Effect of copper dispersion on SBA-15 and SBA-16 affinity towards carbon dioxide—an approach through thermal programmed desorption

Abstract

A new approach for the synthesis of zero-valent copper nanoparticles (CuNP) supported on ordered mesoporous silica SBA-15 and SBA-16 by using vegetal antioxidants, coffee Robusta and green tea was developed in the present work. Diverse characterization techniques such as X-ray diffraction, nitrogen adsorption-desorption, transmission electron microscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, and thermal programmed desorption of CO2 and water allowed stating that the appreciable specific surface area and porosity favored CuNP formation.Copper-loaded SBA-15 and SBA-16 exhibited higher surface basicity and hydrophilic character according to the type of the source of reducing agents and silica framework, respectively. OHcompounds interactions with both CuNP and SBA surface and more particularly with available Si-O-Si groups were found to promote metal dispersion reducing the particle size. The results obtained herein open promising prospects for designing low cost and "green" silica-based materials with judiciously tailored basicity and hydrophilic character for catalysis, adsorption and other surface processes.

TEOS Silane Film Modified with SBA-15 Loaded with Cocoa Husk Extract as Pretreatment of ASTM 1008 Steel

“…EXSBA has another thermal event by DTG (Figure 5B), the second event occurs in the temperature range of 150 °C to 550 °C, with a mass loss of 7.4% which can be attributed to the degradation of high molecular weight organic components with possible inhibitory properties impregnated in the mesopores and micropores of EXSBA, such as: hemicellulose, cellulose, lignin, fatty acids and tannins 42,44 . Finally, an inorganic thermal behavior of mass loss is observed 44,45 . Thus, the total mass loss of EXSBA was about 14.2%, indicating that at least about 7.4% can be attributed to the presence of organic compounds within the pores of EXSBA.…”

“…Therefore, the present work can also associate the mass loss in this first stage with the volatilization of these low molecular weight organic compounds that may be incorporated into EXSBA due to the loading with cocoa husk extract. The curve of SBA (Figure 5A) maintains the inorganic characteristic of thermal stability up to 800 °C, with a mass loss of 1.5% that can be attributed to the dehydroxylation of the mesoporous silica 45 . Therefore, there was a total mass loss of 10% for pure SBA-15.…”