Ni-modified mesoporous MCM-41 catalyzes the direct transformation of ethylene to propylene, the so-called ETP reaction, with conversion up to 68 % and propene selectivity up to 48 % [1]. Incorporation of aluminum into Ni-MCM-41 increases the catalytic activity [2], however, the role of aluminum, the reaction mechanism and nature of the active sites remains unknown [3].

Here, using a combination of surface organometallic chemistry and thermolytic precursor approach [4], we synthesized well-defined Ni(II) surface sites on silica-based supports (MCM-41 and Al-MCM-41) exploiting nickel siloxide (1) and aluminate (2, Scheme 1) molecular precursors. Their structure and reactivity towards ethylene will be discussed.

[1] M. Iwamoto, Y. Kosugi, J. Phys. Chem. C, 2007, 111, 13.
[2] L. Alvarado Perea, T. Wolff, P. Veit, L. Hilfert, F.T. Edelmann, C. Hamel, A. Seidel-Morgenstern, J. Catal., 2013, 305, 154.
[3] a) M. Iwamoto, Catal. Surv. Asia, 2008, 12, 28. b) M. Iwamoto, Molecules, 2011, 16, 7844. c) M. Iwamoto, Catal. Today, 2015, 242, 243.
[4] C. Copéret et al. Chem. Rev., 2016, 116, 323.