title: Factors controlling activity of zirconia-titania for photocatalytic oxidation of ethylene.
abstract: Small photocatalytic devices were developed to remove ethylene from closed plant growth units flown in space. The devices utilized sol-gel-derived catalyst pellets of zirconia-titania. This study was undertaken to understand the significance of different factors on the photocatalytic activity of the catalyst. Increasing reaction temperatures and decreasing humidity of the air significantly increased oxidation of ethylene. The quantity of ethylene oxidized per unit time increased linearly with increasing flow rates, and increasing concentrations of ethylene. Zirconia-titania pellet size and heel depth had little effect on oxidation of ethylene. Platinizing the zirconia-titania significantly increased ethylene oxidation. The catalyst was found to absorb large quantities of water when the humidity of the air stream was elevated and this greatly decreased catalytic activity.
authors.affiliation: University of Wisconsin-Madison 53706, USA.
authors.forename: T W
authors.initials: TW
authors.lastname: Tibbitts
authors.forename: K E
authors.initials: KE
authors.lastname: Cushman
authors.forename: X
authors.initials: X
authors.lastname: Fu
authors.forename: M A
authors.initials: MA
authors.lastname: Anderson
authors.forename: R J
authors.initials: RJ
authors.lastname: Bula
mesh_terms: D000389:Air Conditioning; D000392:Air Movements; D019149:Bioreactors; D002384:Catalysis; D004867:Equipment Design; D005030:Ethylenes / Q000737:chemistry*; D006813:Humidity; D010084:Oxidation-Reduction; D010316:Particle Size; D010777:Photochemistry; D010937:Plant Growth Regulators / Q000737:chemistry*; D013696:Temperature; D014025:Titanium / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry*
chemical_list: D005030:Ethylenes; D010937:Plant Growth Regulators; C009495:titanium dioxide; C036216:ethylene; D015040:Zirconium; D014025:Titanium; C028541:zirconium oxide