Ultra-low voltage bipolar hydrogen production from biomass-derived aldehydes and water in membrane-less electrolyzers

Abstract

Water electrolysis using renewable energy inputs is being actively pursued as a green route for hydrogen production. However, it is limited by the high energy consumption due to the sluggish...

Stabilization of alkaline 5-HMF electrolytes via Cannizzaro reaction for the electrochemical oxidation to FDCA

“…Recently, it was demonstrated that electrochemical furfural oxidation competes with the solution phase Cannizzaro reaction, which is the base-mediated disproportionation of aldehydes to their carboxylic acids and alcohols. 39,40 Similarly, we suggest the Cannizzaro reaction as the decisive degradation step for HMF in alkaline media, 41 with further implications for process optimization. The products of this reaction, dihydroxymethylfuran (DHMF) and 5-hydroxymethyl-2-furancarboxylic acid (HMFCA), can be electrooxidized to FDCA as well and allow almost quantitative conversion of the starting HMF.…”

Recent progress of Cu-based electrocatalysts for upgrading biomass-derived furanic compounds

“…Recently, Liu et al explored the uniqueness of Cu in the electrocatalytic oxidative dehydrogenation (EOD) of aldehydes. 94 They uncovered competing reaction pathways between EOD and non-electrochemical Cannizzaro reaction, which shared a common gem-diol intermediate and exhibited a strong potential dependence. The EOD could involve the adsorption of this diol species on the electrode surface, followed by C–H bond cleavage to produce H 2 .…”

An acid-alkaline furfural hybrid battery for furoate and bipolar hydrogen production

“…9 However, Pt suffers from severe *CO poisoning given its strong adsorption of *CO (with a binding energy of À1.63 eV, significantly higher than that of *CO on Cu, i.e., À0.63 eV), 9,11 which often leads to a high potential for Pt in order to observe a significant furfural oxidation current (B0.9 V vs. RHE). 9 In this regard, combining Pt and Cu might synergistically enhance the catalytic activity of Cu and the durability of Pt. 12 Given this, we developed a Pt-doped Cu (Pt-Cu) catalyst for furfural oxidation reaction (FOR).…”

“…Due to the synergistic effect between Pt and Cu, the Pt-Cu catalyst displays an impressive FOR activity with a low potential of only 0.076 V vs. reversible hydrogen electrode (RHE) at 100 mA cm À2 , much superior to the pure Cu catalyst and other recently reported catalysts. [7][8][9][10]13,14 We further designed an acid-alkaline furfural battery that couples alkaline FOR and the acidic hydrogen evolution reaction (HER) to simultaneously generate H 2 from both the anode and cathode, as well as furoate and electricity by effectively utilizing electrochemical neutralization energy (eqn (2), R 0 represents the furan ring), which can provide an extra potential gap of 0.828 V with the consumption of only acid and base (H + + OH À -H 2 O, DG = À79.9 kJ mol À1 ). 15 Notably, the waste acid and base are common in industry and thus can be utilized in this application.…”

“…The activity of the Pt-Cu catalyst is also superior to or at least comparable to recently reported catalysts (Table S1, ESI †). [7][8][9][10]13,14 To evaluate the effect of specific surface area, we also calculated the electrochemically active surface area (ECSA) by estimating the double-layer capacitance. 18 The result indicates that although the ECSA of the Pt-Cu catalyst is slightly higher than that of the Cu catalyst (1215 vs. 1055 cm 2 , Fig.…”