The development of gas diffusion electrodes (GDEs) has enabled electrochemical carbon dioxide reduction to achieve industrially-relevant current densities while avoiding both parasitic hydrogen evolution, which is often observed when using proton-conducting polymer electrolytes, and parasitic sorption of the carbon dioxide, which is often observed when using hydroxide-conducting polymer electrolytes. A GDE mimics the triple phase boundary of membrane electrode assemblies (MEAs) used for electrochemical hydrogen technologies, with the polymer electrolyte replaced by a liquid, often aqueous, electrolyte. While strategies for managing the gas-liquid-solid boundary of the reactant stream, electrolyte, and catalyst are less mature than those of MEAs, considerable progress has been made in GDE systems by employing a hydrophobic gas diffusion layer (GDL), such as polytetrafluoroethylene (PTFE), with a metal catalyst coating on the electrolyte-facing side. The manual assembly and operation of GDEs into electrochemical cells present an opportunity to accelerate experimentation via automation. Materials acceleration platforms (MAPs) comprise strategies for integrating experiment automation and data science, which hold great promise for developing electrocatalysts in general and CO2 reduction systems in particular. In the ecosystem of MAPs for electrocatalyst discovery, a host of techniques have been developed for bulk liquid electrolytes, including for CO2 reduction with analytical quantification of product distribution. Driven mostly by fuel cell technologies, high throughput screening has also been demonstrated for MEAs. Building upon these concepts, high throughput screening of GDEs for the electroreduction of dinitrogen was demonstrated with a 16-channel parallel testing system. In the present work, we demonstrate an instrument that automates GDE cell assembly and screening in a manner suitable for future incorporation in a MAP via integration with robotic synthesis and GDE sample exchange. We are not aware of comparable hardware for automating the operation of a GDE electrochemical cell for incorporation into a MAP. The description of the instrument and its validation using a PTFE-supported Cu GDE are provided below. The Supporting Information and associated data repository include pseudo-code for operation, Python code for incorporation into the HELAO-async instrument control platform, a fabrication guide, machining instructions for custom parts, computer drawings, and a bill of materials with estimated pricing.