from first principles PP-I-1

OP-III-13Heterogeneous Hydrogenation Reaction Mechanism Evaluationby Using ParahydrogenKovtunov K.V. 1,2 , Barskiy D.A. 1,2 , Zhivonitko V.V. 1,2 , Salnikov O.G. 1,2 ,Khudorozhkov A.K. 3 , Bukhtiyarov V.I. 3 , Koptyug I.V. 1,21 International Tomography Center SB RAS, Novosibirsk, Russia2 Novosibirsk State University, Novosibirsk, Russia3 Boreskov Institute of Catalysis SB RAS, Novosibirsk, Russiakovtunov@tomo.nsc.ruParahydrogen-induced polarization (PHIP) phenomenon has become one of the veryimportant tools for the investigation of homogeneous hydrogenation or hydrogen activationreactions mechanisms. The polarization providing by the using of parahydrogen in thecatalytic hydrogenation reaction is orders of magnitude higher than thermal one, therefore dueto the significant signal enhancement it is possible to study the fast reactions and identifyintermediates of the catalytic reaction even that presented in the low concentration in reactionsolution. Industrial catalytic processes are predominantly heterogeneous, and the studies ofthe nature of active sites and of the mechanisms of heterogeneous catalytic reactions representan extremely important area of research that could benefit from the utilization of PHIP effects.In this work it was shown that it is possible to observe PHIP effects in heterogeneoushydrogenation reactions catalyzed by immobilized as well as supported metal catalysts. ThePHIP effects were demonstrated for heterogeneous hydrogenation reactions carried out inboth liquid and gas phases. These results constitute the direct confirmation of the mechanismof the hydrogenation reaction [1]. The observation of PHIP indicates that hydrogen addition ispairwise. A plausible explanation of the experimental results relies on the concept of static ordynamic isolation or localization of catalytic sites by various adsorbates which partition themetal surface into smaller regions [2]. The resulting hyperpolarized fluids may besuccessfully utilized for gas phase MRI studies of microreactor loaded with the catalyst.This work was supported by the RFBR 11-03-93995-CSIC_a, RFBR 11-03-00248-а,12-03-00403-a, RAS (5.1.1), SB RAS (160, 61, 57, 122), NSh-2429.2012.3 and program ofthe Russian Government to support leading scientists (11.G34.31.0045).References:[1] K. V. Kovtunov, I. V. Koptyug, in Magnetic Resonanse Microscopy. (Eds. S. Codd, J.D. Seymour), Wiley-VC, Weinheim, 2008, pp. 101-115.[2] V. V. Zhivonitko, K. V. Kovtunov, I. E. Beck, A. B. Ayupov, V. I. Bukhtiyarov, I. V. Koptyug, J.Phys. Chem. C, 2011, 115 (27), 13386–1339156