Green hydrogen plays a crucial role in decarbonization and the future of low-carbon society. Still, its transport/distribution and cost of production, mainly realized by electrolysis, are major hurdles. Liquid H₂ carriers reduce transport/distribution costs but add further expenses for their production. To address this challenge, we proposed a novel strategy for electrocatalytic production of a liquid organic hydrogen carrier with anodic valorization of the process. This review summarizes the state of the art and outlooks in this new concept. The electrocatalytic process is briefly introduced, and the main components are discussed. Subsequently, the electrocatalytic production of liquid organic hydrogen carriers and anodic oxidation from components to processes, together with the paired processes and reactors, are analyzed, highlighting challenges and prospects.

Zeolitic imidazolate frameworks (ZIFs) based electrocatalysts for CO₂ reduction offer unique possibilities for developing advanced materials for this reaction due to their ordered nanoporosity and pore environments, tunable characteristics and high affinity for CO₂. Still, they were not investigated sufficiently. In this study, we developed a Bismuth nanodots embedded Zeolitic Imidazolate Framework-8 (BND-ZIF-8) electrocatalyst via a one-pot synthesis method for the electrochemical CO₂ reduction reaction (eCO₂RR). Comprehensive spectroscopic and electrochemical characterization confirmed the successful integration of Bismuth into the ZIF-8 matrix. The electrocatalytic performance of the BND-ZIF-8 was assessed in multiple reactor typologies such as H-cell, flow cell, and membrane electrode assembly (MEA) setups. Remarkable differences in the performances in the three cell configurations are evidenced. Notably, the MEA configuration exhibited a marked enhancement in formate selectivity, achieving a Faradic efficiency (FE) of up to 91 % at a current density of −150 mA cm^‒². This work underscores the potential of Bi-ZIF-8 in advancing eCO₂RR while remarking on the crucial importance of the appropriate type of electrocatalytic experiments in assessing the material performance.

Nanocube crystals of bimetallic Ag-Cu-Melamine molecular complexes have been originally developed as effective electrocatalysts for the CO₂ selective reduction to multicarbon products, particularly ethylene and ethanol. The bimetallic complex, containing 10 wt.% Ag demonstrates the highest performance in electro-reduction of CO₂ in both H-type and flow cells. It achieves a Faradaic efficiency of 70 % for C2 products, with 40 % attributed to ethanol and the remaining to ethylene. These results are obtained at a cathode potential of -1.0 V vs reversible hydrogen electrode (RHE) with a total current density of -50 mA·cm^-2 in the flow cell, five times higher current densities than the current densities in the H-Cell. Without Ag in the complex, only C1 products (CO and formic acid) are detected. The use of the flow cell, in addition to higher current densities, enhances C2 formation, especially ethylene, which is absent in H-type cell experiments. These novel electrocatalysts also exhibit stable performances and provide mechanistic indications of the roles of Ag and tandem cooperation with Cu.