## 4 Conclusions  
For the first time, the effect of different cerium(III) precursors was reported in the synthesis of Ce-MCM-41 materials. Cerium incorporation into the MCM-41 framework led to long-range disordered materials, but the results obtained by several characterization techniques showed the influence of different anions in the microstructural properties and catalytic activity of Ce-MCM-Cl and Ce-MCM-NO\({}_{3}\). A mechanism for cerium incorporation in the MCM-41 structure was proposed, where [Ce(OH)\({}_{3}\)] species were hydrogen bonded to silicate anions, forming framework Ce-O-Si bonds during condensation. It was also observed that the synthesis of Ce-MCM-NO\({}_{3}\) follows a different path when compared to Ce-MCM-Cl. The former induced Ce(OH)\({}_{3}\) monomers to aggregate, forming non-framework CeO\({}_{2}\) during calcination on the MCM-41 surface, while the latter preferentially formed framework Ce-O-Si bonds. The preferential formation of CeO\({}_{2}\) species on Ce-MCM-NO\({}_{3}\) was attributed to the nitrate ions' strong binding to template molecules. The prepared materials were tested in the solvent free oxidation of benzyl alcohol to produce benzaldehyde, an important fine chemical compound for several industrial sectors, and the reaction parameters were optimized for each catalyst. Overall, Ce-MCM-Cl achieved better BzOH conversions and benzaldehyde (BzD) yields, while Ce-MCM-NO\({}_{3}\) offered increased BzD selectivity. The catalysts' reusability was also studied over three cycles. Ce-MCM-Cl and Ce-MCM-NO\({}_{3}\) showed a reduction in conversion, but increase in selectivity, resulting in negligible changes in BzD yield values. Also, it was observed that the different crystallization mechanism differentiates both catalysts' endurance towards deactivation, where Ce-MCM-NO\({}_{3}\) was more resistant than Ce-MCM-Cl. This effect was attributed to the CeO\({}_{2}\) coating on the Ce-MCM-NO\({}_{3}\) surface, making the latter less prone to possible etching effects from TBHP. Thus, the manuscript shows the importance of the selection of suitable heteroelement precursors in the synthesis of materials. Even more, there is scarce literature regarding differences in the same metal-incorporated silicas that can achieve different conditions for liquid-phase reactions, an aspect very important when seeking the best choices for the synthetic preparation of catalysts with the desired activity/selectivity in industrial processes. The following are available online at [[http://www.mdpi.com/2073-4344/9/4/377/s1](http://www.mdpi.com/2073-4344/9/4/377/s1)]([http://www.mdpi.com/2073-4344/9/4/377/s1](http://www.mdpi.com/2073-4344/9/4/377/s1)), Figure S1: XRD patterns of Ce-MCM-Cl and Ce-MCM-NO\({}_{3}\) materials at high angle region, Figure S2. Raman spectra of CTA\({}^{+}\) systems between 400-1700 cm\({}^{-1}\) (A) and 2800-3000 cm\({}^{-1}\) (B), Figure S3. Raman spectrum of crystalline CeO\({}_{2}\), Figure S4. Absorption spectra (A) and Davis-Mott plot (B) for of CeO\({}_{2}\), Figure S5. High magnification in HRTEM images highlighting CeO\({}_{2}\) 110 interplanar spacing for: Ce-MCM-Cl (A) and Ce-MCM-NO\({}_{3}\) (B), Table S1. Raman band assignments for CTA\({}^{+}\) cations in as-synthesized MCM-41 materials and template standards, Table S2. TGA results for the as-synthesized MCM-41 materials, Table S3. TGA results for the calcined MCM-41 materials. Conceptualization, formal analysis, methodology, project administration, visualization, writing--Review and editing, C.M.A. and J.L.M. ; investigation, C.M.A. and K.V.d.O. ; writing--Original draft preparation, C.M.A., K.V.d.O. and J.L.M. ; validation, C.M.A. ; funding acquisition, resources, supervision, J.L.M. This research was funded by Conselho Nacional de Desenvolvimento Cientifico e Tecnologico--Brasil (CNPq), grant number 308061/2015-2; Fundacao de Apoio a Pesquisa do Distrito Federal (FAPDF)--Brasil, grant number 0193001347/2016; and Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior--Brasil (CAPES), finance code 001.