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

A new approach for the synthesis of zero-valent copper nanoparticles (CuNPs) 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 favor 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. OH-compounds 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.