Researchers studied the effects of a low-temperature, high-efficiency denitrification catalyst and process called fast SCR on NOx removal. They used an ammonia-based catalyst and found that fast SCR achieved nearly 100% denitrification efficiency at 180°C with a NO2/NOx ratio of 0.5. Different reaction conditions were tested, showing that moisture and oxygen levels affected the reaction. At higher temperatures, ammonia oxidation increased, leading to decreased denitrification efficiency and N2O production. The presence of SO2 in the gas mixture during fast SCR reactions maintained 100% denitrification efficiency up to 350°C.