Soaking up greenhouse gases
doi:10.1038/nindia.2011.139 Published online 29 September 2011
New research has shown that an inorganic compound containing boron, carbon and nitrogen could adsorb carbon dioxide (CO2) and methane (CH4) — two greenhouse gases (GHGs) that contribute to global warming. This graphene-like layered compound may open up novel ways to reduce the levels of greenhouse gases in the atmosphere.
The researchers designed an organic graphene-like layered structure called borocarbonitride (BCN). They compared the efficacy of five BCN samples, layered graphene samples and activated charcoal in adsorbing the GHGs. They calculated the total amount of gas adsorbed in grams per gram of adsorbing material.
The adsorption of gases onto graphene was significantly less than that of BCN and activated charcoal. BCN samples exhibited better adsorption than activated charcoal because of their high surface area.
BCN5 showed the highest uptake of the GHGs, adsorbing 64% of CO2 and 5–17% of CH4 at room temperature. The CH4 molecule adsorbed into the BCN plane was approximately 3% smaller than that adsorbed in graphene, which indicates stronger bonding with BCN than graphene. The gas molecules adsorbed onto BCN molecules through electrostatic interaction.
"Being the biggest air pollutants in the world, it is extremely important to find ways of adsorbing or sequestering methane and carbon dioxide," says lead researcher C. N. R. Rao.
- Kumar, N. et al. Remarkable uptake of CO2 and CH4 by graphene-like borocarbonitrides, BxCyNz. Chem. Sus. Chem. doi: 10.1002/cssc.201100197 (2011)