Nanostructured Surface

Hydrogen oxidation with oxygen over 
supported nanoscale noble metal catalysts 
Boldyrieva O.Yu.1, Zaporozhetz O.A.1, Lisnyak V.V.1 
1 Faculty of Chemistry, Taras Shevchenko National University of Kyiv. Volodymyrska Str., 64, Kyiv-01601, Ukraine. 
E-mail: lisnyak@univ.kiev.ua

Supported noble metals are frequently used in catalysis. However, at preparing of oxidation catalysts by impregnation methods, we rarely get high-dispersed particles due to the lack of induced interaction between the noble metal salts as a precursor and the oxide support, which allows mobility of the precursor salt during drying. To overcome this limitation, catalysts containing ultra-dispersed nanosized metal particles were prepared by a specially elaborated convenient technique and were used in model catalytic reaction low temperature oxidation of hydrogen with oxygen. Experiments were conducted under the condition mimicking H2–air gas mixtures [1], stoichiometric H2–O2 gas mixture, and gas mixtures with the hydrogen excess. Such catalysts had sufficient surface area and pore volume to warrant such detailed consideration. The effective adsorption of H2 and O2 molecules was also observed and the nature of spillover and thermal hysteresis phenomena is disclosed. As a result of this study, a series of highly effective H2 oxidation catalysts has been developed. These materials are able to completely eliminate H2 from in H2–air mixtures even at zeroth temperatures in the best situation. XPS data point that the catalysts’ surface enriched in oxidized noble metals and also we found evidence that the interaction between metal particles and support depends on the chemical nature of support. These observations can give a base for the preparation of promising catalytic materials for H2 oxidation reaction with the potential application at fire prevention. As a final remark, we underline the high reactivity of catalytic system that based on non-inert to the reaction support and heterogeneous-homogeneous regime of the catalyst work. 

1.	Volovenko O.B., Zaporozhets O.A., Lisnyak V.V., Boldyrieva O.Yu. Platinum surface complexes as precursors for H2–O2 recombination catalysts. // Adsorption Sci Technol.-2017.-35.-P. 735-743.