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

Abstract

The site isolation strategy has been employed in thermal catalytic acetylene semihydrogenation to inhibit overhydrogenation and C−C coupling. However, there is a dearth of analogous investigations in electrocatalytic systems. In this work, density functional theory (DFT) simulations demonstrate that isolated Cu metal sites have higher energy barriers on overhydrogenation and C−C coupling. Following this result, we develop Cu single‐atom catalysts highly dispersed on nitrogen‐doped carbon matrix, which exhibit high ethylene selectivity (>80 % Faradaic efficiency for ethylene, <1 % Faradaic efficiency for C4, and no ethane) at high concentrations of acetylene. The superior performance observed in the electrocatalytic selective hydrogenation of acetylene can be attributed to the weak adsorption of ethylene intermediates and highly energy barriers on C−C coupling at isolated sites, as confirmed by both DFT calculations and experimental results. This study provides a comprehensive understanding of the isolated sites inhibiting the side reactions of electrocatalytic acetylene semihydrogenation.

Highly Selective Acetylene‐to‐Ethylene Electroreduction Over Cd‐Decorated Cu Catalyst with Efficiently Inhibited Carbon‐Carbon Coupling

“…Additionally, the C−C coupling side reaction was compared between the two models. There are three possible pathways for the coupling of two C 2 H 2 molecules to form C 4 H 6 [8b,10a, 26] . Figure 4e represents the most typical one involving the coupling of two vinyl (CH 2 CH*) adsorbates.…”

Copper Dispersed Covalent Organic Framework for Azide–Alkyne Cycloaddition and Fast Synthesis of Rufinamide in Water

“…Single‐atom copper catalysts (CuSACs) are receiving great attention because of their maximum atomic utilization and significantly improved activity. [ 19,25–34 ] For instance, Cao and coworkers synthesize a graphdiyne‐supported cuprous oxide nanocluster catalyst (Cu 2 O NCs/GDY) with stabilized Cu(I) in a low‐oxidation state without aggregation, so the addition of extra reductant is unnecessary. [ 19 ] Nevertheless, the reactions in the reported works have to be carried out in toxic acetonitrile or the mixture of acetonitrile and water and need a higher reaction temperature (over 60 °C) and a longer reaction time (6–24 h).…”

Hydrogen Spillover Accelerates Electrocatalytic Semi-hydrogenation of Acetylene in Membrane Electrode Assembly Reactor

“…In addition, this method offers advantages over traditional routes for ethylene production from petroleum and natural gas, as they integrate multiple reaction processes within milliseconds (at pilot scale), operate at atmospheric pressure, and exhibit other favorable characteristics. − Despite significant progress in thermocatalytic ASH, its high-temperature and high-pressure requirements result in increased energy consumption and environmental impacts such as nitrogen oxides, organic compounds, and waste heat generation . Additionally, the use of large amounts of hydrogen gas and subsequent separation processes add to the cost. − In contrast, electrocatalytic acetylene semi-hydrogenation (EASH) using water as the hydrogen source can be conducted at ambient conditions. , EASH offers lower temperature requirements, greener characteristics, reduced energy consumption, and simplified reactor design and enables scalable production . Therefore, EASH represents a promising and environmentally friendly approach to C 2 H 4 production …”