George A. Olah

A potentiometric method of monitoring methanol crossover through polymer electrolyte membranes of direct methanol fuel cells

Abstract Methanol crossover from the anode to the cathode through the polymer electrolyte membrane (PEM) has been one of the detrimental factors affecting the performance of direct methanol fuel cells (DMFCs). Extensive research work has been in progress for developing CH 3 OH crossover tolerant electrolyte membranes. The need for assessing CH 3 OH crossover by an easier and faster method than the conventional CO 2 analysis method has become significant. For this, a potentiometric method has been developed and tested using the Nafion membrane. By recording the potential ( E ) of a PtRu/C electrode in 0.2xa0M H 2 SO 4 supporting electrolyte during CH 3 OH crossover, it has been shown that the slope (d E /d t ), of E versus t (time) curve, is proportional to the crossover rate. From the time required to reach the equilibrium concentration of CH 3 OH on either side of the polymer electrolyte membrane, CH 3 OH crossover rate has been calculated. This method is expected to be useful in studying polymer electrolyte membranes and also in industry as a quality control technique. The method can also be used to sense methanol concentration.

Friedel-Crafts Reactions of Buckminsterfullerene

Abstract Buckminsterfullerene reects with aromatic benzene derivatives in the presence of Lewis acids such as aluminum trichloride or aluminum tribromide to give Friedel-Crafts fullerenation products. Polyhalogenated fullerenes also react with aromatic compounds to afford fullerylated aromatic compound under the Friedel-Crafts reaction conditions.

HPLC separation of hydrogenated derivatives of buckminsterfullerene

SummaryThe effect of composition and flow rate of the mobile phase on the HPLC separation of hydrogenated buckminsterfullerene (C60Hn n=2–38) was investigated on BuckySep column. Toluene was used as the basic solvent and hexane, heptane, cyclohexane, THF, acetonitrile, acetone, ethanol and 2-propanol as co-solvents. The fraction of co-solvents was varied 10–80%, and the flow rate 1–0.1 mL min−1. Toluene-acetonitrile 65∶35 and toluene-acetone 50∶50 provided the best separation. Under the best conditions complete separation of C60H2 and almost complete separation of the four most abundant isomers of C60H4 were achieved. Separation of derivatives with higher hydrogen content was very poor.