Electrified Catalysts for Endothermic Chemical Processes: Materials Needs, Advances, and Challenges

Large-scale endothermic chemical processes, as currently practiced, employ tubular reactors that are heated externally through the combustion of fossil fuels, and are highly carbon-intensive. Joule-heated reactors in which electric currents flowing through the catalyst are used to provide thermal energy directly through internal heating are rapidly emerging as an alternative to these conventional, externally heated reactors. Joule-heated reactors could help significantly improve modularity and also reduce the capital, energy, and carbon footprint associated with these enthalpically demanding processes. Development of these novel types of reactors, however, is predicated on overcoming catalyst design challenges encountered uniquely when supplying heat through the use of electric currents passing through catalyst substrates. We review herein some key advancements in catalyst design that have been achieved in the recent past, and highlight considerations critical to the novel mode of reactor operation proposed. We provide an overview of the various types of electrically heated catalysts proposed, methods used in their synthesis, and reactor performance of Joule-heated catalysts for a variety of applications. Also discussed are key knowledge gaps that will likely need to be addressed in an effort to accelerate deployment of this emerging class of reactors that could play a pivotal role in the decarbonization of energy-intensive large-scale chemical processes.