Emissions from stationary boilers contain nitrogen oxides (NOx), which cause photochemical smog and acid rain. In Japan, NOx contained in the gas emitted from large boilers is currently removed by denitration equipment. Current catalysts used in denitration systems require high reaction temperatures to remove NOx, which has hindered the free design of exhaust gas treatment systems.<\/p>\r\n\r\n\r\n\r\n
In collaboration with a company, our laboratory has been studying the development of a denitration catalyst that exhibits high activity at low temperatures. Previous denitration catalysts work at 300\u00b0C or higher, but the goal is to have high performance even at 100-150\u00b0C. At low reaction temperatures, the effect of moisture in combustion exhaust gas is very significant, and the presence of moisture has been a factor in reducing catalytic activity.<\/p>\r\n\r\n\r\n\r\n
We have already reported the world’s first use of vanadium pentoxide (V2<\/sub>O5<\/sub>) as a bulk catalyst for denitration. In our research to further improve the activity, we are developing a new catalyst by substituting tungsten for the metal backbone of the V2<\/sub>O5<\/sub> crystal. The reason for focusing on tungsten is that tungsten has the same elemental size as vanadium and is expected to stabilize the structure by linking V2<\/sub>O5<\/sub> three-dimensionally through the metal oxygen octahedral structure. The developed catalyst exhibited high activity even at reaction temperatures of 100 to 150\u00b0C and in the presence of moisture.<\/p>\r\n\r\n\r\n\r\n The development of an exhaust gas system using this catalyst will lead to lower catalyst costs and energy savings in NOx treatment in developed countries, including Japan, where NH3<\/sub>-SCR has already been introduced. In developing countries where air pollution is becoming more serious and exhaust gas treatment systems are not yet available, a low-temperature NH3<\/sub>-SCR system could be easily retrofitted to existing boilers. Since air pollution is an important and urgent environmental problem worldwide, the technology in this study has the potential to make a significant contribution to improving the air quality. As shown in this research example, we are conducting research on the development of a low-temperature denitration catalyst.<\/p>\r\n\r\n\r\n\r\n Introduction by EurekAlert! (2019)\uff1ahttps:\/\/www.eurekalert.org\/news-releases\/555626<\/a><\/mark><\/p>\r\n\r\n\r\n\r\n