Effect of catalyst layer on electrochemical reduction of carbon dioxide using different morphologies of copper

Electrochemical reduction of carbon dioxide (ERC) is one of the promising technologies for the renewable energy storage challenge and mitigation of the CO2 levels. Till now Cu has been found the best electrocatalyst for ERC but still the potential of Cu is not fully explored. This paper illustrates the effect of electrocatalyst layer formed by four different morphologies of cupper (nanorods, octahedral, spherical, and dendrite) with similar crystallite phases. Pre and post-ERC analysis of the catalyst in different environment shows that same crystal facet is formed at the end of ERC, indicating that the crystal rearrangement occurred during ERC is independent of the environment and does not promote any particular reaction. Nanorods form intercalated layers with an extended surface giving maximum faradaic efficiency of 26% at a lower cell voltage of −2.75 V. Dendrites forms porous layers, which are filled by the gas formed during ERC and thus decreases the active surface. However, the entrapped intermediates provide sufficient residence time and conditions for C2H4 and C2H6 formation. Spherical nanoparticles and octahedral nanoparticles formed a smooth, and thin layer with minimum faradaic efficiency towards ERC.