title: Methanol steam reforming promoted by molten salt-modified platinum on alumina catalysts.
abstract: We herein describe a straight forward procedure to increase the performance of platinum-on-alumina catalysts in methanol steam reforming by applying an alkali hydroxide coating according to the "solid catalyst with ionic liquid layer" (SCILL) approach. We demonstrate by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and temperature-programmed desorption (TPD) studies that potassium doping plays an important role in the catalyst activation. Moreover, the hygroscopic nature and the basicity of the salt modification contribute to the considerable enhancement in catalytic performance. During reaction, a partly liquid film of alkali hydroxides/carbonates forms on the catalyst/alumina surface, thus significantly enhancing the availability of water at the catalytically active sites. Too high catalyst pore fillings with salt introduce a considerable mass transfer barrier into the system as indicated by kinetic studies. Thus, the optimum interplay between beneficial catalyst modification and detrimental mass transfer effects had to be identified and was found on the applied platinum-on-alumina catalyst at KOH loadings around 7.5 mass%.
authors.affiliation: Lehrstuhl für Chemische Reaktionstechnik, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, 91058 Erlangen (Germany), Fax: (+49) 9131-8527421 www.crt.cbi.uni-erlangen.de.
authors.forename: Matthias
authors.initials: M
authors.lastname: Kusche
authors.forename: Friederike
authors.initials: F
authors.lastname: Agel
authors.forename: Nollaig
authors.initials: N
authors.lastname: Ní Bhriain
authors.forename: Andre
authors.initials: A
authors.lastname: Kaftan
authors.forename: Mathias
authors.initials: M
authors.lastname: Laurin
authors.forename: Jörg
authors.initials: J
authors.lastname: Libuda
authors.forename: Peter
authors.initials: P
authors.lastname: Wasserscheid
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D002248:Carbon Monoxide / Q000737:chemistry; D002254:Carbonates / Q000737:chemistry; D002384:Catalysis; D006878:Hydroxides / Q000737:chemistry; D007700:Kinetics; D000432:Methanol / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry*; D011188:Potassium / Q000737:chemistry; D017680:Potassium Compounds / Q000737:chemistry; D012492:Salts / Q000737:chemistry*; D013227:Steam; D014835:Volatilization
chemical_list: D002254:Carbonates; D006878:Hydroxides; D017680:Potassium Compounds; D012492:Salts; D013227:Steam; D010984:Platinum; D002248:Carbon Monoxide; C037593:potassium carbonate; D000537:Aluminum Oxide; D011188:Potassium; C029943:potassium hydroxide; D000432:Methanol
keywords: catalyst characterization; heterogeneous catalysis; methanol reforming; molten salts; platinum