title: Effect of support and second metal in catalytic in-situ generation of hydrogen peroxide by Pd-supported catalysts: application in the removal of organic pollutants by means of the Fenton process.
abstract: A catalytic system for the generation of H2O2 from formic acid and oxygen at ambient conditions has been developed. Pd-supported catalysts (Pd/C, Pd/TiO2 and Pd/Al2O3) have been tested, showing that for bulk purposes Pd/Al2O3 is more favourable while for in-situ applications Pd/TiO2 seems to be preferable. However, when these catalysts were tested in the in-situ H2O2 generation for the oxidation of phenol by means of the Fenton process (in the presence of ferrous ion), Pd/TiO2 did not demonstrate the expected results, whereas Pd/Al2O3 showed to be an efficient catalyst. Therefore, Pd/Al2O3 is offered as a good catalyst for Fenton's reactions with in-situ generated H2O2. In order to optimize the operating cost of the process, different initial concentrations of formic acid have been tested with Pd/Al2O3, and it has been seen that lowering the initial amount of formic acid favours the efficiency of the process. The effect of the addition of a second metallic (Pt, Au, Fe, Cu) active phase was studied. Concerning H2O2 generation, best results were obtained with a Pd-Au catalyst for bulk production (long time) while for in-situ application Pd-Fe showed interesting results. The Pd-Fe catalyst also performed similarly to the semi-heterogeneous Fenton system involving Pd/Al2O3 and ferrous ion in the degradation of phenol. Therefore, Pd-Fe catalyst offered an interesting prospect for making a full heterogeneous catalyst for Fenton reaction involving in-situ generation of H2O2.
authors: Departament d'Enginyeria Química, Universitat Rovira i Virgili, Avda. Països Catalans, 26, Campus Sescelades, Tarragona 43007, Spain. sandra.contreras@urv.cat
authors: S
authors: S
authors: Contreras
authors: M S
authors: MS
authors: Yalfani
authors: F
authors: F
authors: Medina
authors: J E
authors: JE
authors: Sueiras
mesh_terms: D002384:Catalysis; D005561:Formates; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007501:Iron; D046529:Microscopy, Electron, Transmission; D010100:Oxygen; D010165:Palladium / Q000737:chemistry*; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: C045076:Fenton's reagent; D005561:Formates; D014874:Water Pollutants, Chemical; C030544:formic acid; D010165:Palladium; D006861:Hydrogen Peroxide; D007501:Iron; D010100:Oxygen