from first principles PP-I-1

OP-III-24Catalytic Purification of Exhaust Gases over Pd-Rh Alloy Catalysts:From Mechanism Understanding to High Temperature StabilityVedyagin A.A. 1,2 , Gavrilov M.S. 1 , Volodin A.M. 1 , Stoyanovskii V.O. 1 ,Slavinskaya E.M. 1 , Mishakov I.V. 1,2 , Shubin Yu.V. 31 Boreskov Institute of Catalysis SB RAS, Novosibirsk, Russia2 Novosibirsk State Technical University, Novosibirsk, Russia3 Nikolaev Institute of Inorganic Chemistry SB RAS, Novosibirsk, Russiavedyagin@catalysis.ruReducing air pollution nowadays is of the utmost importance. It is known that the mobilepollution sources (primarily motor cars) are responsible for about 60 % of total carbonmonoxide releasing in the atmosphere. Exhaust gases normally contain volatile organiccompounds, CO, nitric oxides and unburned hydrocarbons in various concentrations whichare to be determined by the engine type. Gasoline engine exhausts can be converted toharmless nonpollutants via using heterogeneous three way catalysts (so-called TWC) in whichthe platinum group metals play the role of active component. The mechanism ofneutralization process is rather complicated and includes a large number of elementaryreactions proceeding at the same time. Understanding of mechanism is believed to beimportant for creation of new generation of high-performance and cost-effective catalysts.The principle problem of catalytic converters lies in their deactivation at the evaluatedtemperatures. As we reported earlier [1], the rhodium (responsible for NO x reduction) canreadily diffuse from a surface inside the bulk of support (Al 2 O 3 ) therefore initiating the phasetransformation of latter into α-Al 2 O 3 where Rh ions become irreversibly encapsulated. Thehigh-T treatment of disperse Pd particles (essential for oxidation of CO and hydrocarbons)results in their significant sintering that explains the loss of activity [2]. This work concernsdevelopment of stable bimetallic catalysts based on improved action of Rh-Pd alloys.Financial support by Russian Foundation for Basic Research (Grant 11-03-00668) isacknowledged with gratitude.References:[1] V.O. Stoyanovskii, A.A. Vedyagin, G.I. Aleshina, A.M. Volodin, A.S. Noskov, App. Catal. B 90(2009) 141.[2] A.A. Vedyagin, A.M. Volodin, V.O. Stoyanovskii, I.V. Mishakov, D.A. Medvedev, A.S. Noskov,App. Catal. B 103 (2011) 397.68