Substrate engineering-enhanced low-temperature NOx and CO removal by Co1Mn2Ox@CuO/copper mesh monolithic catalyst.

This paper addresses the challenges of simultaneously removing nitrogen oxides (NOx) and carbon monoxide (CO) from industrial flue gas at low temperatures. A highly efficient Co1Mn2Ox@CuO/copper mesh (CM) monolithic catalyst with higher oxygen vacancies was developed by growing Cu(OH)2 nanorods in-situ on a copper mesh and subsequently synthesizing via a hydrothermal method. Experimental results show that the Co1Mn2Ox@CuO/CM catalyst can achieve 99.7 % NOx conversion and 99.4 % CO conversion at 160 °C, with strong resistance to H2O and SO2 and outstanding long-term stability. Characterization results demonstrated that the excellent catalytic performance can be ascribed to the presence of abundant high-valent Co3+, Mn4+, and Cu2+ species, an increased number of reducible species, more acidic sites, and a higher concentration of oxygen vacancies. The interaction between ammonia-based selective catalytic reduction (NH3-SCR) and CO oxidation reactions revealed that NH3 primarily inhibited CO oxidation, whereas CO had no significant inhibitory effect on NH3-SCR. Additionally, this study explored the factors contributing to the enhanced water resistance and the underlying mechanisms of both NH3-SCR and CO oxidation reactions using in-situ diffuse reflectance infrared transform spectroscopy (in-situ DRIFTS). In terms of application, computational fluid dynamics (CFD) simulations demonstrated that the copper mesh-based monolithic catalyst provided better heat distribution, preventing partial deactivation and contributed to the improvement of catalytic activity. This research provides an efficient solution for industrial flue gas treatment and highlights its potential for environmental applications.