Study of the performance of nitrogen-doped modified activated carbon as catalyst carrier for the selective catalytic reduction of NO with NH3 at low temperatures

Abstract

Nitrogen-doped modified activated carbons (ACs) were prepared from coconut shell, date shell and almond shell using the urea modification method. NO tests of NH3 selective catalytic reduction (NH3-SCR) were conducted to evaluate the efficiency of different types of nitrogen-doped modified AC as denitration catalyst carriers between 50–220°C. Both AC and nitrogen-doped modified AC had catalytic effects on NO conversion; the nitrogen-doped modified AC had high denitrification activity in the low-temperature region, and NAC1-10 achieved an NO conversion rate of 65.7% at 50°C. The low-temperature denitrification activity of urea-modified AC was twice that of the untreated AC at all temperatures. The O2 concentration in the SCR reaction system had a significant effect on the NO conversion rate of the nitrogen-doped modified AC. As the O2 concentration increased from 0 to 1 vol%, the NO conversion rate increased rapidly from 22 to 65% and remained stable at 65%. A series of characterisation tools were used to determine the structure and physicochemical properties of the nitrogen-doped modified AC, including BET, XRD, elemental analysis, and FTIR. Nitrogen-doped AC showed good air velocity adaptability and low-temperature stability, suggesting that it is a promising carrier for NH3-SCR catalysts.