A process to produce a supported chromium catalyst, the process comprising: (i) combining a chromium (III) compound with an activator-support comprising a solid oxide treated with an electron-withdrawing anion to form a mixture; and (ii) subjecting the mixture to an inert or reducing atmosphere at a peak temperature to produce the supported chromium catalyst, wherein: the chromium (III) compound comprises chromium (III) formate, chromium (III) acetate, chromium (III) propionate, chromium (III) butyrate, chromium (III) pentanoate, chromium (III) neopentanoate, chromium (III) hexanoate, chromium (III) 2-ethylhexanoate, chromium (III) benzoate, chromium (III) naphthenate, chromium (III) oleate, chromium (III) oxalate, chromium (III) acetylacetonate, chromium (III) stearate, chromium (III) laurate, or any combination thereof; and the activator-support comprises fluorided alumina, chlorided alumina, bromided alumina, sulfated alumina, fluorided silica-alumina, chlorided silica-alumina, bromided silica-alumina, sulfated silica-alumina, fluorided silica-zirconia, chlorided silica-zirconia, bromided silica-zirconia, sulfated silica-zirconia, fluorided silica-titania, fluorided silica-coated alumina, sulfated silica-coated alumina, phosphated silica-coated alumina, or any combination thereof. (i) combining a chromium (III) compound with an activator-support comprising a solid oxide treated with an electron-withdrawing anion to form a mixture; and (ii) subjecting the mixture to an inert or reducing atmosphere at a peak temperature to produce the supported chromium catalyst, wherein: the chromium (III) compound comprises chromium (III) formate, chromium (III) acetate, chromium (III) propionate, chromium (III) butyrate, chromium (III) pentanoate, chromium (III) neopentanoate, chromium (III) hexanoate, chromium (III) 2-ethylhexanoate, chromium (III) benzoate, chromium (III) naphthenate, chromium (III) oleate, chromium (III) oxalate, chromium (III) acetylacetonate, chromium (III) stearate, chromium (III) laurate, or any combination thereof; and the activator-support comprises fluorided alumina, chlorided alumina, bromided alumina, sulfated alumina, fluorided silica-alumina, chlorided silica-alumina, bromided silica-alumina, sulfated silica-alumina, fluorided silica-zirconia, chlorided silica-zirconia, bromided silica-zirconia, sulfated silica-zirconia, fluorided silica-titania, fluorided silica-coated alumina, sulfated silica-coated alumina, phosphated silica-coated alumina, or any combination thereof. the chromium (III) compound comprises chromium (III) formate, chromium (III) acetate, chromium (III) propionate, chromium (III) butyrate, chromium (III) pentanoate, chromium (III) neopentanoate, chromium (III) hexanoate, chromium (III) 2-ethylhexanoate, chromium (III) benzoate, chromium (III) naphthenate, chromium (III) oleate, chromium (III) oxalate, chromium (III) acetylacetonate, chromium (III) stearate, chromium (III) laurate, or any combination thereof; and the activator-support comprises fluorided alumina, chlorided alumina, bromided alumina, sulfated alumina, fluorided silica-alumina, chlorided silica-alumina, bromided silica-alumina, sulfated silica-alumina, fluorided silica-zirconia, chlorided silica-zirconia, bromided silica-zirconia, sulfated silica-zirconia, fluorided silica-titania, fluorided silica-coated alumina, sulfated silica-coated alumina, phosphated silica-coated alumina, or any combination thereof. <EOS>