Titanium-incorporated organic–inorganic hybrid adsorbent for improved CO2 adsorption performance

The CO2 adsorption performance of acrylonitrile (AN)–tetraethylenepentamine (TEPA) adduct (hereafter referred to as TN) impregnated adsorbent was greatly enhanced by introduction of Titanium atom into the silica matrix. The adsorbents were characterized by X-ray fluorescence spectrometry (XRF), X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption/desorption, UV–vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy. The adsorption experiments together with the physicochemical characterization demonstrated that these adsorbents containing an optimal amount of Titanium (Ti/Si ≈ 0.1) remarkably reinforced the CO2 adsorption capacity and recycling stability. The highest CO2 uptakes reached 4.65 and 1.80 mmol CO2/g adsorbent at 25 °C under 90% CO2 (CO2/N2, 90:10 V/V) and 1% CO2 (CO2/N2, 1:99 V/V) conditions for sample Ti(0.1)-DMS-TN, respectively. Repeated adsorption/desorption cycles revealed that the Ti-incorporated adsorbent showed only a tiny decrease in adsorption capacity (1.778 mmol CO2/g adsorbent after 15 cycles, decreased by 0.95%), significantly enhanced the adsorbent recycling stability.