Zeolite-like ion-exchanged Cu-attapulgite catalysts for promoted selective oxidation of ammonia†
Abstract
The selective catalytic oxidation of ammonia (NH3-SCO) to N2 and H2O is a highly efficient method for eliminating NH3 pollution. However, it is still a challenge to develop low-cost and high-performance catalysts. Herein, zeolite-like ion-exchanged Cu-attapulgite (Cu-ATP) catalysts have been originally developed for NH3-SCO, and the obtained Cu-ATP catalysts exhibit comparable NH3-SCO performance to the conventional Cu-zeolite catalysts. The dominant Cu2+ active sites in Cu-ATP facilitate the adsorption and activation of NH3 and O2, leading to high activity (T90 = 300 °C) and N2 selectivity (100%) over a wide temperature range from 180 °C to 390 °C. Temperature-programmed surface reaction and in situ diffuse reflectance infrared Fourier transform spectroscopy studies reveal that the NH3-SCO reaction at Cu2+ sites proceeds via the internal selective catalytic reaction (i-SCR) pathway, with NO2 serving as the key intermediate. This work paves the way for developing natural clay-based zeolite-like catalysts, which are expected to replace zeolite catalysts in various reactions.
- This article is part of the themed collections: Nanomaterials in air and Environmental Science: Nano Recent HOT Articles