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

CO and H-2 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 H-2 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 H-2, achieving CO evolution rate of 45 mmol m(-2) h(-1) (>75 % gas selectivity) and H-2 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 H-2. This work provides a promising method to produce highly pure H-2 together with CO from biomass.

Automated summary

In this study, a method for producing CO and H-2 from biomass via a divided photoelectrochemical cell at room temperature is proposed. Nitrogen doped tungsten trioxide is used as the photoanode to reform biopolyols to CO and H+, while platinum cathode reduces H+ to H-2. The method shows high rates and purity, and can be applied to a wide range of biopolyols.