**4. Conclusions**

MCM-41-supported Co and bimetallic Co-Mn, Co-Mo and Co-Fe catalysts were investigated regarding the aqueous phase transformation of glucose into biochemicals, operating under different reaction conditions. With increases in temperature and the number and strength of catalyst acid sites, the conversion of glucose increased, but resulted in a low carbon balance due to the formation of humins. Isomerization was the predominant reaction at lower temperatures, while humins prevailed at higher temperatures, longer reaction times and higher catalyst acidity. The synergy of Fe, Mn and Mo with the Co increased the activity at 150 and 200 ◦C, while 250 ◦C hydrothermal conditions favored the retro aldol condensation reaction of glucose and its intermediates (fructose, C4-C5 sugars and 5-HMF) to form humins. The best catalytic reactivity was obtained under mild reaction conditions with the weak acidic sites of the 10Fe10CoSiO<sup>2</sup> catalyst, yielding valuable biochemicals such as fructose, levulinic acid, ethanol and hydroxyacetone.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2227-9717/8/7/843/s1, Figure S1: XRD patterns of the 20CoSiO<sup>2</sup> (a), 10Fe10CoSiO<sup>2</sup> (b) 10Mn10CoSiO<sup>2</sup> (c) and 10Mo10CoSiO<sup>2</sup> (d) samples\*Co3O<sup>4</sup> ; ˆFe3O<sup>4</sup> ; MoO<sup>3</sup> ; #CoMoO<sup>4</sup> , Table S1: N<sup>2</sup> adsorption/desorption isotherms of catalysts and pristine support.

**Author Contributions:** Conceptualization, S.T.; methodology, D.P. and E.G.; validation, F.M., F.B. and D.G.; formal analysis and investigation, S.T., A.M. and A.F.; writing—original draft preparation, S.T.; supervision, M.S.; project administration, G.F.; funding acquisition, A.V. All authors were contributed in the manuscript writing. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by Italian National Research Program PRIN 2015 "Heterogeneous Robust catalysts to upgrade low value biomass stream (HERCULES)" project.

**Conflicts of Interest:** The authors declare no conflicts of interest.
