajith1 aKurungot, Sreekumar1 aNair, Balagopal, N.1 aMohamed, Peer1 aYamaguchi, Takeo1 aAnilkumar, Gopinathan, M.1 aHareesh, U., S.1 aSailaja, G., S. uhttps://library.ncl.res.in/content/chitosan-intercalated-metal-organic-gel-green-precursor-fe-entrenched-and-fe-distributed-n02199nas a2200253 4500008004100000022001400041245017700055210006900232260000800301300001600309490000700325520125400332100002501586700002601611700002001637700002001657700002401677700002401701700001801725700003001743700002201773700002001795856013001815 2018 eng d a1144-054600aMelamine formaldehyde-metal organic gel interpenetrating polymer network derived intrinsic Fe-N-doped porous graphitic carbon electrocatalysts for oxygen reduction reaction0 aMelamine formaldehydemetal organic gel interpenetrating polymer  cDEC a18690-187010 v423 aFe, N doped porous graphitic carbon electrocatalyst (Fe-MOG-MF-C), obtained by pyrolysis of an Interpenetrating Polymer Network (IPN) comprised of melamine formaldehyde (MF as hard segment) and Metal-Organic Gel (MOG as soft segment), exhibited significant Oxygen Reduction Reaction (ORR) activity in alkaline medium. BET surface area analysis of Fe-MOG-MF-C showed high surface area (821 m(2) g(-1)), while TEM, Raman and XPS results confirmed Fe and N co-doping. Furthermore, a modulated porous morphology with a higher degree of surface area (950 m(2) g(-1)) has been accomplished for the system (Fe-MOG-MFN-C) when aided by a sublimable porogen, such as naphthalene. XPS results further demonstrated that these systems exhibited a better degree of distribution of graphitic N and an onset potential value of 0.91 V vs. RHE in 0.1 M KOH solution following an efficient four-electron ORR pathway. The electrocatalytic activity of Fe-MOG-MFN-C is superior to that of Fe-MOG-MF-C by virtue of its higher graphitic N content and surface area. Thus, the study presents a new class of IPN derived MF-MOG nanocomposites with the potential to generate extended versions of in situ Fe-N doped porous graphitic carbon structures with superior ORR activity.1 aShijina, Kottarathil1 allathvalappil, Rajith1 aSumitha, N., S.1 aSailaja, G., S.1 aKurungot, Sreekumar1 aNair, Balagopal, N.1 aMohamed, Peer1 aAnilkumar, Gopinathan, M.1 aYamaguchig, Takeo1 aHareesh, U., S. uhttps://library.ncl.res.in/content/melamine-formaldehyde-metal-organic-gel-interpenetrating-polymer-network-derived-intrinsic02277nas a2200289 4500008004100000022001400041245014000055210006900195260000800264300001400272490000600286520128800292653002001580653001401600653002601614653003001640653001001670100001801680700002701698700002401725700002401749700001801773700003001791700002101821700002001842856012501862 2018 eng d a2365-654900aMorphological ensembles of N-doped porous carbon derived from ZIF-8/Fe-graphene nanocomposites: processing and electrocatalytic studies0 aMorphological ensembles of Ndoped porous carbon derived from ZIF cAUG a8688-86970 v33 a

Engineering the active site density of porous carbon catalysts for enhanced electrocatalytic activity is the current focus in the quest for economically viable fuel cells. Herein, we synthesise ZIF-8/Fe-graphene composites for the formation of N and Fe co-doped carbon with diverse morphologies ranging from tubes and sheets to frameworks of carbon. A synthetic strategy involving the one pot synthesis of ZIF-8 based composites is accomplished by the reaction of 2-methylimidazole with mixed Zn/Fe salt solution containing graphene dispersions. The high temperature heat treatment of this precursor mix yielded micro-meso porous architectures of N, Fe co-doped carbon with dispersions of Fe/Fe3C. An onset potential value of 0.95 V and a half-wave potential of 0.82 V coupled with excellent durability and stability in alkaline medium indicated improved electrocatalytic performances over its commercial Pt/C counterpart. The appreciable electrocatalytic properties of the synthesized carbon are attributed to its morphological diversity, hybrid structure, high N doping and its heteroporous characteristics. The dispersed Fe/Fe3C and FeNx sites facilitated enhanced oxygen adsorption and the graphene inclusions in the composite provided retention of high nitrogen contents.

10aelectrocatalyst10afuel cell10aN- Fe co-doped carbon10aoxygen reduction reaction10aZIF-81 aThomas, Minju1 aIllathvalappil, Rajith1 aKurungot, Sreekumar1 aNair, Balagopal, N.1 aMohamed, Peer1 aAnilkumar, Gopinathan, M.1 aYamaguchi, Takeo1 aHareesh, U., S. uhttps://library.ncl.res.in/content/morphological-ensembles-n-doped-porous-carbon-derived-zif-8fe-graphene-nanocomposites02343nas a2200253 4500008004100000022001400041245014800055210006900203260000900272300001600281490000700297520143700304100002301741700001801764700002701782700001601809700002401825700002401849700001801873700003001891700002101921700002001942856012701962 2020 eng d a1144-054600aTemplate assisted synthesis of Ni,N co-doped porous carbon from Ni incorporated ZIF-8 frameworks for electrocatalytic oxygen reduction reaction0 aTemplate assisted synthesis of NiN codoped porous carbon from Ni cJUL  a12343-123540 v443 a

A heteroatom doped porous carbon electrocatalyst with enhanced oxygen reduction reaction (ORR) performance in alkaline medium was obtained by high temperature treatment of Ni incorporated ZIF-8 frameworks and its composite with g-C(3)N(4)as a supporting matrix template. The morphology and porosity of this heteroatom containing carbon were tuned by varying the Ni : Zn molar ratio in Ni/Zn ZIF-8 and Ni/Zn ZIF-8@g-C(3)N(4)composites. The template aided synthetic strategy using g-C(3)N(4)helped in the controlled decomposition of composites leading to a heteroporous sheet like architecture with increased nitrogen content. The Ni/Zn ZIF-8 sample on heat treatment in the 800-1000 degrees C temperature range led to the formation of Ni,N co-doped porous carbon (Ni-NPC) with Ni-C active sites. The defective sites induced by nickel carbide along with the distributed N atoms on the carbon surface enabled active O(2)adsorption sites. The high surface area, high degree of graphitisation as well as the defects created by well dispersed N and Ni on porous carbon matrices favoured charge separation leading to higher electrochemical ORR activity. The Ni,N co-doped carbon catalyst in alkaline medium exhibited a limiting current density of 5.2 mA cm(-2)with a half-wave potential of 0.76 Vvs.RHE in 0.1 M KOH. The catalyst also showed improved methanol tolerance and better stability compared to the standard Pt/C catalyst.

1 aK., Vaishna, Priya1 aThomas, Minju1 aIllathvalappil, Rajith1 aK., Shijina1 aKurungot, Sreekumar1 aNair, Balagopal, N.1 aMohamed, Peer1 aAnilkumar, Gopinathan, M.1 aYamaguchi, Takeo1 aHareesh, U., S. uhttps://library.ncl.res.in/content/template-assisted-synthesis-nin-co-doped-porous-carbon-ni-incorporated-zif-8-frameworks