PNNL

Abstract

Hydrogen has the highest gravimetric energy density of any energy carrier and produces water as the only waste product, making it extremely attractive for transportation and stationary power applications, and is also an important industrial chemical. However, a low volumetric energy density poses a challenge, inspiring intense efforts to develop chemical-based storage using metal hydrides, liquid carriers, and sorbents. The chemistry behind the uptake and release of hydrogen in these materials can be described as a “Goldilocks challenge,” in which the optimal binding energy falls within a narrow energy range found in few materials. In addition to meeting this criterion, a successful utilization of hydrogen as an energy carrier demands greater understanding of the complex kinetics, mass transport, and microstructural phenomena associated with hydrogen uptake and release. The goal of this Perspective is to define key challenges and show that solutions will involve a nexus of several cutting-edge subdisciplines of chemistry, including catalysis, data science, nanoscience, interfacial phenomena, and dynamic or phase-change materials.