Salting‐Out Aldehyde from the Electrooxidation of Alcohols with 100 % Selectivity

Abstract

Selective electrocatalytic oxidation of alcohols to value‐added aldehydes has attracted increasing attention. However, due to its higher reactivity than alcohol, the aldehyde is easily over‐oxidized to acid in alkaline electrolytes. Herein we realize the selective electrooxidation of alcohol to aldehyde on NiO by tuning the local microenvironment to salt out the aldehyde from the reaction system. The origin of the high selectivity was found to be the inhibition of the hydration of aldehydes, which is the result of the decreased alkalinity and the increased cation and substrate concentration. This strategy could salt out the aldehyde at the gas|electrolyte interface from the electrooxidation of alcohol with 100 % selectivity and be easily extended to other selective oxidation reactions, such as 5‐hydroxymethyl furfural (HMF) to 2,5‐furandicarboxaldehyde (DFF) and amine to an imine.

Electroreforming injects a new life into solid waste

“…In light of this, it is extremely desirable to explore new strategies that enable selective production of DFF under alkaline conditions. Currently, some promising approaches, including the construction of a liquid–liquid–solid system and the introduction of the salting-out effect, have shown the selective transformation of benzyl alcohol into benzaldehyde in alkali, 253,254 which could be expected to extend to the DFF production. Except for DFF, there is no available literature study concerning electrochemical access to HMFCA, and HMFCA typically exists as an intermediate in FDCA synthesis.…”

Indirect Electrocatalysis S─N/S─S Bond Construction by Robust Polyoxometalate Based Foams

“…If the current is eliminated from the optimal conditions, the desired product is trace, which illustrates that the reaction could not proceed in the absence of the electric current. Besides, the intermediate 1,2-bis(benzo[d]thiazol-2-yl)disulfane can also be monitored by 1 H NMR test during the reaction process (Figure S19, Supporting Information). Preliminary results are consistent with previous studies, [24][25][26] suggesting that the formation of S─S bond as the homocoupling product is a key step in the catalytic cycle.…”

“…Electrocatalytic conversion, a sustainable synthetic strategy that can combine renewable electric energy, has attracted increasing DOI: 10.1002/adma.202304716 attention around the world. [1,2] Generally, the organic electro-synthesis methods can be basically classified as direct and indirect electrolysis techniques, in which the direct electrolysis involves with the direct contact of electrocatalysts with the electrode while the indirect one achieves through the electrocatalysis interaction in the electrolyte (i.e., dispersion or dissolving electrocatalysts in electrolyte via in-cell or excell processes). [3] In direct electrolysis, in the case of oxidation at an anode, electricity rather than a chemical oxidant drives electron transfer by shuttling electrons between the surface of electrode and organic substrates.…”

Single-Site Cu-Doped PdSn Wavy Nanowires for Highly Active, Stable, and CO-Tolerant Ethanol Oxidation Electrocatalysis

“…Among the various catalyst candidates toward alkaline EOR, Pd-based nanostructures have continued to receive many efforts in their development for alkaline EOR because of their relatively rich abundance and promising properties in alcohol electrooxidations. − However, pure Pd catalyst still faces the problems of unsatisfied activity and poor stability in EOR, because the toxic intermediates (e.g., CH 3 CO ads , CO ads , etc.) formed during EOR can quickly adsorb on the Pd surface, thus deactivating the catalyst.…”