275843 Porous Microsphere Composites of Silver/Ceria/Titania for Solar Fuel Production

Wednesday, October 31, 2012
Hall B (Convention Center )
Daniel Pitts and Ying Li, University of Wisconsin-Milwaukee, Milwaukee, WI

Photocatalytic conversion of carbon dioxide and water to fuels using low-cost and stable photocatalysts like titanium dioxide (TiO2) is a promising sustainable energy technology that not only reduces greenhouse gas emissions but also produces renewable fuels. However, the fast recombination of photo-induced electron-hole pairs results in a very low CO2 reduction efficiency. In this work, we have synthesized porous microsphere composites of nanocrystalline TiO2 modified with silver (Ag) and/or  ceria (CeO2). The TiO2 nanocrystals of anatase and anatase-brookite mixed phase as well as Ce-doped TiO2 were first fabricated by a hydrothermal method. Subsequently, Ag/TiO2 or Ag/Ce/TiO2 porous microspheres were synthesized through an ultrasonic spray pyrolysis (USP) process.  The photocatalytic activity of the prepared photocatalysts was tested in a photoreactor system under simulated sunlight irradiation.  It was demonstrated that synthetic gas or syngas, a mixture of hydrogen (H2) and carbon monoxide (CO) could be successfully produced from the photocatalytic conversion of CO2 and water in the presence of methanol as the hole scavenger.  The H2/CO ratio in the produced syngas was correlated with the photocatalyst properties.

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