Photoelectrocatalytic Reforming of Polyol-based Biomass into CO and H2 over Nitrogen-doped WO3 with Built-in Electric Fields.

CO and H2 evolution from renewable and abundant biomass represent a sustainable way, but is challenged to be produced under mild conditions. Herein, we propose to produce CO and H2 from biomass via a divided photoelectrochemical (PEC) cell at room temperature. Nitrogen doped tungsten trioxide (N-WO3 ) photoanode reforms biopolyols to CO and H+ , and platinum cathode reduces H+ to H2 , achieving CO evolution rate of 45 mmol m-2  h-1 (>75 % gas selectivity) and H2 evolution rate of 237 mmol m-2  h-1 with purity >99.99 % from glycerol. The nitrogen doping induces structure polarity of WO3 photoanode, leading to the formation of an internal electric field which promotes the separation and transfer of the photoinduced charges and improves PEC efficiency. A wide range of biopolyols, such as ethylene glycol, xylose, fructose, glucose, sucrose, lactose, maltose, and inulin were effectively converted into CO and H2 . This work provides a promising method to produce highly pure H2 together with CO from biomass.