Sub-nanometer ceria-promoted Ni 13X zeolite catalyst for CO2 methanation

Sub-nanometer zeolite 13X-supported Ni-ceria catalysts were synthesized for CO2 methanation. XRD and SEM results show the structure and morphology of 13X zeolite after impregnation and calcination. Ce loading affected the catalysts' metal dispersion, reducibility, basicity and acidity, and thence their activity and selectivity. STEMEDX elemental mappings showed that Ce and Ni are predominantly highly dispersed. Ce has a positive effect on the reduction of NiO and leads to a relatively high number of medium basic sites with a low Ce loading. Highly stable 5%Ni2.5%Ce13X had high activity and nearly 100% CH4 selectivity in CO2 methanation at 360 ?C, which is mainly due to the high dispersion of metals and relatively high amount of medium basic sites. It can be inferred that this catalyst synthesis strategy has great potential for good catalyst dispersion, since metal uptake by the zeolite is selective for the metal citrate complexes in solution.

Automated summary

The research demonstrates that Ce and Ni are highly dispersed in the catalyst, with Ce having a positive effect on the reduction of NiO and leading to relatively more medium basic sites. The 5%Ni2.5%Ce13X catalyst shows high activity and CH4 selectivity, mainly due to the high dispersion of metals and relatively more medium basic sites.