Electrochemical Reduction of Carbon Dioxide on Zinc-Modified Copper Electrodes

Abstract

Electrochemical reduction of carbon dioxide (CO 2 ) was performed on zinc-deposited copper (Cu/Zn) electrodes, and the faradaic efficiency of this system toward methane, ethane, and hydrogen was evaluated. Hierarchically structured Zn was electrodeposited on a Cu substrate under constant voltage in a varying bath concentration of Zn to yield low-and high-concentration deposits, represented as Cu/Zn-A and Cu/Zn-B, respectively. The prepared materials were characterized by X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. The reduction of CO 2 was performed with the Cu/Zn electrodes in an H-type cell, and the results obtained were compared with those from bare Cu and Zn electrodes, revealing that a high deposit of Zn on Cu (Cu/Zn-B) shows greater conversion efficiency than does a low Zn deposit (Cu/Zn-A) and the maximum faradaic efficiency of methane follows the order Cu/Zn-B (52%) > Cu (23%) > Zn (7%). Moreover, the efficiency of hydrogen formation is suppressed on Cu/Zn-B (8%) compared to bare Cu (68%) in the potential range studied. The results suggest that depositing Zn on Cu favors a protonation reaction, which results in higher C 1 product formation on a Cu/Zn-B electrode.

Copper and Copper‐Based Bimetallic Catalysts for Carbon Dioxide Electroreduction

“…Electroredeposition is another technique to realize the stability of Cu + oxidation state at high negative potential, which is preferable for enhanced catalytic activity of CO 2 ER for the formation of hydrocarbons specifically ethylene . The formation of its bimetallic with other transition metals is a common technique for modification of Cu and its derivatives to prepare new forms of catalyst species such as Sn–Cu, Ni–Cu, Pd–Cu, Au–Cu, etc., which can catalyzes CO 2 better than individual atoms …”

“…Currently, various efforts are performed to develop and promote green (renewable) energy sources; although until now majority of energy consumption is obtained from nonrenewable sources specifically fossil fuels that contribute the increment of carbon dioxide level in the atmosphere in addition to other causes such as deforestation of plants and natural sources of CO 2. For this reason, controlling and minimization of its emission using different methods such as electrochemical, biochemical, photochemical, thermochemical and hydrothermal reduction of CO 2 to convert into various essential compounds and simultaneously energy generating are one of crucial tasks to solve the challenge …”

“…Electrochemical conversion method of CO 2 has notable advantages because it is not affected by geology, amount of sunlight, or weather, as such it can performed at ambient conditions . A desirable electrocatalyst for CO 2 reduction should have a low overpotential for catalysts and to derive a large turnover frequency (TOF), and at the same time the catalyst should be stable and selective .…”

Coupled Copper–Zinc Catalysts for Electrochemical Reduction of Carbon Dioxide

“…They found that the selectivity for ethanol (C 2 H 5 OH) versus C 2 H 4 production can be tuned by varying the amount of Zn in the bimetallic catalysts. Keerthiga and Chetty [27] reported that electrodeposition of Zn on a Cu substrate can inhibit HER and enhance CH 4 formation with a faradaic efficiency (FE) of 52 %. Yin et al [28] investigated Cu-Zn alloy materials prepared by a vacuum sealing method for the electrochemical and photoelectrochemical reduction of CO 2 .…”

The Sensitivity of Cu for Electrochemical Carbon Dioxide Reduction to Hydrocarbons as Revealed by High Throughput Experiments

“…7 While improved selectivity for 2 eproducts has been achieved, success in increasing FE for higher order products has been more limited, as discussed further below. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] Comparison among reported Cu-alloy systems is limited by the variation in catalyst syntheses and morphologies in these studies, motivating the systematic study of different alloying elements and alloying concentrations in the present work.…”