A glass-fabricated microfluidic device was used to screen a series of homogeneous alkene hydrogenation reactions by using Wilkinson’s catalyst. Good to excellent conversions were achieved for a range of alkene substrates within short reaction times (<2 min) and low hydrogen pressures (<0.2 MPa). During the course of the screening procedure, a metallic Rh layer was found to build up on the channels of the microfluidic device. Further investigation of this layer revealed that it was a highly active catalyst for the hydrogenation of alkenes, enones, and alkynes. Furthermore, this Rh layer catalyzed the hydrogenation of toluene to methylcyclohexane.