Preparation and performance evaluation of a novel ethanol-enhanced Mn-modified carbon-based deNOx catalyst

Mn-modified carbon-based catalysts, with their extensive pore network and excellent redox activity, are gaining prominence for low-temperature deNOx applications. However, conventional preparation methods often suffer from the uneven dispersion of active MnOx species and a low proportion of highly active Mn4+, which limit deNOx's efficiency. To address these limitations, this study developed an efficient strategy for preparing low-temperature carbon-based deNOx catalysts by enhancing Mn modification through the use of ethanol as the impregnation solvent. The results indicated that, compared with deionized water, ethanol, with its lower polarity, surface tension, and better wettability, significantly enhanced the interaction between manganese nitrate and activated carbon during the impregnation process. This improvement facilitated better contact and penetration, promoted the uniform dispersion of MnOx on the activated carbon, and ultimately improved the performance of deNOx. Systematic process optimization identified 200 °C as the optimal calcination temperature and 8 wt% as the ideal Mn loading. Under a gas hourly space velocity of 20,000 h–1 and a deNOx temperature of 150 °C, the NO conversion reached 96.3% using the ethanol-impregnated catalyst, which was 13.4% higher than the 82.9% conversion achieved by the water-impregnated catalyst.