There was little activity on metals with weaker carbon adsorption energies and stronger O 2 adsorption energies (see Supporting Information Figure ), so a smaller grid spanning carbon adsorption energies from -5.5 eV to -7.5 eV and oxygen adsorption energies from -3.25 eV to -5.25 eV was investigated. This smaller grid allows for a more refined mesh that still encompasses metals of interest, such as Pt and Rh, while trimming away the nonreactive metals. The volcano surfaces in Figures , and 8 show the best metal for synthesis gas yield is a metal with a carbon adsorption energy of ∆E C = -6.75 eV and an oxygen adsorption energy of ∆E O = -5.0 eV, which is closest to ruthenium. However, the optimal metal is located close to a steep volcano edge, where slight variations in carbon adsorption energies will cause a rapid decrease in activity. Partial oxidation products are favored as oxygen binds more strongly to the surface, as the adsorption energy of O(s) increases (becomes more negative), making it more difficult for oxygen to leave the surface. There is a plateau, or region with similar activity, at sightly weaker oxygen binding energies. CH 4 conversion follows a similar trend, but with a second high conversion peak occurring on a metal with C adsorption energies in between Pd and Pt, around -6.5 eV, and around an O adsorption energy of -3.5 eV at a C/O ratio = 0.8 to 1.3 (Figure ). This second 'peak' in conversion is due to the combination of both full and partial oxidation reactions and coincides with an inflection point between metals favoring full oxidation and partial oxidation. Synthesis gas yields decrease as full oxidation yield increases, showing full and partial oxidation pathways are directly in competition with each other.