Facilely preparing highly dispersed Ni-based CO2 methanation catalysts via employing the amino-functionalized KCC-1 support

In this research, the highly dispersed Ni-based CO2 methanation catalyst was facilely prepared by using the amino-functionalized KCC-1 (AF-KCC-1) as support. In this system, the surface-grafted amino functional groups over the KCC-1 support could evidently intensify the surface basicity. The regioselective precipitation of the Ni2+ would occur around the amino functional group during the catalyst preparation process by the incipient impregnation method. Subsequently, the metallic Ni active sites could be highly dispersed on KCC-1 support after the H2 reduction. It was found that the 20Ni/AF-KCC-1 catalyst possessed better low-temperature activity and stability than the 20Ni/KCC-1 and 20Ni/SiO2 reference catalysts without amino-functionalization. These catalysts were systematically characterized by various techniques. The results revealed that the amino-functionalized 20Ni/AF-KCC-1 catalyst displayed much smaller metallic Ni active sites than the reference catalysts. Furthermore, the in-situ DRIFTS and online TPSR were employed to study the potential reaction pathways of CO2 methanation. The results demonstrated that the main reaction intermediates on the 20Ni/AF-KCC-1 catalyst greatly favored the formation of CH4. The amino-functionalized AF-KCC-1 supported Ni-based catalyst exhibited much better anti-sintering performance than the reference catalysts during the 40 h stability tests at 400 °C. Therefore, the amino-functionalized KCC-1 was proposed as the promising support for preparing the highly dispersed Ni-based CO2 methanation catalyst with a wide industrial application prospect.