摘要 |
Eliminating nitrogen oxides from vehicle exhaust fumes comprises a material of cryptomelan, hollandite, romanechite or todorkite microporous structure comprising MO6 octahedra containing an element (M) from group IIIB, IVB, VB, VIB, VIIB, VIII, IB, IIB and IIIA and a second element (B) from alkali(ne earth), rare earth, transition and group IIIA and IVA elements. |