Mesoporous silica SBA15 modified with a hyperbranched polyester polyol as electrocatalytic support

VALERIA N. SUELDO OCCELLO; GRISELDA A. EIMER; VERONICA BRUNETTI

Conferencia; VI San Luis Conference on Surfaces, Interfaces and Catalysis; 2018

The novel physical and chemical properties and potential applications of hybrid materials obtained from the assembly and organization of organic and inorganic components have increased the interest on its design and synthesis.1 In this field, mesoporous inorganic silica-based matrices and polymers are effective building blocks for the development of materials and nanodevices with a hard skeleton and a more flexible coating. The mesoporous inorganic material SBA-15 presents a uniform hexagonal structure of pores of 4-9 nm diameter range and ~1 cm3/g volume and a large specific area (690-850 m2/g) and the inorganic surface can be modified with different functional groups and catalytically active species.2 These structural characteristics favor the access and the interaction with diverse molecules. The polyester polyol Boltorn®H30 is a hyperbranched polymer with 2,2-bis(hydroxymethyl)propionic acid branching units and 32 hydroxyl end-groups on the periphery that facilitate the interaction with other molecules through hydrogen bonds.3 In our group, SBA-15 was previously synthesized and modified with Boltorn®H30 by physisorption. This composite was characterized by specific surface area determination (BET), infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscope (SEM), solid-state nuclear magnetic resonance (NMR) spectroscopy, and X-ray diffraction (XRD). In this study, the electrocatalytic properties of a glassy carbon electrode (GCE) modified with copper electrodeposited on two different matrices, SBA-15 and SBA-15-Boltorn®H30, was assessed. The electrode was modified by immersion in a suspension of the mesoporous material for 24 h and a subsequent incubation in an aqueous solution of CuCl2 (50 mM). The Cu/SBA-15-Boltorn®H30/GCE electrode showed a catalytic activity for reduction of H2O2. This behaviour was not observed with the electrode modified with SBA-15. References 1.El Kadib, A., Katir, N., Bousmina, M., and Majoral, J. P. Dendrimer-silica hybrid mesoporous materials,New J. Chem., Vol. 36, No. 2, 241?255, 2012. 2.Zhao, D., Huo, Q., Feng, J., Chmelka, B. F., and Stucky, G. D. Nonionic triblock and star diblock copolymer and oligomeric surfactant syntheses of highly ordered, hydrothermally stable, mesoporous silica structures, J. Am. Chem. Soc., Vol. 120, No. 24, 6024?6036, 1998. 3.?agar, E. and ?igon, M. Aliphatic hyperbranched polyesters based on 2,2-bis(methylol)propionic acid ? Determination of structure, solution and bulk properties,Prog. Polym. Sci., Vol. 36, No. 1, 53?88, 2011.