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 CO 2 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.