Toward a green hydrogen economy: progress, economic feasibility, and challenges of liquid organic hydrogen carriers

Abstract

Driven by the global transition toward a more sustainable energy system, liquid organic hydrogen carrier (LOHC) technology has garnered growing attention for hydrogen storage and transportation, owing to its high storage capacity, favorable safety profile, and compatibility with existing energy infrastructure. This review summarizes recent advances in LOHC systems, particularly those based on aromatic hydrocarbons and N-heterocyclic aromatic compounds, with a focus on innovations in catalytic systems for hydrogenation and dehydrogenation reactions. By analyzing the structure–activity relationships of various catalysts, this review emphasizes the crucial role of active site design, as well as the synergistic effects between metal components and support materials, in enhancing hydrogen uptake and release efficiency while minimizing byproduct formation. The techno-economic feasibility of LOHC technology is also examined, including aspects such as hydrogen production, long-distance transport, and large-scale supply. Some current challenges, such as thermodynamic limitations, the decreased hydrogen storage capacity of materials, and the long-term stability of catalysts, still pose challenges to the large-scale commercialization of LOHC technology. To address these issues, a multidisciplinary approach is proposed, integrating molecular design, catalyst development, process optimization, system-level integration, and business model innovation. These strategies aim to enhance cost-effectiveness, operational performance, and scalability of LOHC technology, thereby accelerating the adoption of a hydrogen-based energy economy and supporting global carbon neutrality goals.