Selective hydrogenolysis of glycerol to propanol is a sustainable reaction, which can play a critical role in the future of the propylene market, as one step dehydration of this sustainable propanol provides access to sustainable propylene. In this work, Copper (Cu) -Tungstosilicic acid (HSiW) catalysts were studied for the hydrogenolysis of glycerol. For the first time over a Cu catalyst, this study reports a yield of ~76 % for direct conversion of glycerol to propanols in continuous flow mode. Several advanced characterization techniques were employed to study the fresh and used catalysts. The presence of intact Keggin units of HSiW solid acid (with medium acidity) in the vicinity of small clusters of copper sites improved the performance and lifetime of these bifunctional catalysts. This study offers insights into the nature of the active sites required for the hydrogenolysis reaction, which was achieved without using expensive PGMs.