Constructing active copper species in Cu-zeolites for coal-gas-SCR and elucidating the synergistic catalytic function of CuO and Cu2+ ion species†
Coal-gas-SCR, initially proposed in this work, is a low-cost and effective strategy to eliminate NOx emission in the iron and steel industry. In this work, the Cu-ZSM-5-IE+CP catalyst prepared by liquid ion exchange combined with coprecipitation was filtered out for NOx abatement with coke-oven gas (H2, CH4, and CO). By means of XRD, TEM, H2-TPR, EPR, UV-vis, XPS, etc., active centers of Cu-ZSM-5-IE+CP were studied. Combined with DFT calculations and ab initio thermodynamic (AIT) analyses, it was confirmed that highly dispersed CuO nanoparticles with the (111) planes exposed and [ZCuOH]/[Z2Cu] in the Z[Cu(II)]-6R-D4h structure are the most possible main active motifs for the coal-gas-SCR. Moreover, the synergistic effect of Cu2+ ions and CuO species was elucidated. In situ DRIFTS and SCR-TPD results revealed that surface species can migrate between CuO and Cu2+ ions, which could further accelerate intermediate species (NCO, CH3NO, and NH4+) formation, resulting in better deNOx efficiency.
- This article is part of the themed collection: Nanomaterials in air