Storage and separation of methane and carbon dioxide using platinum- decorated activated carbons treated with ammonia

Activated carbon (AC) was treated with ammonia for nitrogen doping and then was further anchored with platinum nanoparticles through ultrasound-assisted impregnation method. Methane (CH4) and carbon dioxide (CO2) storage of the pristine and modified activated carbon were determined at ambient temperature. All the samples showed high storage capacities with preference towards carbon dioxide storage, which would be favorable for both energy and environmental applications. Ammonia treatment slightly improved the storage of both CH4 and CO2 for all the samples, which could be attributed to the little improvement in the micropore properties upon nitrogen doping. Platinum decoration had an opposite influence on both CH4 and CO2 storage, which might be due to the absence of metal encouraging storage mechanism such as gas dissociation or reconstruction on platinum's surface in addition to the harmful effect of metal pore-blocking and higher density of metal particles.