02138nas a2200217   4500008004100000022001400041245010900055210006900164260006900233300001200302490000800314520131400322653001301636653002601649653002301675653002301698653002101721100002201742700002601764856013001790       2008                        eng d  a1385-894700aDirect oxidation of H-2 to H2O2 over Pd/CeO2 catalyst under ambient conditions: influence of halide ions0 aDirect oxidation of H2 to H2O2 over PdCeO2 catalyst under ambien  aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcMAR  a126-1320 v1363 a<p>Direct oxidation of H-2 by O-2 to H2O2 and decomposition/hydrogenation of H2O2 have been investigated over Pd/CeO2 catalyst in presence of different halide ions. All reactions were carried out in an aqueous acidic (0.03 M H3PO4) medium at room temperature (25 degrees C) and atmospheric pressure. When different halide ions were added directly to the reaction medium or incorporated in the catalyst, the activity/selectivity of Pd/CeO2 catalyst in the H-2 to H2O2 oxidation changed significantly, depending upon the nature of the halide ions. Different ammonium halides impregnated reduced Pd/CeO2 catalyst calcined under inert (flowing nitrogen) and oxidizing (static/flowing air) gaseous atmospheres revealed that bulk oxidation state of Pd and the nature of the halide ions incorporated into the catalyst cooperatively control the activity/selectivity of catalyst in H-2 to H2O2 oxidation. Both H2O2 decomposition and hydrogenation were found to affect strongly depending upon the nature of the halide ions present in the reaction medium or in the catalyst. Among the different halides, bromide was found the most effective promoter for enhancing the H2O2 yield/selectivity in H-2 to H2O2 oxidation, irrespective of the Pd oxidation state in the catalyst. (c) 2007 Elsevier B.V. All rights reserved.</p>10aBr- ions10aH-2 to H2O2 oxidation10aH2O2 decomposition10aH2O2 hydrogenation10aPd/CeO2 catalyst1 aSamanta, Chanchal1 aChoudhary, Vasant, R.  uhttps://library.ncl.res.in/content/direct-oxidation-h-2-h2o2-over-pdceo2-catalyst-under-ambient-conditions-influence-halide-0