Three-dimensionally ordered macroporous (3DOM) structure promoted the activity and H2O poisoning resistance of CeMn/3DOM-TiO2 catalyst in NH3-SCR

Abstract

NH3-SCR is an effective mean of NOx removal in the non-electric industry, however, the high activation temperature and poor H2O resistance of SCR catalysts posed a barrier to its application. In this work, a series of three-dimensionally ordered macroporous (3DOM) catalysts were synthesized via a colloidal crystal template (CCT) method, and various characterizations were carried out to explore the physicochemical property of catalysts. The experiment results reveal that Ce0.2Mn0.2/3DOM-TiO2 catalyst presents the excellent low-temperature catalytic activity of nearly 100% at 100 °C. Furthermore, the enhanced H2O resistance is achieved, certified by the unaffected NO remove at 150 °C in the participation of 15 vol% H2O. The characterizations results exhibit that the improved dispersion of the active component and enhanced redox ability are conducive to the low-temperature catalytic activity. N2 adsorption and desorption experiments indicate that catalyst with 3DOM support possesses a larger pore diameter and specific surface area, which may weaken the condensation of H2O in the microporosity of catalysts and improved the H2O resistance of the catalyst. In situ DRIFTS results manifest that Ce0.2Mn0.2/3DOM-TiO2 catalyst could not only absorb more NH3 and generate more surface-active sites, but inhibit the competitive adsorption between H2O and SCR reactants.