Efficient CO2 Electroreduction on Tin Modified Cuprous Oxide Synthesized via a One-Pot Microwave-Assisted Route

Juqin Zeng,Marco Fontana,M Amin Farkhondehfal,Adriano Sacco,Candido Fabrizio Pirri,Filippo Drago,Micaela Castellino

doi:10.3390/catal11080907

Abstract

Bimetallic copper-tin catalysts are considered cost-effective and suitable for large-scale electrochemical conversion of CO2 to valuable products. In this work, a class of tin (Sn) modified cuprous oxide (Cu2O) is simply synthesized through a one-pot microwave-assisted solvothermal method and thoroughly characterized by various techniques. Sn is uniformly distributed on the Cu2O crystals showing a cube-within-cube structure, and CuSn alloy phase emerges at high Sn contents. The atomic ratio of Cu to Sn is found to be crucially important for the selectivity of the CO2 reduction reaction, and a ratio of 11.6 leads to the optimal selectivity for CO. This electrode shows a high current density of 47.2 mA cm−2 for CO formation at −1.0 V vs. the reversible hydrogen electrode and also displays good CO selectivity of 80–90% in a wide potential range. In particular, considerable CO selectivity of 72–81% is achieved at relatively low overpotentials from 240 mV to 340 mV. During the long-term tests, satisfactory stability is observed for the optimal electrode in terms of both electrode activity and CO selectivity. The relatively low price, the fast and scalable synthesis, and the encouraging performance of the proposed material implies its good potential to be implemented in large-scale CO2 electrolyzers.

Highlights

Electrochemical conversion of carbon dioxide (CO2 ) can create a bridge between the carbon capture/storage process and the renewable energy technology
Some CuSn alloys with various stoichiometry show X-ray diffraction (XRD) patterns that mainly consist of only one dominant peak in the 42–43◦ 2θ range [22,23]
Other samples with different Cu:Sn atomic ratios have been characterized by XRD

Summary

Introduction

Electrochemical conversion of carbon dioxide (CO2 ) can create a bridge between the carbon capture/storage process and the renewable energy technology. By utilizing clean electricity as energy input and captured CO2 as raw material, the CO2 reduction reaction (CO2 RR) can directly produce valuable chemical feedstocks, including C1 products such as carbon monoxide (CO), methane (CH4 ), methanol (CH3 OH), and formic acid (HCOOH), C2 products such as ethylene (C2 H4 ), ethane (C2 H6 ) and ethanol (C2 H5 OH), C2+ products such as n-propanol (CH3 CH2 CH2 OH) and so on [1] Among these products, the simple and small building-block molecules, CO and HCOOH, are considered to be techno-economic convenient and comparable with the conventional chemical synthesis [2].

Methods

Results

Conclusion