Modulating nickel precursors to construct highly active Ni/Y2O3 catalysts for CO2 methanation

Constructing the interface of Ni/Y 2 O 3 heterogeneous catalyst is a feasible strategy for efficient catalyst design in CO 2 methanation, which can create the active Y–O–Ni interfacial sites by utilizing the interaction between Ni and Y 2 O 3 . In this work, the strategy of using different nickel precursors (nickel nitrate, nickel acetate, basic nickel carbonate and nickel citrate) was used to prepare various Ni-based catalysts supported on Y 2 O 3 , which were estimated for their catalytic performance on CO 2 methanation. The catalysts were characterized based on BET, XRD, TEM, H 2 -TPR, XPS and CO 2 -TPD, etc. The results indicated a close correlation between the metal dispersion and particle size of Ni/Y 2 O 3 catalysts and the nickel precursor employed. The Y–O–Ni interface structure in Ni/Y 2 O 3 catalysts, associated with basic sites, provides a richer source of basic sites, offering more active sites for CO 2 adsorption and activation. Ni/Y 2 O 3 catalyst prepared with nickel nitrate as the precursor exhibited characteristics such as a highly enhanced nickel dispersion, a smaller nickel particle size, and more abundant metallic Ni 0 sites. Moreover, nickel nitrate-derived Ni/Y 2 O 3 catalyst exhibited optimal catalytic activity, achieving a CO 2 conversion rate of up to 92 % at 300 °C, with 100 % selectivity to CH 4 , and displaying good stability over 30 h. Therefore, the dispersion of Ni and the size of Ni particles could be controlled by adjusting the precursor, which is closely associated with the catalytic activity of Ni/Y 2 O 3 catalyst. This work unveils the interface-property relationship of Ni/Y 2 O 3 catalysts and provides a new insight into strategy of constructing more effective Ni-based catalyst for CO 2 methanation through the controlled nickel precursor.