Defects modulating on MgAl-hydrotalcite nanosheet with improved performance in carbonyl sulfide elimination via a hydroxyl chemical looping route

Adsorption and dissociation of H2O along with the generated hydroxide ions (OH–) over catalyst plays key role in the carbonyl sulfur (COS) hydrolysis. Herein, we report a variety of magnesium aluminum layered double hydroxides nanosheet with abundant structural defects (MA-LDHs-SD-x) designed by a mechanochemistry method using white carbon black as the defects directing agent. The resulted MA-LDHs-SD-x possess abundant structural defects along with much enlarged BET surface area and pore volume (175 m2/g and 0.347 cm3/g vs 32 m2/g and 0.039 cm3/g), which provide enhanced amount of surface OH– base sites, tight and rigid diffusion channels for guest molecules. As expected, the MA-LDHs-SD-x were found to be rather active in catalyzing COS hydrolysis, nearly 100% conversion and selectivity can be achieved at only 30 °C without H2O in a span of 96 h through a hydroxyl chemical looping route, which showing potential application value in the industrial desulfuration.