*2.1. Catalysts Synthesis*

A silica mesoporous support (MCM-41) was synthesized following the procedure described by Ghedini et al. [24]. Hexadecyltrimethylammonium bromide (CTAB, Aldrich) was first dissolved in a NaOH aqueous solution at room temperature (r.t) under stirring; then, the required amount of tetraethyl orthosilicate (TEOS) was added. The resulting mixture was aged in an autoclave at 150 ◦C for 22 h, and thereafter filtrated, thoroughly washed and dried at room temperature. The surfactant was removed by calcination at 500 ◦C for 6 h in air flow (50 mL/min).

For the monometallic catalyst, the active phase was introduced on a silica support by incipient wetness impregnation using an aqueous solution of Co(NO3)2·6H2O in order to obtain 20 wt.% of metal loading.

For bimetallic samples, the precursors were introduced by co-impregnation of the previous Co solution and the corresponding precursors including (NH4)6Mo7O24.4H2O, MnSO4.H2O and Fe(NO3)3.9H2O) in order to obtain a nominal value of 10 wt% for each metal. Finally, the samples were dried and calcined at 500 ◦C in air flow (50 mL/min) for 6 h.

The catalysts were labelled: 20CoSiO2, 10Mo10CoSiO2, 10Mn10CoSiO<sup>2</sup> and 10Fe10CoSiO2.
