Described herein are catalysts and methods for converting waste biogas (e.g., a mixture of carbon dioxide and methane) into useful products. In some embodiments, the biogas is converted into a highly purified methane, that can be further processed to generate fuel products, including recycled natural gas (RNG) and liquid fuels. The described catalysts and methods may be advantageous over conventional methods, including by reducing catalyst costs, decreasing temperature requirements and/or providing higher purity products by reducing carbon dioxide and carbon monoxide in product streams.