Methods and systems for sequestering carbon dioxide and generating hydrogen are disclosed. In some embodiments, the methods include the following: dissolving an iron based material that includes a carbonate-forming element into a solution including the carbonate-forming element and iron; increasing a pH of the solution to cause precipitation of iron oxide from the solution thereby generating a first source of Fe2O3; reacting the carbonate-forming element in the solution with a first source of carbon dioxide to produce a carbonate thereby sequestering the carbon dioxide; oxidizing the first source of Fe2O3 with a carbonaceous fuel thereby generating a second source of carbon dioxide and iron; and oxidizing the iron with steam thereby generating hydrogen and an iron oxide. Some embodiments include producing iron-based catalysts.