The synergistic effect of Pd NPs and UiO-66 for enhanced activity of carbon dioxide methanation

Carbon dioxide methanation is of great importance for both environment and energy because of the reduction of carbon dioxide emissions and the utilization of carbon source. In this work, UiO-66 was employed as the support for palladium nanoparticles via a sol-gel method to enhance the activity of CO 2 methanation. The physical-chemical properties of as-prepared catalysts were characterized using N 2 adsorption-desorption, X-ray diffraction (XRD), transmission electron microscope (TEM), temperature programmed desorption (TPD), temperature programmed reduction (TPR), thermo-gravimetric analysis (TGA), Fourier-transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). It was found that there was a synergistic effect between UiO-66 and supported Pd. CO 2 could be activated in UiO-66 via its Zr 6 O 4 (OH) 4 nods, while H 2 molecules were dissociated at Pd for further hydrogenation of activated CO 2 . As a result, the catalyst with a Pd loading of 6 wt.% exhibited a high activity with 56.0% of CO 2 conversion and 97.3% of CH 4 selectivity, corresponding to a STY of 856 g·h −1 ·kg cat −1 at 4 MPa and 340 °C.