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.