A catalyst composition comprising a cation and an anion of the formula Anq−Qpm+, wherein m, n, p, and q are positive integers, wherein m*p=n*q, wherein Qm+is an organo onium, and Aq−is an anion, provided that at least one Aq−is selected from the formula (I) wherein each R independently is H, halo, alkyl, aryl, aralkyl, or cycloalkyl, and which also may be halogenated, fluorinated, or perfluorinated, wherein two or more of R and R′ groups may together form a ring, wherein each R group independently may contain one or more heteroatom(s), wherein R′ can be the same as R, with the proviso that R′ cannot be halo, and wherein the catalyst composition is essentially free of hydrocarbon containing alcohol. Also provided are a fluoropolymer composition including this curative, a method of making a fluoropolymer, and fluoropolymer articles containing curable or cured fluoropolymer compositions.