The formation of ethylene oxide, the EC analogous to our PO, has previously been detected for perchlorate-containing lithium systems, although a different reaction mechanism was sodium carbonate, as well as the proposed precursor to PO. We chose this reaction as the initial step of the PO formation because the formation of sodium carbonate was previously found to be favorable 38 45 . While we did not detect any CO 3 within the GC measurements, Fig. shows that any formed carbonate would bind tightly to the metal surface, making it undetectable. At this point, the position of the methyl group, while irrelevant to the final product, may strongly influence the intermediate products. We, therefore, investigated the two possible methyl group placements in reactions a) and b), as visualized in Fig. .