Development of cerium-doped porous composite aerogel using cellulose nanocrystals for enhanced CO capture and conversion.

Reducing carbon dioxide (CO) levels in the atmosphere is crucial for combating global warming. One effective strategy involves using porous materials for the combined processes of CO capture and catalytic conversion. In this study, we developed composite aerogel materials using cellulose nanocrystals (CNCs) as templates, doped with cerium oxide, to enhance CO capture and conversion. The CNCs possess a high specific surface area, which helps maintain the aerogel's internal structure, preventing the collapse of the silica aerogel during high-temperature calcination. This stability promotes CO diffusion within the material, aiding in its reduction. Additionally, during high-temperature calcination, cerium nitrate decomposes into cerium oxide and nitrogen oxides, creating a network of micro-nano composite pores on the material's surface. The porous carbon materials exhibit excellent CO adsorption capabilities, which are attributed to their rich and well-organized pore structures along with the synergistic effects of metal oxides. Our tests demonstrated that these materials have a high CO adsorption capacity of 3.18 mmol/g and are capable of converting CO into carbon monoxide and methane through photocatalytic reactions. This research offers new approaches for developing materials that integrate CO capture with conversion processes.