Trabalho de catalisadores

Applied Catalysis A: General 413–414 (2012) 85–93

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Applied Catalysis A: General journal homepage: www.elsevier.com/locate/apcata

Study of La2−x Cax CuO4 perovskites for the low temperature water gas shift reaction
S.S. Maluf a , P.A.P. Nascente a , C.R.M. Afonso a , E.M. Assaf b,∗ a b

Universidade Federal de São Carlos, Departamento de Engenharia de Materiais, CEP 13565-905, São Carlos, SP, Brazil Universidade de São Paulo, Instituto de Química de São Carlos, CEP 13560-970, São Carlos, SP, Brazil

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The effects of small fractions of calcium (x = 0, 0.05, 0.1, 0.15, and 0.20) on the structure and the catalytic properties of La2−x Cax CuO4 peroviskites have been investigated. The samples have been synthesized using the co-precipitation method. Perovskite-type oxides were characterized by XRD, TPR, XPS, XANES, SEM, and TEM. Catalytic tests for the water gas shift reaction (WGSR) were carried out in a tubular reactor at 290 ◦ C. All samples showed a well-defined perovskite structure with surface areas between 6 and 18 m2 g−1 . The partial substitution of La by Ca enhanced the stability of the perovskites and increased their reduction temperature. All catalysts were actives for WGSR, and the best catalytic performance was obtained for the La1.85 Ca0.15 CuO4 catalyst, but the samples with 5 and 10% of Ca had the best TOF values for reaction. These results can be associated to promoter effect of calcium, the high surface area, and the reducible species Cu0 and Cu1+ . © 2011 Elsevier B.V. All rights reserved.

Article history: Received 8 July 2011 Received in revised form 27 October 2011 Accepted 28 October 2011 Available online 6 November 2011 Keywords: Water gas shift reaction Perovskites Catalysts

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