185 nm photoreduction of CO2 to methane by water. Influence of the presence of a basic catalyst.

Photolysis of CO(2) at 185 nm using a Hg lamp in the presence of H(2) or H(2)O leads to the formation of CH(4) (after an induction period) and a lesser amount of CO. Using H(2) gas as reducing agent, up to 40% conversion was achieved with almost complete selectivity to methane and energy consumption of 1.55 Gcal/mol. When CO(2) irradiation is carried out in the gas phase in the presence of H(2)O, both reagents can undergo photolysis, and H(2) generation from water is a competing process accompanying the formation of CO and CH(4) (CO(2) conversion 0.67% at 14 h). For the irradiation of CO(2) using H(2)O as reducing agent, basic solids (K(+)-exchanged Y zeolite or hydrotalcites) can increase CO(2) conversion up to 2.21% with total selectivity toward CH(4) and an energy consumption of 4.5 Gcal/mol. This result opens a door in the quest for efficient photocatalysts that could further increase the apparent quantum yield of the process, particularly at longer wavelengths.

[1]  Nick Serpone,et al.  Solar fuels: Status and perspectives , 1992 .

[2]  D. Barthomeuf,et al.  Basic zeolites : Characterization and uses in adsorption and catalysis , 1996 .

[3]  A. Fujishima,et al.  TiO2 photocatalysis and related surface phenomena , 2008 .

[4]  H. García,et al.  Sunlight-assisted Fenton reaction catalyzed by gold supported on diamond nanoparticles as pretreatment for biological degradation of aqueous phenol solutions. , 2011, ChemSusChem.

[5]  H. García,et al.  Improving TiO 2 activity in photo-production of hydrogen from sugar industry wastewaters , 2011 .

[6]  Jean-Claude Lavalley,et al.  Infrared spectrometric studies of the surface basicity of metal oxides and zeolites using adsorbed probe molecules , 1996 .

[7]  A. Corma,et al.  Selective, room-temperature transformation of methane to C1 oxygenates by deep UV photolysis over zeolites. , 2011, Journal of the American Chemical Society.

[8]  H. Hartman,et al.  Synthesis of organic compounds from carbon monoxide and water by UV photolysis , 1978, Origins of life.

[9]  Lucie Obalová,et al.  Effect of TiO2 particle size on the photocatalytic reduction of CO2 , 2009 .

[10]  Hiromi Yamashita,et al.  Photocatalytic reduction of CO2 with H2O on various titanium oxide photocatalysts , 2012 .

[11]  Siglinda Perathoner,et al.  Towards solar fuels from water and CO2. , 2010, ChemSusChem.

[12]  Chunshan Song.  Global challenges and strategies for control, conversion and utilization of CO2 for sustainable development involving energy, catalysis, adsorption and chemical processing , 2006 .

[13]  M. Graetzel,et al.  Artificial photosynthesis: water cleavage into hydrogen and oxygen by visible light , 1981 .

[14]  P. Warneck.  Reactions of 1D oxygen atoms in the photolysis of carbon dioxide , 1964 .

[15]  R. Reeves,et al.  Photochemical Equilibrium Studies of Carbon Dioxide and Their Significance for the Venus Atmosphere , 1966 .

[16]  Bruce H. Mahan,et al.  Photolysis of Carbon Dioxide , 1960 .

[17]  Sang-Eon Park,et al.  Photoreduction of Carbondioxide on Surface Functionalized Nanoporous Catalysts , 2005 .

[18]  H. Arakawa,et al.  Photocatalytic decomposition of water and photocatalytic reduction of carbon dioxide over zirconia catalyst , 1993 .

[19]  N. Getoff,et al.  PRIMARY PRODUCTS OF LIQUID WATER PHOTOLYSIS AT 1236, 1470 AND 1849 Å , 1968, Berichte der Bunsengesellschaft für physikalische Chemie.

[20]  A. Corma,et al.  Base Catalysis for Fine Chemicals Production: Claisen-Schmidt Condensation on Zeolites and Hydrotalcites for the Production of Chalcones and Flavanones of Pharmaceutical Interest , 1995 .

[21]  T. Moore,et al.  Mimicking photosynthetic solar energy transduction. , 2001, Accounts of chemical research.

[22]  Allen J. Bard,et al.  Artificial Photosynthesis: Solar Splitting of Water to Hydrogen and Oxygen , 1995 .

[23]  Fabrizio Cavani,et al.  Hydrotalcite-type anionic clays: Preparation, properties and applications. , 1991 .

[24]  D. D. De Vos,et al.  Hydrotalcite-like anionic clays in catalytic organic reactions , 2001 .

[25]  Yuichi Ichihashi,et al.  Photocatalytic Reduction of CO2 with H2O on Titanium Oxides Anchored within Micropores of Zeolites: Effects of the Structure of the Active Sites and the Addition of Pt , 1997 .

[26]  G. Dey.  CHEMICAL REDUCTION OF CO2 TO DIFFERENT PRODUCTS DURING PHOTO CATALYTIC REACTION ON TIO2 UNDER DIVERSE CONDITIONS: AN OVERVIEW , 2007 .

[27]  L. Hammarström,et al.  Artificial photosynthesis and solar fuels. , 2009, Accounts of chemical research.

[28]  Shigeo Miyata.  Anion-Exchange Properties of Hydrotalcite-Like Compounds , 1983 .

[29]  A. Corma,et al.  Conversion of methane into C1 oxygenates by deep-UV photolysis on solid surfaces: influence of the nature of the solid and optimization of photolysis conditions. , 2012, Chemistry.

[30]  Somnath C. Roy,et al.  Toward solar fuels: photocatalytic conversion of carbon dioxide to hydrocarbons. , 2010, ACS nano.

[31]  Basicity and basic catalytic properties of zeolites , 1988 .

[32]  F. Kapteijn,et al.  Amino-based metal-organic frameworks as stable, highly active basic catalysts , 2009 .

[33]  Covadonga Pevida,et al.  CO2 capture by adsorption with nitrogen enriched carbons , 2007 .

[34]  K. Yoshino,et al.  Absolute absorption cross section measurements of in the wavelength region 163–200 nm and the temperature dependence , 2003 .