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PP-I-41CORRECT INVESTIGATION OF THE CATALYTIC ACTIVITY ANDSIZE EFFECT IN METHANE OXIDATION OVER Pt/γ-Al 2 O 3CATALYSTSIlya Yu. Pakharukov 1,2 , Irene E. Beck 1,2 , Valerii I. Bukhtiyarov 1,2 ,Vladimir I. Zaikovsky 1 , Vladimir V. Kriventsov 1 , Valentin N. Parmon 1,21 Boreskov Institute of Catalysis SB RAS, pr. Lavrentieva 5, Novosibirsk, 630090,Russia, E-mail: ilyapakharukov@yandex.ru2 Novosibirsk State University, str. Pirogova 2, Novosibirsk, 630090, RussiaMethane catalytic deep oxidation attracts great attention due to economic andecological reasons. This process is essential in pollution control for both stationaryand mobile applications. Moreover the catalytic combustion of methane has beenextensively studied as an alternative to conventional thermal combustion.Structure sensitivity of certain types of reactions on supported metal catalysts is ofgreat interest in heterogeneous catalysis. The data about structural sensitivity ofconsidered oxidation processes on Pt – containing catalysts are still controversial inthe literature. Usually the catalytic activity is evaluated by conversion normalized toquantitative catalyst characteristic such as weight, number of active sites etc. Howeverthis approach is inaccurate because of absence of proportionality between these values.The specific reaction rate depends on temperature and component concentrations only,so it can be used as accurate measure of catalytic activity. The turnover frequency(TOF) changing as a function of particle size of active component is main criterion ofstructure sensitivity of reactions. Reaction rate measurements carried out underdifferential conditions are most precise. The flow- recirculation method allows to achievethe gradientless mode in laboratory reactor [1] .In this work, the sensitivity of methane oxidation turnover frequencies to Ptaverage particle size was studied over two series 0.7 wt.% Pt/γ-Al 2 O 3 catalysts. Ourgoal was to obtain more information on the structure sensitivity of this process bymeans of the modern flow-recirculation method.Transmission electron microscopy was used to characterize the Pt averageparticle size and dispersion. XAFS spectroscopy was used to study oxidation state ofthe supported Pt species.The correct comparison of catalytic activities allowed to detect considerableimpact of the Pt nanoparticle size on the TOF value. Data illustrating size sensitivityof methane deep oxidation are shown in Figure 1.293