from first principles PP-I-1

OP-IV-3Unravelling the Structure and Reactivity of Supported Ni Particlesin Ni-CeZrO 2 CatalystsBerlier G. 1 , Gopalakrishnan S. 1,2 , Miletto I. 1 , Coluccia S. 1,2 , Caputo G. 3 , Giaconia A. 3 , Sau S. 31 Università degli Studi di Torino, Department of Chemistry and NIS Centre of Excellence,Via P. Giuria n. 7, 10125, Torino, Italy2 ISTEC, Centro Nazionale delle Ricerche, Strada delle Cacce 73, 10135, Torino, Italy3 ENEA, “Casaccia” Research Center, via Anguillarese, 301, 00060 – Rome, Italygloria.berlier@unito.itThe growing request for the development and diffusion of technologies based on renewableenergy sources represents an important challenge for researchers working in catalysis. Whencoupled to water gas shift reaction, steam reforming of methane (MSR) can be employed toproduce hydromethane (a mixture of hydrogen and methane) after CO 2 removal. If thetemperature of the process is lowered by employing a proper catalyst, a low green-houseimpact fuel (which could be employed to power hybrid automotive systems) can be producedin solar powered plants, based on molten salt technology [1].One of the most promising catalysts for low temperature MSR is based on Ni-CeZrO 2 mixedoxide [2], where the CeZrO 2 support is supposed to play an important role in stabilizing theactive phase towards sintering and coke formation [3]. Thus, Ni-CeZrO 2 represents achallenging system for surface studies, due to the complex reactivity of both the support andthe supported active phase, with particular interest in their interaction.In this work, a one step co-precipitation/digestion method [2] was optimized to prepare aseries of Ni-Ce-ZrO 2 catalysts with various Ni loading and Ce/Zr ratios, high Specific SurfaceArea and good metal dispersion. The structural (XRD, HRTEM) and surface properties of thesamples were characterized (FTIR of adsorbed CO). Their reactivity and stability was testedin MSR reaction at 520 °C, varying steam to carbon ratio and spatial velocity, in order toobtain kinetic values for a possible upscale of the process. The results suggest goodperformances of the catalysts and an important effect of the support on the Ni phaseperformance.References:[1] A. Giaconia, M. De Falco, G. Caputo, R. Grena, P. Tarquini, L. Marrelli, AIChE J. 54 (2008)1932.[2] H. S. Roh, W.S. Dong, K.W. Jun and S.E.Park, Chem. Lett. 30 (2001) 88.[3] P. Kumar, Y. Sun, R. O. Idem, Energy & Fuels 21 (2007) 3113.79