Electrochemical devices, such as membrane electrode assemblies and electrochemical reactors, are described herein, as well as and methods for the conversion of reactants such as carbon dioxide to value-added products such as ethanol. In certain aspects, the membrane electrode assemblies are configured to allow for distributed pressure along the cathodic side of a membrane electrode assembly is described. The pressure vessel acts as a cathode chamber, both for the feed of reactant carbon dioxide as well as collection of products. The designs described herein improves the safety of high pressure electrochemical carbon dioxide reduction and allows for varied pressures to be used, in order to optimize reaction conditions. Configurations optimized for producing preferred products, such as ethanol, are also described.