1. National Renewable Energy Laboratory (NREL), 1617 Cole Blvd. Golden, Colorado 80401; Department of Chemical Engineering, Colorado School of Mines, Golden, Colorado 80401; Department of Chemistry, Roskilde University (RUC), DK-4000 Roskilde, Denmark; H. Lundbeck, DK-2500 Valby, Denmark; and Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44, 01-224 Warsaw, Poland