What if we could turn carbon dioxide, CO2, into a valuable resource? Using CO2 as a feedstock to create fuels or other chemicals would offer economic and environmental benefits. The challenge is designing effective processes that yield only the desired chemical: methane or carbon monoxide. Why? Scientists didn’t have a clear understanding of the pivotal steps in the reaction mechanism. Scientists at Pacific Northwest National Laboratory, led by Dr. Janos Szanyi, determined that formate (HCOO-), an oft-overlooked ion, was a critical intermediate in the overall CO2 conversion process. The balance in the rates of formate and carbon monoxide intermediates conversion determines what chemicals are produced.