TERNARY CATALYST FOR PURIFICATION OF EXHAUST GAS FROM GAS ENGINE AND METHOD FOR PURIFYING EXHAUST GAS FROM GAS ENGINE

摘要

PURPOSE: To reduce the amt. of noble metals required for a catalyst and to successively and surely purify the exhaust gas from a gas engine for a long time by incorporating catalytic particles having a low ratio of Rh to Pt and catalytic particles having a high ratio of Rh to Pt into the wash coating layer of a ternary catalyst. ;CONSTITUTION: The top of a honeycomb carrier is coated with a wash coating layer contg. Pt and Rh as active catalytic metals and Ce as a co-catalyst. At this time, catalysts different from each other in the concn. ratio of Rh to Pt are carried in the wash coating layer and the Pt, Rh and Ce contents are regulated to ≥1g, ≥0.2g and ≥5g, respectively, per 11 apparent volume of the honeycomb carrier. By the coexistence of the catalysts different from each other in the ratio of Rh to Pt, high methane conversion activity and NO reduction activity can be ensured for the resultant ternary catalyst and NO, CO and HC are stably removed at a high rate of removal for a long time.;COPYRIGHT: (C)1995,JPO