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 (Ni1–xZnxO, where x = 0.05 and 0.1) catalysts by solution combustion method and utilized for CO2 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 Zn2+ 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 C2H4 and CH4 at −1.4 V. While ZnO alone is known to produce CO and NiO is inactive for CO2 electroreduction. However, their solid solution reduces CO2 with high efficiency and enhanced hydrocarbon selectivity due to Ni2+ and Zn2+ ionic interaction.