Construction of Cerium-Doped Porous Composite Aerogel Templated by Cellulose Nanocrystals and its Integrated Performance of Co2 Capture and Conversion

Abstract

Reducing the concentration of carbon dioxide (CO2) in ambient air is critical to mitigating global warming. The integrated technology of capture and catalytic conversion based on porous materials is one of the important control methods. Here, we developed composite aerogel materials templated with cellulose nanocrystals (CNCs) and doped with cerium oxide for CO2 capture and conversion. CNCs has a high specific surface area and is able to maintain the internal structure of the aerogel, preventing the silica aerogel from collapsing during high-temperature calcination which promotes the diffusion of carbon dioxide within the materials and facilitates the reduction of carbon dioxide. At the same time, doping cerium nitrate can decompose into cerium oxide and nitrogen oxides during high temperature calcination, forming a good deal of micro-nano-composite pores on the surface of the materials. Porous carbon materials have excellent CO2 adsorption properties, while possessing high adsorption rates attributed to the rich and regular pore structure and the synergistic effect of metal oxides. Tests showed that our materials had high adsorption performance with an adsorption capacity of 3.18 mmol g-1 (0°C, 1bar), while our materials converted carbon dioxide into carbon monoxide and methane in a photocatalytic reaction. This work provides research ideas and methods for the preparation of adsorption-conversion materials for CO2 capture and conversion in an integrated manner.

Keywords: carbon dioxide adsorption, photocatalysis, incorporation, aerogel, Biochar