Carbon-coated microstructures have been prepared via carbonization of polymers, which have been deposited onto microstructured wafers. The amount of carbon deposited depends on the composition of the precursor monomer solution and on the presence of a template. The activity of the wafers after impregnation with ruthenium in the hydrogenation of acrolein is, among others, affected by the composition of the polymers and the time of the calcination step. Most likely, the number of functional groups at the carbon surface as well as the porosity are responsible for this behavior. The selectivity pattern in the hydrogenation of acrolein is similar to that of the acrolein hydrogenation using conventional Ru/C catalysts in a fixed-bed reactor. (C) 2003 Elsevier B.V. All rights reserved.