Pacific Northwest National Laboratory (PNNL) has been conducting research for the United States Department of Energy, Energy Efficiency Renewable Energy, Biomass Program to investigate the feasibility of producing mixed alcohols from biomass-derived synthesis gas (syngas). This research has involved the screening of potential catalysts, and optimization of the more promising ones, using laboratory scale reactors. During 2009, the main goal of the testing program focused on optimizing selected supported catalysts containing rhodium (Rh) and manganese (Mn). Optimization involved examining different total concentrations and atomic ratios of Rh and Mn as well as that of the more promising promoters (Ir and Li) identified in the earlier screening studies. Evaluation of catalyst performance focused on attaining improvements with respect to the space-time-yield and converted carbon selectivity to C2+ oxygenates, with additional consideration given to the fraction of the oxygenates that were C2+ alcohols.