Objective New bipolar configurations of Rh/YSZ film catalyst of low current bypass were realised; for the first time a new bipolar configuration of 2nd generation (catalyst film in a monolith YSZ reactor with multiple channels) was realised by deposition of a RuO2 catalyst film which under model test conditions resulted in a 50% increase in the conversion at high open circuit conversion (35%);- An YSZ tube (length: 10 cm, ID: 3/4 in) with the outer area coated with two gold electrodes and the inner area totally covered by an Rh thin film deposited by sputtering at room temperature was tested in both laboratory and test rig apparatus. Significant enhancements in catalytic activity were shown in laboratory experiments, while no significant enhancement of the catalyst performance were found in test rig experiments due to high flow rates and presence of bypass phenomena;- Effectiveness of both anodic and cathodic polarization was demonstrated in presence of O2; in NO conversion by propene/O2 enhancement factors of up to 2.5 with good N2 selectivity (50-90% range) were obtained both in CSTR and in tubular reactor type experiments;- Current application with insignificant power consumption was shown to efficiently assist the recovery of lost catalytic activity of Rh/YSZ film catalysts with respect to reduction of NO by propylene in excess oxygen conditions by increasing the reduction rate of oxidized surface sites via weakening the rhodium-oxygen bond;- The applicability of the NEMCA effect was shown to be present for the first time in the presence of O2 in the feed. The promotional effect caused by NEMCA was more pronounced in feeds containing small O2 concentrations;- Rh films promoted with Na were shown to have significantly higher activity as compared to the unpromoted open circuit performance of the same Rh film, indicating for the first time the synergetic effect of Chemical and Electrochemical Promotion;- Methods for the deposition of robust electrodes on pelletized dispersed metal catalysts supported on solid electrolytes have been developed and techniques for the preparation of pellets made of highly dispersed catalysts on YSZ, TiO2(D) and CeO2(D) with two terminal electrodes were developed;- Catalysts modified by DIMSI effect (doped Rh/TiO2 and Rh/ZrO2) were shown to have superior selectivity characteristics in the reduction of NO by C3H6/O2 in the presence of H2O and SO2 in the feed and to SO2 resistant; the metal/dopant ratio was demonstrated as a critical parameter controlling the performance of the DIMSI-modified catalysts examined under realistic conditions;- Catalysts based on Pt/TiO2-Al2O3 were shown to combine a high selectivity in the reduction of NO to N2 and a wider range of reaction temperatures of maximum conversion of NO.Objectives and content The objective of this project is to develop selectively acting N0x catalysts in the presence of oxygen for auto exhaust after treatment. Although efficient catalytic devices exist today for reducing N0x for stoichiometric operated gasoline engines, no such devises are available for lean burn and diesel engines. The need for such catalysts is great, taking into consideration the fact that lean burn engines offer considerable, up to 15%, enhancement in fuel efficiency and that nitrogen oxides released to the environment cause severe environmental damage which is related to smog formation and acid rain. The proposed investigation will lead to the development of innovative catalysts for the reduction of N0x with hydrocarbons or C0 in the presence of excess oxygen. The development of the novel catalytic materials is based on the concepts of non-faradaic electrochemical modification of catalytic activity (NEMCA) and dopantinduced metal-support interactions (DIMSI). These phenomena are used to alter the surface potential and work function of catalytic surfaces which, in turn, alters significantly their chemisorptive and catalytic parameters in the desired direction. In the case of NEMCA or electrochemical promotion, the catalyst, in the form of a porous polycrystalline film, is supported on a solid electrolyte support, such as Y203-stabilized ZrO2 (YSZ), an o2 conductor, b"-AI203 or Nasicon, Na+ conductors, and others. By applying electrical current or potential (i2V) between the catalyst and a counter electrode one can induce dramatic and reversible changes in catalytic activity and selectivity. The phenomenon of DIMSI refers to alterations of the chemisorptive and catalytic properties of small metal crystallites dispersed on semiconductive carriers such as Ti0X doped with altervalent cations. Doping of the semiconductive carrier alters its electronic structure in a desired direction, depending on the valence and the concentration of the doping cations. As a result of an electronic interaction developing at the carrier-metal interface, the work function of surface metal atoms is changed, which, hl turn, results in significant changes in chemisorptive and catalytic properties. The catalytic systems upon which the NEMCA and DIMSI states will be induced and investigated under condition of N0X reduction are those of Rah, Pt and Pd in model catalysts consisting of metal films on YSZ, and supported metals, highly dispersed on YSZ, TiO2 and CeO2 doped with altervalent cations. The development of novel catalytic materials will be supported by fundamental investigations of the NEMCA and DIMSI states of the catalysts and their effects on intrinsic chemisorptive and kinetic parameters as well as on sulfur-resistance and hydrothermal stability. A number of advanced characterisation and probing techniques will be employed in the fundamental studies, which include FT-IR under reaction conditions and of suitable probe molecules, W-Vis-NIR diffuse reflectance spectroscopy, temperature programmed (TPD, TP0, TPR, TPSR) and isotopic labelling (SSITKA) techniques, XPS, measurement of work function and of heat of adsorption. Promising catalysts will be tested in bench scale units using gas mixtures resembling those of lean burn and diesel engines. Detailed kinetic studies will also be conducted, as well as durability studies with particular emphasis to sulfur tolerance and hydrothermal stability. Successful catalysts will undergo long-term durability tests in a diesel engine using fuels with sulfur content from 30 to 500 ppm. The consortium involves 5 academic and 2 industrial partners. The presence of a catalyst manufacturer and an automobile manufacturer in the consortium ensures efficient implementation of the technology which will be developed. Fields of science engineering and technologyenvironmental engineeringenergy and fuelsliquid fuelsnatural scienceschemical sciencesorganic chemistryhydrocarbonsengineering and technologymaterials engineeringcoating and filmsnatural scienceschemical sciencescatalysisnatural sciencesphysical sciencesopticsspectroscopy Programme(s) FP4-BRITE/EURAM 3 - Specific research and technological development programme in the field of industrial and materials technologies, 1994-1998 Topic(s) 0302 - Transports Call for proposal Data not available Funding Scheme CSC - Cost-sharing contracts Coordinator University of Patras EU contribution No data Address 26500 Patras Greece See on map Total cost No data Participants (5) Sort alphabetically Sort by EU Contribution Expand all Collapse all Ecole Polytechnique Fédérale de Lausanne Switzerland EU contribution No data Address 1015 Lausanne See on map Total cost No data JOHNSON MATTHEY PLC (TRADING AS SYNETIX) United Kingdom EU contribution No data Address Blounts Court, Sonning Common RG4 9NH READING See on map Total cost No data UNIVERSITA DEGLI STUDI DI MESSINA Italy EU contribution No data Address 1,Salita Sperone 31 98166 SANTAGATA MESSINA See on map Total cost No data University of Cambridge United Kingdom EU contribution No data Address Lensfield Road CB2 1EW Cambridge See on map Total cost No data Volkswagen AG Germany EU contribution No data Address 38440 Wolfsburg See on map Total cost No data
