The Impact of Ni Species Nature on Low‐Temperature CO 2 Methanation Over CeZrO x /Ni Catalysts

ABSTRACT The efficacy of hydrogen activation by Ni species is a critical determinant of the catalytic performance in CO 2 methanation. Herein, the nature of Ni species in CeZrO x /Ni was modulated by altering the calcination atmosphere. The CeZrO x /Ni─O demonstrated excellent low‐temperature methanation activity, achieving a CO 2 conversion of 94.3% at 225°C. This value is 5.8 times higher than that of the CeZrO x /Ni─N. The characterization results indicated that Ni species formed in oxygen‐containing atmospheres exhibited high dispersion, which facilitated the formation of Ni–MO x interfaces and thereby promoted the activation of CO 2 and H 2 . In contrast, under oxygen‐free conditions, Ni species formed a strong interaction with oxygen atoms from CeZrO x , which suppressed the activation of H 2 . In situ DRIFT spectra demonstrated that the reaction involved dual pathways, namely the formate pathway and the CO pathway. The abundant Ni–O–M interfaces substantially enhanced CO 2 adsorption and conversion to formate species, thereby establishing the formate pathway as dominant.