Boreskov Institute of Catalysis SB RAS, Novosibirsk, Russia

PP-28PRODUCTION OF HYDROGEN BY PHOTOCATALYTIC REFORMINGOF BIOMASS COMPONENTS AND DERIVATIVES IN AQUEOUSPt/TiO 2 SUSPENSIONSPanagiotopoulou P., Kondarides D.I., Verykios X.E.Department of Chemical Engineering, University of Patras, 26504 Patras, GreeceFax.: + 30 2610 991527; e-mail: dimi@chemeng.upatras.grPhotocatalytic degradation of organic compounds in solution usually takes placein the presence of atmospheric oxygen and utilizes the strong oxidation potential ofphotogenerated holes to progressively degrade organic compounds into CO 2 andinorganic ions. Photogenerated electrons are believed to reduce oxygen adsorbed onthe photocatalyst surface and generate additional oxidizing species, which alsoparticipate in the degradation process. However, if the reaction takes place underunaerated conditions, the reduction potential of photogenerated electrons may beutilized to generate hydrogen by reduction of water. Under these conditions, theoverall process may be described by the following «photo-reforming» reaction:hν ≥E ( )bg( )CHOx y z+ 2x−z HO⎯⎯⎯⎯→ xCO + 2 x− z+ y/2 H22 photocatalyst2In the present study we investigate photo-reforming of a variety of organiccompounds in aqueous Pt/TiO 2 suspensions irradiated by a solar light-simulatingsource. Results show that waste biomass components and derivatives, such asalcohols, organic acids and carbohydrates, can be degraded effectively underunaerated conditions with simultaneous production of hydrogen. The rate ofhydrogen evolution (r H2 ) depends strongly on the nature and initial concentration ofthe organic compound in solution and, to a lesser extend, on solution pH andtemperature. Depending on the experimental conditions employed, r H2 can be morethan two orders of magnitude higher, compared to that obtained from pure water,rendering the process suitable for practical application. The photo-reforming processis non-selective and practically all organic compounds investigated so far may bedegraded in the absence of oxygen. The process can be applied for the production ofhydrogen from surplus of waste materials from biomass processing industries,practical feedstocks or glycerol-containing liquors derived from biodiesel plants, withminimum purification. It may also provide an efficient and cost effective method forcleaning up wastewaters with simultaneous production of hydrogen fuel.117