Unraveling the mechanism for paired electrocatalysis of organics with water as a feedstock

Abstract

Paired electroreduction and electrooxidation of organics with water as a feedstock to produce value-added chemicals is meaningful. A comprehensive understanding of reaction mechanism is critical for the catalyst design and relative area development. Here, we have systematically studied the mechanism of the paired electroreduction and electrooxidation of organics on Fe-Mo-based phosphide heterojunctions. It is shown that active H* species for organic electroreduction originate from water. As for organic electrooxidation, among various oxygen species (OH*, OOH*, and O*), OH* free radicals derived from the first step of water dissociation are identified as active species. Furthermore, explicit reaction pathways and their paired advantages are proposed based on theoretical calculations. The paired electrolyzer powered by a solar cell shows a low voltage of 1.594 V at 100 mA cm−2, faradaic efficiency of ≥99%, and remarkable cycle stability. This work provides a guide for sustainable synthesis of various value-added chemicals via paired electrocatalysis.

σ-Alkynyl Adsorption Enables Electrocatalytic Semihydrogenation of Terminal Alkynes with Easy-Reducible/Passivated Groups over Amorphous PdSx Nanocapsules

“…can be synthesized under a constant potential of −1.05 V over an enlarged PdS x ANCs cathode, demonstrating the potential utility of our method. Furthermore, using upgrading organic oxidation to replace the low-value oxygen evolution reaction is significant in improving the overall energy efficiency. − By adopting a divided PdS x ANCs||RuO 2 two-electrode electrolyzer, paired synthesis of 2b (92% Conv. and 95% Sel.)…”

Structure Engineering and Electronic Modulation of Transition Metal Interstitial Compounds for Electrocatalytic Water Splitting

“…The key is the match of organic reactions at the cathode and anode, including the reaction rate, the numbers of transfer electron, etc. Recently, we have practiced the paired electrocatalysis of the 5-HMF EOR and 4-nitrobenzyl alcohol (4-NBA) electroreduction reaction (ERR) (Figure a), given that both reactions involving six electron–proton transfers guarantee good matching . The theoretical results indicate that FeP–MoP undergoes the 4-NSBA path for 4-NBA ERR with an energy barrier of 0.22 eV, and FeP–NiMoP 2 adopts the 5-HMFCA path for 5-HMF EOR (0.66 eV), which are far below those for HER (0.52 eV) and OER (1.70 eV), respectively (Figure b,c).…”

Defect engineering of Ni3S2 nanosheets with highly active (110) facets toward efficient electrochemical biomass valorization

“…Electrocatalytic oxidation (ECO) has been regarded as an intriguingly green methodology owing to the low thermodynamic barriers, operational simplicity and mild reaction conditions. [9][10][11] Particularly, ECO can take place at ambient pressure and temperature, and the reaction rate and product selectivity can be facilely regulated by the applied potential/current density at the working electrode through the adjustment of electron energy. 12,13 In the case of ECO of BA, the much lower electrodynamic potential (0.48 V vs. RHE) manifests its favorable thermodynamics with respect to that of the oxygen evolution reaction (OER, 1.23 V vs. RHE).…”