The present invention relates to catalysts, systems, and methods for producing products such as fuels and fuel additives from polyols. In an embodiment, the invention includes a method of producing a fuel additive, including combining a polyol and a component selected from the group consisting of alcohols and organic acids to form a reaction mixture and contacting the reaction mixture with a metal oxide catalyst at a temperature of greater than about 150 degrees Celsius. Other embodiments are also included herein.