Synthesis of Surfactant-Modified Copper Molybdate Nanorod and Its Catalytic Activity Study toward the Electrochemical Conversion of CO2 to Acetaldehyde and C–C Coupling

In this study, hexadecyl trimethylammonium bromide (CTAB) surfactant-modified copper molybdate (CuMoO4) nanorod material was synthesized for the electrocatalysis of CO2 in a H cell reactor where CMO3 (CuMoO4 with the 0.5 g loading of CTAB surfactant) helped the formation of acetaldehyde with Faradaic efficiency of 41%. The long positive alkyl chain of CTAB directs the growth of copper molybdate nanomaterial in a three-dimensional nanorod shape, and this rodlike structure of copper molybdate provides exposed surface area for the successful electrochemical reduction of CO2. The production of C3 products like n-propanol and iso-propanol was successful due to the tremendous conductive character of the Cu element in CuMoO4. Copper molybdate (CMO3), the smallest particle size among all the compositions, performed extremely well under suitable potential range and facilitates high selectivity (80%) of the formation of acetaldehyde at a potential of −0.931 V vs RHE upon lowering of the hydrogen evolution reaction. The free energies of the molecule were determined theoretically using the density of states (DOS) of CuMoO4, and density functional study of the CO2 reduction pathway to acetaldehyde was accomplished by considering the free energy of intermediate charge transfer species.