On the role of the atmosphere in the catalytic glycerol transformation over iridium-based catalysts

Here, we report the transformation of glycerol alkaline solutions in the presence of supported iridium catalysts under either reductive or inert atmosphere at 453 K. It was shown that under H2, the expected 1,2-PDO issued from hydrogenolysis of the triol was the main product while under He, lactic acid was formed predominantly via Cannizzaro rearrangement.

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► Iridium catalysts are efficient for glycerol hydrogenolysis
► 1,2-propanediol was obtained up to 76% selectivity under H2 atmosphere
► Lactic acid was prepared up to 83% selectivity under He atmosphere