Scalable Membraneless Direct Liquid Fuel Cells Based on a Catalyst‐Selective Strategy

Abstract

This perspective presents a membraneless direct liquid fuel cell (DLFC) concept based on a catalyst‐selective strategy. The membraneless DLFCs are operated at low temperatures by employing a non‐precious cathode catalyst with a high catalytic selectivity. The uniqueness is that the inexpensive cathode catalyst only catalyzes the oxygen reduction reaction but does not catalyze the oxidation reaction of a specific fuel. Therefore, during the operation of DLFCs, the liquid fuel can enter the cathode freely without any concern of fuel crossover. This catalyst‐selective approach tactfully avoids the use of high‐cost or technically unviable ion‐exchange polymer membranes in DLFCs. The catalyst‐selective operating principle also overcomes the scalability issue of the traditional laminar‐flow membraneless DLFCs. Through a proper management of the anode and cathode catalysts in the cell, a variety of inexpensive, renewable alcohols, and small‐molecule organics can be employed as anode fuels. This innovative approach of membraneless alkaline DLFCs offers a great opportunity for the development of inexpensive energy‐generation systems for both mobile and stationary applications. In addition to summarizing the principle and the research progress of the unique membraneless DLFC platform, the challenges and future research directions are presented.