For Pt7Ge2, the ΔECO values range from -2.62 to -2.09 eV, similar to those for Pt7, consistent with the observation that the high T desorption peaks for Ptn and PtnGem are similar. For Pt7Ge2C2, the ΔECO values are smaller, ranging from -1.93 eV to -1.75 eV. We might expect, therefore, that carrying out two C2D4 TPD experiments to deposit carbon before measuring CO TPD would result in a noticeable decrease in the CO desorption temperature, but as noted above, roughly ~2/3 rds of the PtnGem clusters remain carbon free after two C2D4 TPD runs. The reason that C2 addition causes a decrease in the CO affinity of Pt7Ge2 appears to be related to the fact that C2 addition stabilizes the cluster framework. For Pt7Ge2, a noticeable restructuring of the core was observed upon CO binding, stabilizing the CO-Pt7Ge2 complex and enhancing the CO binding strength, however, this restructuring was not observed for Pt7Ge2C2.