Paramelaconite‐Enriched Copper‐Based Material as an Efficient and Robust Catalyst for Electrochemical Carbon Dioxide Reduction

Abstract

A copper‐oxide‐based catalyst enriched with paramelaconite (Cu4O3) is presented and investigated as an electrocatalyst for facilitating electroreduction of CO2 to ethylene and other hydrocarbons. Cu4O3 is a member of the copper‐oxide family and possesses an intriguing mixed‐valance nature, incorporating an equal number of Cu+ and Cu2+ ions in its crystal structure. The material is synthesized using a solvothermal synthesis route and its structure is confirmed via powder X‐ray diffraction, transmission electron microscope based selected area electron diffraction, and X‐ray photoelectron spectroscopy. A flow reactor equipped with a gas diffusion electrode is utilized to test a copper‐based catalyst enriched with the Cu4O3 phase under CO2 reduction conditions. The Cu4O3‐rich catalyst (PrC) shows a Faradaic efficiency for ethylene over 40% at 400 mA cm−2. At −0.64 versus reversible hydrogen electrode, the highest C2+/C1 product ratio of 4.8 is achieved, with C2+ Faradaic efficiency over 61%. Additionally, the catalyst exhibits a stable performance for 24 h at a constant current density of 200 mA cm−2.

Electrochemical CO2 Reduction: Tailoring Catalyst Layers in Gas Diffusion Electrodes

“…Up to now, most reports on CO 2 gas diffusion electrolysis focus on the application of novel catalysts and their design, but not on the investigation of the basic assembly principles of the electrode that defines the catalytic environment and with it the reactivity of a particular catalyst. Along this line, GDEs, selective for CO/H 2 syngas mixtures, [ 24–29 ] formate [ 30–32 ] and C 2+ products [ 33–37 ] were investigated in gas diffusion setups. Especially the formation of C 2+ products like ethylene, ethanol, and n ‐propanol using copper‐based catalysts are herein of particular interest due to their use as feedstock's for carbon neutral polymers and fuels.…”

Controllable Synthesis of Leaf‐Like CuO Nanosheets for Selective CO2 Electroreduction to Ethylene

“…Compared to the C 1 products, only few kinds of catalysts have been reported to exhibit considerable selectivity to C 2 products, of which the copper‐based materials are the most attractive, especially for ethylene . Many pioneer researchers have studied the crystal structure effects of pristine copper towards CO 2 RR, where crystal planes, nanoparticle size and edge/corner morphologies are mostly discussed .…”

In situ energy-dispersive X-ray diffraction of local phase dynamics during solvothermal growth of Cu4O3

“…Therefore, we estimated the changes of Cu 4 O 3 , Cu 2 O and CuO from the fitted peak areas. Because these particles were spherical in shape [as observed by scanning electron microscopy (SEM) (Jiang et al, 2016)], were composed of smaller nanocrystallites [as observed by transmission electron microscopy (TEM) (Martić et al, 2019)] and settled freely in liquid, we believe the particles have no preferred orientation. Therefore, for the same species the peak area should be proportional to the total amount (or mass) of that species present within the gauge volume.…”

“…More recent studies have reported the observation of Cu 4 O 3 from thin-film methods (e.g. special forms of sputtering) ( Aryasomayajula, 2018) and wet chemistry methods that have special solvation environments (Zhao et al, 2012;Jiang et al, 2016;Toparli et al, 2017;Wang et al, 2018;Martić et al, 2019;Kociołek-Balawejder et al, 2019;Thanuja et al, 2019). Nevertheless, Cu 4 O 3 syntheses using the aforementioned approaches are all extremely sensitive to preparation conditions.…”

“…Other efforts have utilized the mixed-valence nature of Cu 4 O 3 in applications that involve electronic charge transfer (e.g. catalysis, batteries and antibacterial agents) (Zhao et al, 2012;Toparli et al, 2017;Wang et al, 2018;Kociołek-Balawejder et al, 2019;Thanuja et al, 2019;Martić et al, 2019). In most demonstrated applications, Cu 4 O 3 particles were presented as additives to the established formulations using either CuO or Cu 2 O.…”