Nitrogen oxide adsorption material, useful to clean exhaust gas, and remove harmful nitrogen oxide contained in diesel engine, comprises metal oxide containing metal element-A forming mono- or bivalent cation in oxide, and metal element-M

摘要

Low-temperature nitrogen oxide adsorption material comprises a metal oxide, where: the metal oxide contains a metal element-A, which forms monovalent or bivalent cation in the metal oxide, and a metal element -M; the value at the temperature conditions can be changed to = 150[deg] C in the presence of nitrogen oxides; the metal oxide exhibits a single phase crystal structure; the metal oxide pores exhibit an average pore diameter of 0.3-0.6 nm; the monovalent or bivalent cations of the metal element-A are present in the pores; and the average length of the pores is = 100 nm. Low-temperature nitrogen oxide adsorption material comprises a metal oxide, where: the metal oxide contains a metal element-A, which forms monovalent or bivalent cation in the metal oxide, and a metal element -M; the value at the temperature conditions can be changed to = 150[deg] C in the presence of nitrogen oxides; the metal oxide exhibits a single phase crystal structure; the metal oxide pores exhibit an average pore diameter of 0.3-0.6 nm; the monovalent or bivalent cations of the metal element-A are present in the pores; the content ratio of the metal element-A to the metal element-M is 0.11-0.19, when the metal element-A forms monovalent cations in the metal oxide; the content ratio of the metal element-A to the metal element-M is 0.055-0.095, when the metal element-A forms divalent cations in the metal oxide; and the average length of the pores is = 100 nm. Independent claims are included for: (1) producing the low-temperature nitrogen oxide adsorption material comprising either obtaining a mixture by physical mixing of a first compound and a second compound in a dry process, where the first compound contains the metal element-A, the second compound contains the metal element-M, obtaining the low-temperature nitrogen oxide adsorption material by altering the mixture at 60-140[deg] C for 1-8 hours and calcining the obtained mixture at 200-550[deg] C, or obtaining a powdered mixture by ball milling of a first compound and a second compound and obtaining the low-temperature nitrogen oxide adsorption material by calcining the powdered mixture at 200-550[deg] C; and (2) cleaning exhaust gas comprising contacting the nitrogen-containing exhaust gas with the low-temperature nitrogen oxide adsorption material to remove nitrogen.