Electrochemistry is a fascinating branch of science that deals with the exchange of energy between electrical and chemical forms. It focuses on processes occurring at interfaces within and between different phases of matter. Key electrochemical phenomena include the transfer of electrons and the transport of charge carriers through electrically conductive media. It is crucial to develop critical insights as these physical phenomena associated with electrochemistry are fundamental towards understanding and harnessing it for various applications. Electrochemical CO2 reduction is a process of interest to the scientific community as it can be harnessed to address the escalating anthropogenic CO2 footprint, something which is responsible for altering climate patterns across the world due to global warming. During the process of electrochemical CO2 reduction, electrons are moved to an electrode, typically a catalyst, where they are used to reduce CO2 to valuable chemicals such as hydrocarbons. Depending upon the arrangement of the electrochemical reaction cell, CO2 may either be dissolved in the electrolyte in contact with the catalyst or fed separately in its gaseous phase. In this thesis, we investigate the reduction of CO2 across multiple size scales. We first present a comparison of among the most crucial operating parameters of electrochemical CO2 reduction i.e. the current density that can be obtained through the two methods of feeding CO2 to the catalyst. This is followed by the description of a COMSOL Multiphysics based model of a Gas Diffusion Electrode where we lay out the entire process of assembling it from scratch, and then discuss crucial results including the current densities, electrolyte & gas composition among others and discuss future work. Next up, we delve deeper into an upcoming and promising strategy to increase the selectivity and yield of multi-carbon products, i.e. nano-structuring. We lay a foundation for the computation-led design of colloidosome-like nanostructures for tandem electrocatalysis of CO2, by proposing an optimum configuration and composition of these nanostructures. We also exercise temporal control within the spatially confining nano-environments to gain deeper insights into the interplay of physical and chemical kinetic processes, and the transport of species. In our recommendations for future work, we lay out certain design principles focusing on both computational and experimental directions in order to take research further ahead in this direction.