Compounds comprising a hibonite structure and a method for their use

A compound having a formula AAl12-x-yMaxMbyO19, wherein:

• A is selected from Ca, Sr, Ba, Mg, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Li, Na, K, Rb, Cs, Pb, Bi or any combination thereof;
• Ma is selected from Ni, Fe, Cu, Cr, V, Mn, or Co or any combination thereof;
• Mb is selected from Ti, Sn, Ge, Si, Zr, Hf, Ga, In, Zn, Mg, Nb, Ta, Sb, Mo, W or Te or any combination thereof;
• x is from 0.01 to less than 12;
• y is from 0 to less than 12;
• x+y is less than 12;
• and
• if y is 0, then x is from 0.01 to less than 1;
• if Ma comprises Fe, then y is greater than 0, or Ma further comprises Ni, Cu, Cr, V, Mn, or Co or any combination thereof;
• and
• if Ma is Mn and Mb is Mg, then x+y is less than 1, or x+y is greater than 1.