Cellulose Conversion with Tungstated-Alumina-Based Catalysts: Influence of the Presence of Platinum and Mechanistic Studies

The performances of platinum supported on tungstated alumina (Pt/AlW) in the hydrothermal conversion of cellulose at 190 °C under H2 pressure were evaluated and compared to that of Pt‐free tungstated alumina (AlW). We show that the presence of Pt significantly increased the extent of conversion and led to a different product distribution with the formation of acetol and propylene glycol as the main products and a global yield of up to 40 %. Based on previous reports, we propose the formation of pyruvaldehyde on the Lewis acid sites of the tungstated alumina as a key intermediate. Pyruvaldehyde can then be transformed to acetol and propylene glycol or lactic acid depending on the presence or absence of supported Pt. Support for platinum: The hydrothermal treatment of cellulose under H2 in the presence of tungstated alumina‐based catalysts (AlW) yields lactic acid or acetol and propylene glycol as the main products depending on the presence or absence of supported platinum.