02228nas a2200241 4500008004100000022001400041245017300055210006900228260007300297300001200370490000800382520125300390653003301643653002201676653002201698653002801720653002101748653002201769100002601791700001801817700002201835856012901857 2007 eng d a0926-860X00aGeneration of hydrogen peroxide via the selective reduction of oxygen by hydrazine sulfate over Br-promoted Pd/Al2O3 catalyst in an aqueous medium at ambient conditions0 aGeneration of hydrogen peroxide via the selective reduction of o aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAPR a202-2090 v3233 a

The in situ generation of H2O2 via the selective reduction of OZ by hydrazine sulfate (in an aqueous medium) has been thoroughly investigated over the Br-promoted Pd(or PdO)/Al2O3 catalyst. The influence of the following factors have been addressed in this study: (a) Br concentration (in the reaction medium or incorporated in the catalyst); (b) reaction conditions (viz. reaction time, temperature); (c) concentrations of reducing agent and phosphoric acid in the reaction medium. Decomposition of N2H4 (from NH4-H2SO4) and its reaction with H2O2 under similar reaction conditions (in the absence of O-2) have also been studied. H2O2, which is an intermediate product of the O-2 reduction, is involved in further consecutive reactions. It can be converted to water via its decomposition and/or reaction with the unconverted NZH(4). In the presence of Br promoter, the later (reaction with unconverted N2H4) is more dominant. Both the consecutive reactions are drastically retarded in the presence of protons and Br promoter. A plausible reaction mechanism has been proposed for illustrating the role of the protons and Br promoter in the selective formation of H2O2 in the O-2 reduction process. (C) 2007 Elsevier B.V. All rights reserved.

10abrominated Pd/Al2O3 catalyst10ahydrazine sulfate10aHydrogen peroxide10ain situ H2O2 generation10aoxygen reduction10aPd/Al2O3 catalyst1 aChoudhary, Vasant, R.1 aJana, Prabhas1 aSamanta, Chanchal uhttp://library.ncl.res.in/content/generation-hydrogen-peroxide-selective-reduction-oxygen-hydrazine-sulfate-over-br-promoted02798nas a2200253 4500008004100000022001400041245015200055210006900207260007100276300001400347490000600361520184700367653002102214653002002235653001002255653002802265653002102293653002302314100001602337700001502353700003002368700001502398856013102413 2014 eng d a1944-824400aFacile single-step synthesis of nitrogen-doped reduced graphene oxide-Mn3O4 hybrid functional material for the electrocatalytic reduction of oxygen0 aFacile singlestep synthesis of nitrogendoped reduced graphene ox a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcFEB a2692-26990 v63 a

Development of efficient electrocatalyst based on non-precious metal that favors the four-electron pathway for the reduction of oxygen in alkaline fuel cell is a challenging task. Herein, we demonstrate a new facile route for the synthesis of hybrid functional electrocatalyst based on nitrogen-doped reduced graphene oxide (N-rGO) and Mn3O4 with pronounced electrocatalytic activity towards oxygen reduction reaction (ORR) in alkaline solution. The synthesis involves one-step in situ reduction of both graphene oxide (GO) and Mn(VII), growth of Mn3O4 nanocrystals and nitrogen doping onto the carbon framework using a single reducing agent, hydrazine. The X-ray photoelectron (XPS), Raman and FTIR spectral, and X-ray diffraction measurements confirm the reduction of GO and growth of nanosized Mn3O4. The XPS profile reveals that N-rGO has pyridinic (40%), pyrrolic (53%), and pyridine N oxide (7%) types of nitrogen. The Mn3O4 nanoparticles are single crystalline and randomly distributed over the wrinkled N-rGO sheets. The hybrid material has excellent ORR activity and it favors the 4-electron pathway for the reduction of oxygen. The electrocatalytic performance of the hybrid catalyst is superior to the N-rGO, free Mn3O4 and their physical mixture. The hybrid material shows an onset potential of -0.075 V, which is 60-225 mV less negative than that of the other catalyst tested. It has excellent methanol tolerance and high durability. The catalytic current density achieved with the hybrid material at 0.1 mg cm(-2) is almost equivalent to that of the commercial Pt/C (10%). The synergistic effect of N-rGO and Mn3O4 enhances the overall performance of the hybrid catalyst. The nitrogen in N-rGO is considered to be at the interface to bridge the rGO framework and Mn3O4 nanoparticles and facilitates the electron transfer.

10aelectrocatalysis10ahybrid material10aMn3O410anitrogen-doped graphene10aoxygen reduction10asynergistic effect1 aBag, Sourav1 aRoy, Kanak1 aGopinath, Chinnakonda, S.1 aRaj, Retna uhttp://library.ncl.res.in/content/facile-single-step-synthesis-nitrogen-doped-reduced-graphene-oxide-mn3o4-hybrid-functional-001878nas a2200289 4500008004100000022001400041245012100055210006900176260000800245300001200253490000700265520093700272653002001209653002101229653001401250653001901264653002101283653002101304100001901325700002001344700001601364700001501380700001801395700002301413700002501436856012701461 2021 eng d a2155-543500aUnveiling the roles of lattice strain and descriptor species on pt-like oxygen reduction activity in Pd-Bi catalysts0 aUnveiling the roles of lattice strain and descriptor species on  cJAN a800-8080 v113 a

A facile non-template-assisted mechanical ball milling technique was employed to generate a PdBi alloy catalyst. The induced lattice strain upon the milling time caused a shift of the d-band center, thereby enhancing the oxygen reduction reaction (ORR) catalytic activity. Additionally, the Pd-O reduction potential and adsorbed OH coverage used as descriptors stipulated the cause of the enhanced ORR activity upon the increased milling interval. Redox properties of surface Pd are directly correlated with a positive shift in the Pd-O reduction potential and OH surface coverage. Hence, by deconvoluting the lattice strain and the role of the descriptor species we achieved a catalyst system with a specific activity 5.4X higher than that of commercial Pt/C, as well as an improved durability. The experimental observation is well-corroborated by a theoretical simulation done by inducing strain to the system externally.

10acharge-transfer10aelectrocatalysis10afuel cell10aLattice strain10aoxygen reduction10aPt-like activity1 aSarkar, Shreya1 aRamarao, S., D.1 aDas, Tisita1 aDas, Risov1 aVinod, C., P.1 aChakraborty, Sudip1 aPeter, Sebastian, C. uhttp://library.ncl.res.in/content/unveiling-roles-lattice-strain-and-descriptor-species-pt-oxygen-reduction-activity-pd-bi