A well-tamed energy conversion strategy for the valorization of CO₂ is a necessity for maintaining a check on CO₂ levels (~ 500ppm) and borrow enough time for the scientific community to perfect zero-emission fuel prospects. Mimicking photosynthetically fixed CO2 by plants in an electrochemical cell is both scientifically intriguing and sociologically promising- given more than half of world still runs on fossil fuel derived energy and standard of life are determined by the intake of energy. Catalysing CO₂RR with economical, selective heterogeneous metal nano-structures proved a promising way to improve upon the status quo.

We synthesised copper octahedrons by two electrode electrodeposition, to selectively reduce CO₂RR into CO₂+H₂ (synthesis gas) to use it as starting material in well known Fischer-tropsch reaction. In a representative experiment, copper was dissolved from a sacrificial copper anode and collected as micro-octahedrons on the surface of a platinum foil. The structures were simply tapped off the surface, cleaned, dried and used as catalyst ink to reduce CO₂ into value-added fuels. A set of experimental parameters were varied to study the effect of them on morphology, size and activity of the obtained copper powders. A pulse method involving anodic and cathodic waves passed through the copper anode was found to have a determining capability - be it shape, topology or size of the crystallites.

In a catholyte composed of 0.2 M KHCO₃, cyclo-voltammograms (CVs) were recorded in N₂ saturated and CO₂ catholyte in a 3-electrode, 2-chambered cell. From preliminary results, it was shown that CuOcta showed activity towards CO₂RR as was evident in enhanced faradaic response in CO₂ saturated catholyte. To confirm the path of fixing and valorization, a thorough gas chromatography (GC) analysis was done on the gases that were collected in a Tedlar bag. CO was found to be major reduction product in gaseous phase overcoming the inherit HER (hydrogen evolution reaction) competition on metal surfaces. A significant amount of CH₄ was also measured. The array of obtained products signal role of morphology, the surface topography of catalytic structures on the mechanism and kinetics of CO₂RR.