Ammonia Carriers for Better Air Quality
Ammonia is one of the most powerful reductants to reduce nitrogen oxides (NOx) emissions. Vehicle exhausts are commonly treated with selective catalytic reduction (SCR) before the emission to achieve the acceptable NOx levels according to the emission standards. Therefore, a reliable and rapid ammonia carrier is of desire to enhance the NOx reduction performance.
Solid ammonia carriers, such as MgCl2 , CaCl2 , SrCl2 , demonstrate superior ammonia uptake capacity and good NOx conversion efficiency at low exhaust temperature, compared with traditional urea solutions. However, two main challenges from the solid ammonia carriers, namely low sorption kinetics and poor structural stability, can impede the development of SCR systems. Zhejian Cao and Farid Akhtar from our group have reported a porous SrCl2 structure scaffolded by graphene networks. The porous SrCl2-graphene composites can provide a rapid ammonia sorption-desorption and maintain the micro- and macrostructure after many sorption cycles (20 cycles have been verified in the lab).
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The cover: https://onlinelibrary.wiley.com/doi/10.1002/adfm.202170220
The article: https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.202008505