Dopant- and Surfactant-Tuned Electrode–Electrolyte Interface Enabling Efficient Alkynol Semi-Hydrogenation

Abstract

Electrochemical alkynol semi-hydrogenation has emerged as a sustainable and environmentally benign route for the production of high-value alkenols, featuring water as the hydrogen source instead of H2. It is highly challenging to design the electrode–electrolyte interface with efficient electrocatalysts and their matched electrolytes to break the selectivity-activity stereotype. Here, boron-doped Pd catalysts (PdB) and surfactant-modified interface are proposed to enable the simultaneous increase in alkenol selectivity and alkynol conversion. Typically, compared to pure Pd and commercial Pd/C catalysts, the PdB catalyst achieves both higher turnover frequency (139.8 h–1) and specific selectivity (above 90%) for the semi-hydrogenation of 2-methyl-3-butyn-2-ol (MBY). Quaternary ammonium cationic surfactants that are employed as electrolyte additives are assembled at the electrified interface in response to applied bias potential, establishing an interfacial microenvironment that can facilitate alkynol transfer and hinder water transfer suitably. Eventually the hydrogen evolution reaction is inhibited and alkynol semi-hydrogenation is promoted, without inducing the decrease of alkenol selectivity. This work offers a distinct perspective on creating a suitable electrode–electrolyte interface for electrosynthesis.

Designed Nanomaterials for Electrocatalytic Organic Hydrogenation Using Water as the Hydrogen Source

“…Selective semihydrogenation of alkynes provides an important way to access fine chemicals and useful building blocks. , Typically, reducing the adsorption of alkene on the electrocatalyst surface and elevating the energy barrier of alkene over hydrogenation are two key aspects to ensuring a high alkene selectivity (Figure a). In these regards, the factors of good affinity to alkynes, excellent properties of hydrogen storage, and phosphorus (P)-modified nanomaterials demonstrating high activity toward HER , make P-modified Pd a potential candidate.…”

Cu Single‐Atom Catalysts for High‐Selectivity Electrocatalytic Acetylene Semihydrogenation

“…Selective hydrogenation of acetylene is a cost‐effective method to prepare polymer‐grade ethylene on a large scale [5,6] . Recently, researchers have found that utilizing water as a proton source and renewable electric energy makes it possible to selectively transform one‐carbon molecules and unsaturated hydrocarbons at standard temperature and pressure [7–10] . The electrochemical acetylene semihydrogenation process has been verified to be an alternative to the traditional thermal catalytic hydrogenation process [11–14] .…”

Boosting Hydrogen Peroxide Electrosynthesis via Modulating the Interfacial Hydrogen‐Bond Environment

“…[37][38][39] Dimethyl sulfoxide (DMSO), as a highly polar aprotic solvent, can modulate the hydrogen-bond environment of water, reducing the water dissociation activity and suppressing the hydrogen evolution reaction (HER). [3,29,31,40,41] It can be postulated that hydrogen-bond interactions between DMSO and water can alter the proton transfer ability of the PCET process, thus modulating the activity and selectivity of ORR.…”

“…The structure of the hydrogen‐bond network at the electrode‐electrolyte interface strongly affects the transport of water molecules from the bulk electrolyte to the interface, which is crucial for the formation and utilization of active H* species from water dissociation [37–39] . Dimethyl sulfoxide (DMSO), as a highly polar aprotic solvent, can modulate the hydrogen‐bond environment of water, reducing the water dissociation activity and suppressing the hydrogen evolution reaction (HER) [3, 29, 31, 40, 41] . It can be postulated that hydrogen‐bond interactions between DMSO and water can alter the proton transfer ability of the PCET process, thus modulating the activity and selectivity of ORR.…”