COMPRISING BORIDE OF TYPICAL ELEMENT FOR REMOVAL OF NITROGEN OXIDES

摘要

PURPOSE: To obtain a highly durable catalyst which removes nitrogen oxides from an exhaust gas even in the copresence of oxygen by using a boride of a typical element having a specific structural formula. ;CONSTITUTION: A boride of a typical element boride expressed by the formula MaBb (M is a typical element such as the IIa group or the IIb group of the Periodic Table; B is boron; and (a) and (b) are integers of 0b/a13) as a catalyst for removing nitrogen oxides. This catalyst removes nitrogen oxides from an exhaust gas, and further removes the nitrogen oxides even from an oxygen-rich exhaust gas. Besides, the catalyst is highly durable. The pulverized MaBb (M is at least ≥1 kind of the typical element) can be used as such. The pulverized MaBb is obtained by directly boriding a metal M directly. In addition, the boride can be obtained by a liquid phase reaction using an alkoxide or an inorgnic salt with M or B.;COPYRIGHT: (C)1995,JPO