Boosting CO2 methanation on ceria supported transition metal catalysts via chelation coupled wetness impregnation.

[Display omitted] The incipient wetness impregnation (IWI) method is widely used in the preparation of supported transition metal catalysts for its high throughput and cost-effective synthesis, yet suffers from poor metal-support interaction, restricting its further application at an industrial scale. Herein, a universal strategy of chelation coupled impregnation (CCI) is presented. The as-prepared Ni/CeO 2 (CCI) showed superior catalytic performance for CO 2 conversion (84.3%) and CH 4 selectivity (100%) under the experimental conditions (WGHSV = 24,000 mL g−1 h−1 and H 2 /CO 2 = 4:1) even at low temperatures (T = 275 °C). The surface characterization results confirmed that the agglomeration of metal active sites in Ni/CeO 2 (CCI) was restricted and more surface oxygen vacancies were generated on CeO 2. Further, the in-situ diffuse reflectance infrared Fourier transform spectroscopy (in-situ DRIFTS) analysis suggested that the surface oxygen vacancies that served as active sites could facilitate the direct dissociation of CO 2 more favorably than the associative route, thus significantly promoting CO 2 methanation activity. [ABSTRACT FROM AUTHOR]