Performance of xMg3Al1-LDH@ZIF-8 in High Efficiency Electrocatalytic Reduction of CO2 to CO

Abstract

This study involves the preparation of the precursor of magnesium aluminum layered double hydroxide (Mg₃Al₁-LDH) through a hydrothermal synthesis method. Subsequently, altering the loading amount of the precursor to synthesize a series of nanomaterials (xMg₃Al₁-LDH@ZIF-8, x = 0.2, 0.5, and 0.8) composite with zeolitic imidazolate framework-8 (ZIF-8). The investigation delves into the electrocatalytic performance of the material in the electrochemical reduction of CO₂ (CO₂RR) for the production of CO. The electrocatalyst is subjected to analysis through various techniques such as XRD, XPS, Raman, FTIR, SEM, EDS, TEM, BET, etc., to examine the elemental composition, microscopic morphology, and surface area with pore size. The electrochemical performance of the materials is tested and analyzed using an electrochemical workstation and gas chromatograph. The research findings reveal that the electrocatalyst with a loading amount of 0.5 g, denoted as 0.5Mg₃Al₁-LDH@ZIF-8, exhibits a well-defined rhombic dodecahedral morphology with a surface-attached layered structure. This structure, characterized by relatively strong interactions, provides abundant active sites for the reaction, consequently demonstrating superior electrochemical performance. The Faradaic efficiency (CO FE) for CO₂RR to produce CO reaches a maximum of 88.08% at −1.5 V vs. RHE. Maintaining a constant applied voltage at −1.4 V vs. RHE ensures stability for up to 4 h.