Substitution of Zinc(II) in Nickel(II) Oxide as Proficient Copper-Free Catalysts for Selective CO₂ Electroreduction

In the present study, we have synthesized nanocrystalline Zn-substituted-NiO (Ni 1– x Zn x O, where x = 0.05 and 0.1) catalysts by solution combustion method and utilized for CO 2 electroreduction. X-ray diffraction (XRD) and field-emission scanning electron microscopy coupled with energy-dispersive spectroscopy (FESEM-EDS) characterizations showed pure crystalline phase of NiO with bulk doping of Zn 2+ over NiO lattices. Their ionic interaction and synergetic effect influences the redox electrochemistry of NiO. Zn substitution increases the hydrocarbon selectivity with FE% up to 47% for C 2 H 4 and CH 4 at −1.4 V. While ZnO alone is known to produce CO and NiO is inactive for CO 2 electroreduction. However, their solid solution reduces CO 2 with high efficiency and enhanced hydrocarbon selectivity due to Ni 2+ and Zn 2+ ionic interaction.