Syngas-Promoted Selective Catalytic Hydrogenolysis of Cellulose into C6-Ketones

Selective hydrogenolysis of cellulose into C 6 -ketones offers a promising route for the production of high-value carbonyl compounds. However, conventional metal-catalyzed hydrogenolysis methods typically rely on externally added acids and require high-purity H 2 . Herein, we report an alternative syngas-promoted hydrogenolysis method that eliminates these dual dependencies while enabling the selective transformation of cellulose into value-added C 6 -ketones. Under optimal conditions, using a commercial Pd/C catalyst at 230 °C and 3.0 MPa total pressure (H 2 /CO = 1.5/1.5 MPa) for 2 h, the yield of C 6 -ketones reached 37.8 C-mol%, representing a 6.8-fold enhancement compared to that obtained under pure H 2 . Mechanistic studies demonstrated a dual promotional effect of CO in directing cellulose to C 6 -ketones. First, competitive adsorption of CO on Pd active sites suppresses excessive hydrogenation and undesired hydrogenolysis of cellulose-derived intermediates. Second, CO participates in the water–gas shift (WGS) reaction (CO + H 2 O ⇌ CO 2 + H 2 ), generating carbonic acid (H 2 CO 3 ) in-situ via CO 2 + H 2 O ⇌ H 2 CO 3 , which provides a controllable acidic environment that promotes key intermediate transformations associated with C 6 -ketone precursor formation.