Structured Ni@NaA zeolite supported on silicon carbide foam catalysts for catalytic carbon dioxide methanation

Carbon dioxide (CO₂) conversion is an important yet challenging topic, which helps to address climate change challenge. Catalytic CO₂ methanation is one of the methods to convert CO₂, however, it is limited by kinetics. This work developed a structured Ni@NaA zeolite supported on silicon carbide (SiC) foam catalyst (i.e., Ni@NaA-SiC), which demonstrated an excellent performance with a CO₂ conversion of ~82%, being comparable to the corresponding equilibrium conversion, and CH₄ selectivity of ~95% at 400°C. The activation energy for CO₂ conversion over the 15Ni@NaA-SiC catalyst is about 31 kJ mol⁻¹, being significantly lower than that of the 15Ni@NaA pelletized catalyst (i.e., ~84 kJ mol⁻¹). Additionally, the structured catalyst was highly stable with sustained CO₂ conversion at 78.7 ± 1.4% and selectivity to CH₄ at 97.7 ± 0.2% over an 80 hr longevity test. In situ diffuse reflectance infrared Fourier transform spectroscopy-mass spectroscopy characterization revealed that catalysis over the structured catalyst proceeded primarily via the CO free mechanism.