## 1 Introduction  
To achieve the global climate targets, the investigation of new technologies for a decarbonized energy production and storage method as well as defossilised chemical production method is inevitable. With the use of renewable electricity generated from solar or wind sources, CO2 can be used as raw material for the electrochemical CO2 reduction reaction (eCO2 RR) [1; 2; 3; 4; 5]. The electrochemical conversion of CO2 into a diverse spectrum of chemicals is a potential technology to change the role of CO2 from harmful waste to a valuable resource. Depending on the electrocatalyst, value-added products such as CO, formate/formic acid, alcohols, and other hydrocarbons can be produced from CO2 by the eCO2 RR reaction [6; 7; 8; 9; 10]. Besides CO, formate/formic acid is an easily accessible product that can be used in various industrial applications and in downstream processes in the chemical industry [4; 11; 12]. The most common catalysts for the eCO2 RR reaction to formate/formic acid are based on tin (Sn) and bismuth (Bi). Both of these elements exhibit high selectivity towards formate/formic acid and high overpotentials towards the hydrogen evolution reaction [4; 13; 14; 15; 16; 17; 18; 19]. Additionally, these catalysts are of interest because of their non-toxic properties and low cost [20]. To achieve industrially relevant current densities of 200 mA\(\cdot\)cm\({}^{-2}\) and greater, the use of gas diffusion electrodes (GDEs) is necessary [21; 22]. State-of-the-art GDEs are fabricated by depositing a catalyst layer on a gas diffusion layer (GDL) [23; 24]. This is typically performed by spray coating an ink [25; 26; 27; 28] consisting of the catalyst, a binder, and a solvent onto the gas diffusion layer. Typically, to obtain the catalyst, the active phase (electrocalyst) is deposited on a conducting support consisting of mainly carbon materials by a precipitation process [29]. Electrodeposition is a cost-effective and uncomplicated method that offers the possibility to selectively place catalyst particles at active positions of the triple-phase boundary [30]. Through a suitable choice of substrate, process, and electrolyte parameters, the nucleation rate and morphology of the precipitates can be influenced. As shown in the literature, defects, grain sizes, and orientation of the catalyst material that can be influenced in this way have a decisive influence on the selectivity and activity of the catalyst in the electrochemical CO\({}_{2}\) reduction [14; 15; 16; 17; 18; 31; 32; 33; 34; 35; 36; 37]. Compared with the other techniques available, electrodeposition is the most straightforward method to fabricate large electrodes for real industrial electrolysers. Aside from galvanostatic deposition, pulse current deposition (pulse plating, PP) is one of the most commonly techniques used in electrodeposition. It is known that the morphology, microstructure, hardness, ductility, porosity, and surface roughness of electrodeposits are impacted by the process parameters [20]. PP also yields a finer, homogeneous surface appearance because it is possible to achieve higher instantaneous current densities during electrodeposition. In the literature, various metals (Sn, Bi, Pb, Hg, In) [13; 21; 22; 23; 24; 25; 26; 27; 29; 30; 31; 32; 33; 38; 39; 40; 41] have been investigated for the production of formate from CO\({}_{2}\) by electrolysis according to the following reaction:  
\[\mathrm{CO_{2}+H_{2}O+2e^{-}\rightleftharpoons HCOO^{-}+OH^{-}\,E_{0}=-0.72\,V} \tag{1}\]  
In most of the published papers, the catalyst precursors were deposited using the precipitation method, or the catalyst was used in the form of an ink. Some authors used electrodeposited catalysts on planar electrode substrates [15; 42; 43; 44; 45; 46; 47; 48; 49]. Only a few papers used GDEs/GDLs as the substrate for electrochemical deposition of Bi or Sn [50; 51; 52]. Usually, the electrodes have been investigated at low current densities [15; 42; 43; 44; 45; 46; 47; 48] and short reaction times [15; 43; 45; 47; 49; 52; 53; 54].