DENITRATION CATALYST AND DENITRATION METHOD

摘要

PURPOSE:To provide a catalyst which has sufficiently high heat resistance at a high temperature and with which NOx in an exhaust gas of an internal combustion engine driven a low air-fuel ratio can be removed efficiently within a sufficiently short contacting period and provide denitration method with high NOx removing efficiency and high reliability. CONSTITUTION:A denitration catalyst is composed of an activated alumina having at least 120m<2>/g specific surface area measured by the nitrogen adsorption method, at least 0.60g/cm<3> bulk density measured by mercury compressing method, and at most 1.80g/cm<3> true density measured by mercury compressing method and silver carried on the activated alumina. A denitration catalyst coated structural body is an article composed of a supporting substrate of a refractory material having a large number of through holes and the denitration catalyst with which the inner surfaces of the through holes of the supporting substrate are coated and the coating ratio of the denitration catalyst per unit volume of the supporting substrate is 20-200g/L. Denitration method for an exhaust gas comprises bringing the catalyst or the structural body into contact with an exhaust gas of an internal combustion engine driven at a low air-fuel ratio at an inlet of a catalyst-containing layer at 450-600 deg.C exhaust gas temperature.