Raw biomass electroreforming coupled to green hydrogen generation

Abstract

Despite the tremendous progress of coupling organic electrooxidation with hydrogen generation in a hybrid electrolysis, electroreforming of raw biomass coupled to green hydrogen generation has not been reported yet due to the rigid polymeric structures of raw biomass. Herein, we electrooxidize the most abundant natural amino biopolymer chitin to acetate with over 90% yield in hybrid electrolysis. The overall energy consumption of electrolysis can be reduced by 15% due to the thermodynamically and kinetically more favorable chitin oxidation over water oxidation. In obvious contrast to small organics as the anodic reactant, the abundance of chitin endows the new oxidation reaction excellent scalability. A solar-driven electroreforming of chitin and chitin-containing shrimp shell waste is coupled to safe green hydrogen production thanks to the liquid anodic product and suppression of oxygen evolution. Our work thus demonstrates a scalable and safe process for resource upcycling and green hydrogen production for a sustainable energy future.

A brief review of electrocatalytic reduction of CO2—Materials, reaction conditions, and devices

“…This system enables the high utilization of the electrons for both sides of the electrolyzer, and the reduced cell voltage. Beyond the MOR, various reductive substances such as urea, N 2 H 4 , glycerol, glucose, and chitin were used for anodic reactions to substitute the OER, but most of them were coupled with HER, and pairing the ECR with the chemical‐assisted anodic reactions will be a promising field for both of the fundamental study and the industrial applications 148‐152 Kinetics of the anode …”

“…On the other hand, although the standard electrode potentials of the chemical oxidation reactions are much lower than that of OER, the inevitable adsorption of oxygen species (‐O or ‐OH) on the electrode still needs higher potentials, causing large overpotentials. Ni‐based electrocatalysts can promote urea and alcohol oxidation reactions, but the active sites are identified as the Ni(OH) 2 /NiOOH redox species, which requires >1.3 V vs RHE to launch the oxidation 148‐152 …”

Ce‐Modified Ni(OH)2 Nanoflowers Supported on NiSe2 Octahedra Nanoparticles as High‐Efficient Oxygen Evolution Electrocatalyst

“…The polarization curve was recorded in O 2 ‐saturated 1 m KOH solution at a scan rate of 1 mV s −1 and the electrode potential was calibrated and converted to an RHE scale by using the equation of E (vs RHE) = E (vs Ag/AgCl) + 0.197 + 0.059 × pH according to previous method (Figure S33, see the section of Calibration of the reference electrode in the Supporting Information for details). [ 62–64 ] Moreover, Faradic efficiency was obtained by a gas chromatograph [GC‐2014] during the OER process.…”

Electroreforming of Biomass for Value-Added Products

“…Through applying a potential difference across two electrodes, chemical reactions can be driven, with oxidation occurring at the anode (positive electrode) and reduction at the cathode (negative electrode). Two types of desired products-valorized chemicals on the anode and hydrogen gas on the cathode-can be obtained via cellulose electroreforming [28]. Depolymerization and oxidation of cellulose at the anode can produce valuable chemical products, which could reduce reliance on traditional fossil fuel-based and resource-intensive methods of production.…”