Synthesis, characterization and high temperature CO2 capture capacity of nanoscale Ca-based layered double hydroxides via reverse microemulsion

Abstract In this study, we report a reverse microemulsion method to prepare stable homogeneous suspensions containing dispersed Ca–Al layered double hydroxide (LDH) nanoparticles. By changing the concentration, reaction time and temperature, the nano-particles with different structural morphology was developed from amorphous aggregation to platelet, regular hexagon and hydrangea-like hierarchical structure. The crystallization and growth of Ca–Al LDH nanoparticles were involved with a nucleation and growth process under nonaqueous polar solvent/surfactant system. After calcination at 700 °C, the calcined nano-sized Cal–Al LDH powders synthesized from the reverse microemulsion display remarkable CO 2 capture behavior at 600 °C, which is strongly dependent on the reaction conditions (concentration, time and temperature). The calcined powder synthesized at 80 °C exhibits a faster rate of CO 2 absorption and higher CO 2 capture capacity of 44 wt% CO 2 without apparent degradation under multiple cycles of carbonation–calcination.