Probe molecule studies: Active species in alcohol synthesis

The goal of this research is to develop a better understanding of the mechanisms of formation of alcohols and other oxygenates from syngas over supported catalysts. Different probe molecules are planned to add in situ during the reaction to help delineate reaction path ways and identify reaction intermediate species. The key of our study is to investigate how the species generated by these probe molecules interact with surface species present during oxygenate formation. CO hydrogenation reactions are being carried out in both the presence and the absence of the probe molecule under conditions which favor the formation of oxygenated products. A reaction and analysis system capable of carrying out the experiments for this study has been set up, modified, and tested. First, the commercially important Cu/ZnO/Al203 catalyst for methanol synthesis is being studied. Other catalysts, such as Pd and Rh with and without alkali or oxide promoters which are known to produce oxygenates from syngas, are being prepared and characterized for this study. Based on the observation of a previous study that nitromethane is an effective source of CH2 groups, it will be one of the primary probe molecules to be studied. In addition, acetylenic compounds are primary choices for this study also. These compounds were found by other workers to be effective as a source of chain initiators. 2 figs