Integrated SO2/NO2-containing CO2 capture and methane dry reforming over Ni-Ca dual functional material: A mechanistic study

Abstract

Integrated carbon capture and utilization (ICCU) has emerged as a promising strategy toward carbon neutrality. However, most existing studies rely on simulated flue gas compositions, neglecting the impact of common impurities such as sulfur oxides (SOx) and nitrogen oxides (NOx), thereby limiting the practical industrial applicability of ICCU technologies. Herein, we systematically investigate the effects of SO2 and NO2 at various concentrations on the adsorption-catalysis performance based on a representative Ni-Ca dual functional material (DFM) in ICCU-dry reforming of methane (ICCU-DRM) process. Exposure to 100 ppm SO2 showed negligible influence on catalytic activity but markedly inhibited carbon deposition. Further increasing the SO2 concentration to 500 ppm led to complete deactivation of the DFM. NO2 exhibited a similar concentration-dependent trend to SO2, albeit with a comparatively lower impact. Mechanistic analysis revealed that both SO2 and NO2 promote the formation of a coating layer of calcium-containing compounds on the surface of Ni nanoparticles, accounting for the part or total deactivation. These findings offer critical insights into the industrial applications of ICCU systems under realistic flue gas conditions.