140 / 2022-02-03 00:24:45

Granules of Zeolite - Strontium Chloride Composite for a Reliable Ammonia-based Selective Catalytic Reduction

ammonia,zeolite,SCR,deNOx,strontium chloride

Mineral Materials and Advanced Energy Materials > 9.Environment Functional Materials

Nitrogen oxides as one of the most harmful air pollutants have resulted in severe environmental problems. Therefore, the reduction of nitrogen oxides has been a long-time goal for achieving better air quality. Ammonia, as the most common reductant in selective catalytic reduction, faces several challenges in its storage on vehicles. Strontium chloride as a typical ammonia carrier shows slow ammonia sorption kinetics and poor structural stability. In this work, a zeolite - strontium chloride composite is designed and evaluated as ammonia carriers. The composite granules are achieved with two different approaches, chloride impregnation and freeze granulation. The zeolite - strontium chloride composite demonstrates a two-stage ammonia sorption: a rapid stage (0.24 mmol g^-1 min^-1) by the physisorption and a slow stage (0.07 mmol g^-1 min^-1) by the chemisorption. In addition, the mechanical performance of the granules by chloride impregnation maintains excellent after ammonia sorption cycles, offering a reliable structure of the designed composite.