<p>Disclosed are solid titanium-free Fischer-Tropsch catalysts including iron homogeneously modified with a zirconium promoter/stabilizer. The homogeneously mixed solid catalysts can be formed through co-precipitation of iron and zirconium precursors followed by calcination and reduction to form the active catalyst materials. The catalysts can optionally include additional materials such as copper, potassium, and silicon promoters.</p>