Electrochemical reconstruction of a 1D Cu(PyDC)(H2O) MOF into in situ formed Cu–Cu2O heterostructures on carbon cloth as an efficient electrocatalyst for CO2 conversion

Abstract

Electrochemical carbon dioxide (CO₂) conversion has enormous potential for reducing high atmospheric CO₂ levels and producing valuable products simultaneously; however the development of inexpensive catalysts remains a great challenge. In this work, we successfully synthesised a 1D Cu-based metal–organic framework [Cu(PyDC)(H₂O)], which crystallizes in an orthorhombic system with the Pccn space group, by the hydrothermal method. Among the different catalysts utilized, the heterostructures of cathodized Cu–Cu₂O@CC demonstrate increased efficiency in producing CH₃OH and C₂H₄, achieving maximum FE values of 37.4% and 40.53%, respectively. Also, the product formation rates of CH₃OH and C₂H₄ reach up to 667 and 1921 μmol h⁻¹ cm⁻². On the other side, Cu–Cu₂O/NC-700 carbon composites simultaneously produced C1–C3 products with a total FE of 23.27%. Furthermore, a comprehensive study involving detailed DFT simulations is used to calculate the energetic stability and catalytic activity towards the CO₂ reduction of Cu(111), Cu₂O(111), and Cu@Cu₂O(111) surfaces. During the early phase of electrochemical treatment, Cu(II) carboxylate nodes (Cu–O) in the Cu(PyDC)(H₂O) MOF were reduced to Cu and Cu₂O, with a possible synergistic enhancement from the PyDC ligands. Thus, the improved activity and product enhancement are closely associated with the cathodized reconstruction of Cu–Cu₂O@CC heterostructures on carbon cloth. Hence, this study provides efficient derivatives of Cu-based MOFs for notable electrocatalytic activity in CO₂ reduction and gives valuable insights towards the advancement of practical CO₂ conversion technology.