01226nas a2200193   4500008004100000022001400041245017100055210006900226260006100295300001000356490000700366520039900373653003400772653002200806653003300828100002600861700001600887856012900903       2005                        eng d  a1011-372X00aHydrogen peroxide formation in the interaction of oxygen with boron-containing Pd catalysts prereduced by hydrazine in aqueous acidic medium containing bromide anions0 aHydrogen peroxide formation in the interaction of oxygen with bo  a233 SPRING STREET, NEW YORK, NY 10013 USAbSPRINGERcJAN  a79-810 v993 a<p>Interaction of molecular oxygen with Pd/BPO4 or ZrO2 (or Al2O3, CeO2, TiO2) - B2O3 catalysts, prereduced by hydrazine hydrate, in an aqueous acidic (H2SO4 or H3PO4) reaction medium containing bromide ions leads to the formation of H2O2. However, in the absence of boron in the catalyst and also in the absence of acid and/or bromide ions in the reaction medium, almost no H2O2 is formed.</p>10aboron-containing Pd catalysts10aHydrogen peroxide10aoxygen-catalyst interactions1 aChoudhary, Vasant, R.1 aSamanta, C.  uhttps://library.ncl.res.in/content/hydrogen-peroxide-formation-interaction-oxygen-boron-containing-pd-catalysts-prereduced-002597nas a2200229   4500008004100000022001400041245017300055210006900228260007300297300001000370490000800380520164400388653002602032653005202058653002202110653002602132653001302158100002602171700002202197700001802219856013002237       2007                        eng d  a0926-860X00aDecomposition and/or hydrogenation of hydrogen peroxide over Pd/Al2O3 catalyst in aqueous medium: factors affecting the rate of H2O2 destruction in presence of hydrogen0 aDecomposition andor hydrogenation of hydrogen peroxide over PdAl  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcNOV  a70-780 v3323 a<p>Hydrogen peroxide destruction by its decomposition and/or hydrogenation to water in the presence of H-2 over Pd(5 wt.%)/Al2O3 catalyst in an aqueous reaction medium, similar to that used in the H-2-to-H2O2 oxidation, has been thoroughly investigated at different reaction conditions. The H2O2 destruction is strongly influenced by the oxidation state of Pd in the catalyst and also by the presence of different halide anions (viz. F-, Cl-, Br- and I-) in the acidic aqueous medium or in the catalyst, depending upon the concentration of halide anions. The cations associated with halide anions have, however, a little or no influence on the H2O2 destruction. The iodide anions strongly poisoned the catalyst, even at their very low concentration. The fluoride anions have only a small effect on the H2O2 destruction. The chloride or bromide anions drastically inhibit the rapid H2O2 decomposition, but promote the slower H2O2 hydrogenation. The H2O2 destruction reactions are strongly influenced by the halide anion and acid concentrations. The presence of acid (protons) plays a very important role in drastically reducing the H2O2 destruction, particularly in the presence of chloride anions. Both in the presence and absence of Cl- or Br- anions, the H2O2 destruction activity of the catalyst is markedly reduced because of the oxidation of Pd but it is drastically increased due to the presence of H-2. A plausible reaction mechanism for the rapid H2O2 decomposition and slower H2O2 hydrogenation reactions, prevailing under the different reaction conditions, has also been discussed. (C) 2007 Elsevier B.V. All rights reserved.</p>10adecomposition of H2O210ahalide anions as catalyst promoter or indicator10aHydrogen peroxide10ahydrogenation of H2O210aPd/Al2O31 aChoudhary, Vasant, R.1 aSamanta, Chanchal1 aJana, Prabhas  uhttps://library.ncl.res.in/content/decomposition-andor-hydrogenation-hydrogen-peroxide-over-pdal2o3-catalyst-aqueous-medium-002462nas a2200205   4500008004100000022001400041245025900055210006900314260007300383300001000456490000800466520149200474653003101966653002201997653002902019653003402048100002602082700001802108856013002126       2007                        eng d  a0926-860X00aDirect oxidation of H-2 to H2O2 over Br and F-promoted Pd/Al2O3 in aqueous acidic medium: influence of the concentration of Br and F and the method of incorporation of the two halogens in the catalyst on their beneficial synergetic effect on the net H2O20 aDirect oxidation of H2 to H2O2 over Br and Fpromoted PdAl2O3 in   aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcOCT  a79-850 v3293 a<p>Influence of the addition of F (0-1.1 mmol/g) in the pre-brominated Pd/Al2O3 (Br loading = 0.13 mmol/g) and also that of Br (0.13 mmol/g) in the pre-fluorinated Pd/Al2O3 (F loading = 0.53 mmol/g) on the net H2O2 formation in the H-2-to-H2O2 oxidation (with H-2/O-2 mole ratio of 1.0) over the halogenated catalysts in aqueous acidic (0.1 M H3PO4) medium have been investigated. In both the cases, the highest synergetic effect (resulting in the highest net H2O2 formation) produced by the addition of other halogen is observed at its optimum concentration (viz. 0.13 mmol Br/g in the fluorinated Pd/Al2O3 and 0.13 mmol F/g in the pre-brominated Pd/Al2O3). The beneficial synergetic effect of the two halogens is also found to be strongly influenced by the way of incorporation of the two halogens in the catalyst. The enhancement in the net rate of H2O2 formation due to the synergetic effect for the different methods of Pd/Al2O3 halogenation is in the following order: simultaneous bromination and fluorination &lt; first fluorination and then bromination &lt; first bromination and then fluorination. The fluorination (at optimum concentration of 0.13 mmol F/g) of the pre-brominated (0.13 mmol Br/g) Pd/Al2O3 led to the best catalyst for the H-2-to-H2O2 oxidation with 100% H-2 conversion and 78% H2O2 yield/selectivity. The destruction of H2O2 by its decomposition and/or hydrogenation over the halogenated catalysts has also been studied. (c) 2007 Published by Elsevier B.V.</p>10aF and Br-promoted Pd/Al2O310aHydrogen peroxide10aoxidation of H-2-to-H2O210asynergetic effect of F and Br1 aChoudhary, Vasant, R.1 aJana, Prabhas  uhttps://library.ncl.res.in/content/direct-oxidation-h-2-h2o2-over-br-and-f-promoted-pdal2o3-aqueous-acidic-medium-influence-003284nas a2200241   4500008004100000022001400041245018000055210006900235260007300304300001200377490000800389520231000397653002302707653002302730653002702753653002202780653002902802653001802831100002602849700002202875700001802897856012702915       2007                        eng d  a0926-860X00aFormation from direct oxidation of H-2 and destruction by decomposition/hydrogenation of H2O2 over Pd/C catalyst in aqueous medium containing different acids and halide anions0 aFormation from direct oxidation of H2 and destruction by decompo  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcFEB  a234-2430 v3173 a<p>Direct oxidation of H-2 by O-2 to H2O2 and decomposition/hydrogenation of H2O2 (at 27 degrees C and atmospheric pressure) over Pd/C catalyst in an aqueous acidic reaction medium have been thoroughly investigated using different mineral acids (viz. 0.1 N H2SO4, H3PO4, H3BO3, HNO3, HCl, HBr or HI) and/or halide anions (viz. F-, Cl-, Br- or I-), covering their wide concentration range (0-24 mmol/dm(3)), in the reaction medium. In the absence of any externally added halide, appreciable H2O2 formation in the H2 oxidation occurred only when the medium contained HCl. However, the rates of H2O2 decomposition and hydrogenation are greatly reduced because of the presence of any acid; the influence on the H2O2 decomposition was, however, much larger for the halo acids. In the presence of acid (0.1 N H3PO4 or H2SO4), the H-2-to-H2O2 formation reaction is greatly enhanced by the externally added halide anions up to their optimum concentrations. However, above the optimum halide anion concentration, it is inhibited more than the H-2-to-water formation (parallel) reaction, causing a decrease in both the H2O2 yield and selectivity. Whereas, the H-2 conversion and H2O2 destruction activities of the catalyst are decreased continuously with increasing the halide anion (except F-) concentration. Among the halides, chloride is the best halide promoter for Pd/C catalyst in the H-2-to-H2O2 oxidation. At the optimum Cl-concentration (5.4 mmol/dm(3)), both the H-2 conversion and H2O2 yield are passed through a maximum and the H2O2 decomposition is greatly inhibited with increasing the phosphoric acid concentration. In the absence of either the chloride anions or the acid (or both) in the reaction medium, only a little or no H2O2 is formed in the H-2 oxidation and also the rate of H2O2 destruction is very fast, particularly in the presence of H-2; the rapid destruction of H2O2 is mainly due to its decomposition rather than its hydrogenation. The best H-2-to-H2O2 oxidation results are obtained at the optimum concentrations of both the acid and halide anions. In the presence of acid and chloride (or bromide) promoter, the H2O2 hydrogenation dominates the H2O2 destruction and hence the net H2O2 formation is mainly controlled by the H2O2 hydrogenation. (c) 2006 Published by Elsevier B.V.</p>10aH2O2 decomposition10aH2O2 hydrogenation10ahalide anion promoters10aHydrogen peroxide10aoxidation of H-2-to-H2O210aPd/C catalyst1 aChoudhary, Vasant, R.1 aSamanta, Chanchal1 aJana, Prabhas  uhttps://library.ncl.res.in/content/formation-direct-oxidation-h-2-and-destruction-decompositionhydrogenation-h2o2-over-pdc02229nas a2200241   4500008004100000022001400041245017300055210006900228260007300297300001200370490000800382520125300390653003301643653002201676653002201698653002801720653002101748653002201769100002601791700001801817700002201835856013001857       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<p>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.</p>10abrominated Pd/Al2O3 catalyst10ahydrazine sulfate10aHydrogen peroxide10ain situ H2O2 generation10aoxygen reduction10aPd/Al2O3 catalyst1 aChoudhary, Vasant, R.1 aJana, Prabhas1 aSamanta, Chanchal  uhttps://library.ncl.res.in/content/generation-hydrogen-peroxide-selective-reduction-oxygen-hydrazine-sulfate-over-br-promoted01558nas a2200229   4500008004100000022001400041245018500055210006900240260007300309300001400382490000600396520062400402653002201026653001801048653002601066653002801092653001101120653002101131100002601152700001801178856013201196       2007                        eng d  a1566-736700aIn situ generation of hydrogen peroxide from reaction of O-2 with hydroxylamine from hydroxylammonium salt in neutral aqueous or non-aqueous medium using reusable Pd/Al2O3 catalyst0 aIn situ generation of hydrogen peroxide from reaction of O2 with  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcNOV  a1578-15820 v83 a<p>In situ generation of H2O2 with high yield can be accomplished by reacting 02 with NH2OH from hydroxylammonium salt [NH2OH.HCl or (NH2OH)(2) . H2SO4] in a neutral aqueous medium using a reusable heterogeneous Pd (1.0 wt%)/Al2O3 catalyst, even at low temperature (10 degrees C), with the formation of harmless by-products (viz. N-2 and water). The presence of KCl or KBr in the medium has beneficial effect. The H2O2 generation is strongly influenced by the pH of medium, reaction period and temperature; best results are obtained at the optimum pH and reaction medium. (c) 2007 Elsevier B.V. All rights reserved.</p>10aHydrogen peroxide10ahydroxylamine10aHydroxylammonium salt10ain situ H2O2 generation10aoxygen10aPd/AlO3 catalyst1 aChoudhary, Vasant, R.1 aJana, Prabhas  uhttps://library.ncl.res.in/content/situ-generation-hydrogen-peroxide-reaction-o-2-hydroxylamine-hydroxylammonium-salt-neutral-001964nas a2200265   4500008004100000022001400041245017500055210006900230260007300299300001200372490000600384520095100390653002101341653001301362653001301375653001101388653002201399653001801421653002701439653002801466100002601494700001801520700002801538856013201566       2007                        eng d  a1566-736700aReduction of oxygen by hydroxylammonium salt or hydroxylamine over supported Au nanoparticles for in situ generation of hydrogen peroxide in aqueous or non-aqueous medium0 aReduction of oxygen by hydroxylammonium salt or hydroxylamine ov  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcMAY  a811-8160 v83 a<p>Reaction of O-2 with hydroxylamine or its salts over a number of supported gold catalysts containing An nanoparticles (at 10-70 degrees C) has been studied at atmospheric pressure for the in situ generation of H2O2 (required for organic oxidation reactions in the synthesis of fine/specialty chemicals) in aqueous (water) or non-aqueous medium. Hydrogen peroxide in high yields with harmless by-products (viz. water and nitrogen) can be generated in situ by the reduction Of O-2 by hydroxylammonium sulfate (or chloride) or hydroxylamine using the supported gold catalysts particularly Au/Gd2O3, Au/La2O3 and Au/MgO, in aqueous (water) or non-aqueous (viz. methanol) medium at close to ambient conditions. The reduction of O-2 by hydroxylammonium salt to H2O2, however, requires preneutralization of the salt by alkali; in the absence of the neutralization, only water is formed in the reaction. (c) 2006 Elsevier B.V. All rights reserved.</p>10aAu Nanoparticles10aAu/Gd2O310aAu/La2O310aAu/MgO10aHydrogen peroxide10ahydroxylamine10ahydroxylammonium salts10ain situ H2O2 generation1 aChoudhary, Vasant, R.1 aJana, Prabhas1 aBhargava, Suresh, Kumar  uhttps://library.ncl.res.in/content/reduction-oxygen-hydroxylammonium-salt-or-hydroxylamine-over-supported-au-nanoparticles-situ01681nas a2200241   4500008004100000022001400041245018800055210006900243260009500312300001200407490000800419520068600427653002601113653004201139653002101181653002201202653001301224653000901237653002201246100002601268700001801294856012701312       2007                        eng d  a0021-951700aSynergetic effect of two halogen promoters present in acidic reaction medium or catalyst on the H2O2 formation (in H-2-to-H2O2 oxidation) and destruction over Pd/C (or Al2O3) catalyst0 aSynergetic effect of two halogen promoters present in acidic rea  a525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USAbACADEMIC PRESS INC ELSEVIER SCIENCEcMAR  a434-4390 v2463 a<p>A strong synergetic effect of two different halide anions (F- and I-, Cl- and I-, Cl- and Br-, and F- and Br-) at optimum concentration in the catalyst or in an acidic reaction medium was observed in the H-2-to-H2O2 oxidation over Pd/C, Pd/Al2O3, and halogenated Pd/Al2O3 catalysts. The synergetic effect promote, the net H2O2 formation by inhibiting the H2O2 decomposition and hydrogenation reactions. The effect is most pronounced for the combination of fluoride (or chloride) and iodide anions. The Br (1 wt%)-F (1 wt%)-Pd (5 wt%)/Al2O3 catalyst showed very high H2O2 yield (59%)/selectivity (60%) in the H-2-to-H2O2 oxidation. (c) 2006 Elsevier Inc. All rights reserved.</p>10aH-2-to-H2O2 oxidation10aH2O2 decomposition H2O2 hydrogenation10ahalogen promoter10aHydrogen peroxide10aPd/Al2O310aPd/C10asynergetic effect1 aChoudhary, Vasant, R.1 aJana, Prabhas  uhttps://library.ncl.res.in/content/synergetic-effect-two-halogen-promoters-present-acidic-reaction-medium-or-catalyst-h2o201701nas a2200217   4500008004100000022001400041245017100055210006900226260005700295300001200352490000800364520082500372653002201197653003401219653001701253653000901270100002601279700001801305700002801323856013201351       2008                        eng d  a1011-372X00aDirect H(2)-to-H(2)O(2) oxidation in aqueous acidic medium containing Br promoter over Pd/Al(2)O(3) and Pd/C catalysts thermally pretreated under different conditions0 aDirect H2toH2O2 oxidation in aqueous acidic medium containing Br  a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcOCT  a296-3010 v1253 a<p>Influence of thermal pretreatments (under N(2), air or H(2) gas atmosphere at 500 degrees C or 700 degrees C) has been investigated for the Pd/Al(2)O(3) and Pd/Carbon catalysts in terms of its effect on their Pd particle size and performance in the H(2)-to-H(2)O(2) oxidation and H(2)O(2) destruction (by decomposition and/or hydrogenation) reactions in aqueous acidic medium containing Br promoter. The influence on the net H(2)O(2) formation is found to depend strongly upon the catalyst support due to support-Pd cluster interactions. For both the catalysts, the thermal treatments (except in air) caused a large increase in their Pd particle size. The increase in Pd particle size caused an increase in the H(2)O(2) formation activity of Pd/Al(2)O(3) but a decrease in the H(2)O(2) formation activity of Pd/C.</p>10aHydrogen peroxide10aoxidation of H(2) to H(2)O(2)10aPd/Al(2)O(3)10aPd/C1 aChoudhary, Vasant, R.1 aJana, Prabhas1 aBhargava, Suresh, Kumar  uhttps://library.ncl.res.in/content/direct-h2-h2o2-oxidation-aqueous-acidic-medium-containing-br-promoter-over-pdal2o3-and-pdc-002048nas a2200193   4500008004100000022001400041245021600055210006900271260007300340300001400413490000600427520117000433653002201603653002901625653002801654100002601682700001801708856012801726       2008                        eng d  a1566-736700aDirect oxidation of H-2 to H2O2 over different supported PdO catalysts in aqueous acidic medium: Influence of the reduction, calcination temperature and support of the catalyst on its net H2O2 formation activity0 aDirect oxidation of H2 to H2O2 over different supported PdO cata  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAPR  a1624-16290 v93 a<p>Effects of the catalyst reduction (by hydrazine), calcination temperature (400-800 degrees C) and support (viz. Al2O3, SiO2, CeO2, ZrO2, HP or HM) on the performance of supported PdO (2.5 wt%) catalyst in the H-2-to-H2O2 oxidation (with H-2:O-2 = 1: 1) in an aqueous acidic (0.1 M H3PO4) medium under ambient conditions have been investigated. All the supported PdO catalysts showed lower H2 conversion activity, but higher H2O2 selectivity, as compared to their reduced counter parts. The catalyst performance for the net H2O2 formation is strongly influenced by both the support and calcination temperature of the supported PdO catalysts. The catalysts calcined at 400 degrees C showed better performance. Among the catalysts, PdO/Al2O3 catalyst (calcined at 400 degrees C) showed the best performance (17.0% H2O2 yield) in the H-2-to-H2O2 oxidation. The influence of the calcination temperature of PdO/Al2O3 catalyst on its H2O2 decomposition and hydrogenation activities has also been investigated. Both the H2O2 decomposition and hydrogenation activities increased with increasing the calcination temperature. (C) 2008 Elsevier B.V. All rights reserved.</p>10aHydrogen peroxide10aoxidation of H-2 to H2O210asupported PdO catalysts1 aChoudhary, Vasant, R.1 aJana, Prabhas  uhttps://library.ncl.res.in/content/direct-oxidation-h-2-h2o2-over-different-supported-pdo-catalysts-aqueous-acidic-medium-001585nas a2200217   4500008004100000022001400041245021000055210006900265260007300334300001400407490000600421520066000427653003001087653002201117653002901139653001301168653001401181100002601195700001801221856012801239       2008                        eng d  a1566-736700aDirect oxidation of H-2 to H2O2 over PdO/Al2O3 catalysts in aqueous acidic medium: influence on H2O2 formation of Pd loading, calcination temperature and reduction of catalyst and presence of halide anions0 aDirect oxidation of H2 to H2O2 over PdOAl2O3 catalysts in aqueou  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAUG  a2371-23750 v93 a<p>Effects of the Pd loading (0.2-10 wt%), calcination temperature (400-900 degrees C) and reduction of PdO/Al2O3 on its performance in the H-2-to-H2O2 oxidation (with H-2/O-2 = 1:1) in an aqueous 0.1 M H3PO4 medium, in the absence and presence of different halide anions, under ambient conditions have been investigated. The effect of calcination temperature on the H2O2 formation varied depending upon the Pd loading. The influence of the different halide anions was found to depend strongly on the nature of halide anion (F-, Cl-, Br- or I-) and the oxidation state of Pd and its loading in the catalyst. (C) 2008 Elsevier B.V. All rights reserved.</p>10ahalide catalyst promoters10aHydrogen peroxide10aoxidation of H-2 to H2O210aPd/Al2O310aPdO/Al2O31 aChoudhary, Vasant, R.1 aJana, Prabhas  uhttps://library.ncl.res.in/content/direct-oxidation-h-2-h2o2-over-pdoal2o3-catalysts-aqueous-acidic-medium-influence-h2o2-002258nas a2200229   4500008004100000022001400041245016000055210006900215260007300284300001100357490000800368520134900376653002101725653002201746653001801768653002901786653002201815653002101837100002601858700001801884856012601902       2008                        eng d  a0926-860X00aFactors influencing the in situ generation of hydrogen peroxide from the reduction of oxygen by hydroxylamine from hydroxylammonium sulfate over Pd/alumina0 aFactors influencing the in situ generation of hydrogen peroxide   aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcFEB  a95-1020 v3353 a<p>Influence of the concentration of bromide (KBr) promoter, reaction period, temperature, catalyst loading and initial concentration of hydroxylammonium sulfate on the formation of H2O2 due to the reaction between hydroxylamine from the hydroxylammonium salt and molecular oxygen over Pd (1 wt%)/Al2O3 catalyst in a neutral aqueous medium at close to the ambient conditions has been investigated. Effect of pH and temperature on the destruction of H2O2, Occurring in the consecutive reactions, over the catalyst in the presence or absence of bromide promoter and hydroxylamine has also been studied. In the absence of O-2, the conversion of hydroxylamine by its decomposition over the catalyst increases sharply with increasing the pH, particularly above the pH of 7.0; at or below the pH of 7.0, it is quite small. The H2O2 destruction increases markedly with increasing the pH of medium and reaction temperature but it is found to decrease in the presence of hydroxylamine. For the highest net H2O2 formation, not only the optimum pH (7.0) of reaction medium but also the optimum other reaction conditions (viz. bromide promoter concentration, reaction period, temperature or catalyst loading) are necessary. The reaction path and mechanism for the generation of H2O2 have also been suggested. (C) 2007 Elsevier B.V. All rights reserved.</p>10aH2O2 destruction10aHydrogen peroxide10ahydroxylamine10aHydroxylammonium sulfate10aPd/Al2O3 catalyst10areduction of O-21 aChoudhary, Vasant, R.1 aJana, Prabhas  uhttps://library.ncl.res.in/content/factors-influencing-situ-generation-hydrogen-peroxide-reduction-oxygen-hydroxylamine-002497nas a2200217   4500008004100000022001400041245016500055210006900220260007300289300001000362490000800372520160500380653002701985653002302012653002302035653002302058653002202081100002602103700001802129856013202147       2009                        eng d  a0926-860X00aDirect H-2-to-H2O2 oxidation over highly active/selective Br-F-Pd/Al2O3 catalyst in aqueous acidic medium: Influence of process conditions on the H2O2 formation0 aDirect H2toH2O2 oxidation over highly activeselective BrFPdAl2O3  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJAN  a35-420 v3523 a<p>The influence of the O-2/H-2 mote ratio in the gaseous feed and also those of other reaction conditions [viz. concentration of H3PO4 (0-5 mol/dm(3)). temperature (5-50 degrees C, gas (H-2 and O-2) space velocity (5.8-23.4 h(-1)) and reaction time (0.1-8 h)] on the H2O2 formation in the H-2-to-H2O2 oxidation over the Br(1 wt%)-F(1 wt%)-Pd(5 wt%)/Al2O3 catalyst in an aqueous acidic (H3PO4) medium have been thoroughly investigated. The effects of the O-2/H-2 ratio, reaction temperature and acid concentration on the destruction of H2O2 by its decomposition and/or hydrogenation reactions over the catalyst in the acidic reaction medium have also been studied. The net H2O2 formation (H2O2 yield) over the catalyst passed through a maximum with increasing the acid concentration, the temperature or the O-2/H-2 feed ratio. However, it decreased markedly with increasing the gas space velocity or the reaction period. The H2O2 decomposition and hydrogenation activities of the catalyst increased appreciably with increasing the reaction temperature and decreased with increasing the acid concentration. The H2O2 destruction during the H-2-to-H2O2 oxidation increased with increasing the concentration of H-2 (relative to that of O-2) due to the increased H2O2 hydrogenation rate over the catalyst. The net H2O2 formation in the H-2-to-H2O2 oxidation decreased sharply with increasing the initial amount of H2O2 present in the reaction mixture. The presence of H2O2 and the higher H-2/O-2 ratios have detrimental effects on the net formation of H2O2. (C) 2008 Elsevier B.V. All rights reserved.</p>10aBr-F-Pd/Al2O3 catalyst10aH2O2 decomposition10aH2O2 hydrogenation10ahydrogen oxidation10aHydrogen peroxide1 aChoudhary, Vasant, R.1 aJana, Prabhas  uhttps://library.ncl.res.in/content/direct-h-2-h2o2-oxidation-over-highly-activeselective-br-f-pdal2o3-catalyst-aqueous-acidic-0