A method of catalytic
ammonia decomposition, where the method includes: flowing
ammonia into a reactor charged with a supported medium entropy
metal alloy (MEA) catalyst including MEA particles supported on a support, the MEA particles including a first principal
metal, a second principal
metal, and a third principal metal, where each of the principal metals is independently selected without repetition from the group consisting of Co, Cr, Fe, Mn, Ni, Al, Cu, Zn, Ti, Zr, Mo, V, Ru, Rh, Pd, Ag, W, Re, Ir, Pt, Au, Ce, Y, Yb, Sn, Ga, In, and Be; and catalytically decomposing the
ammonia into
hydrogen and
nitrogen over the supported MEA catalyst in the reactor at a
reaction temperature between 200° C. and 900° C.