Description: Our basic approach is to use a photoelectrochemical cell operated under simulated Mars conditions. The light source will be solar simulator with a wide spectrum of emitted light. On Mars wavelengths of light down to 190 nm reach the surface (compared to Earth where only 300 nm and above reaches the surface). The soil will be the JSC.Mars 1 stimulant which is known to contain 10% TiO2 (in partial reduced forms) and is supposed to be a good analog for the surface soils on Mars. We will consider two possible sources of H2O: first water flowing as liquid from below the surface of the soil and second water deposited as condensate on the surface of the soil. Additional two types of photocatalysts will be evaluated for methane conversion efficiencies: off shelf low cost TiO2 (P25), and doped TiO2 nanostructures (nanotubes and nanowires) for broader solar wavelength absorptions.

Benefits: The proposed catalytical methane conversion uses nanomaterials for improved conversion efficiency. The success of the device application on Mars will substantially reduces the payload weight and mission costs. The proposed device is also applicable for terrestrial application in reducing the greenhouse gas emission and solar utilizations.

Fuel production for base power systems, local mobility, and launch for Earth return are key requirements for the exploration of Mars including sample return and human exploration. Methane has long been recognized as the fuel of choice for Mars in situ resource utilization (ISRU) due to its relatively high cryogenic temperature. However methane on Mars must be produced in situ from atmospheric CO2. We propose to demonstrate in a prototype device for the conversion of H2O and CO2 to CH4 using only sunlight and minerals (TiO2) already known to be present on Mars. Interestingly the mechanism we propose here may be responsible for natural methane production on Mars today and may therefore account for the curious methane observations recently reported.