Cu-doped molybdenum carbide encapsulated within two-dimensional nanosheets assembled hierarchical tubular nitrogen-doped carbon for enhanced hydrogen evolution

Advances in electrocatalytic dehydrogenation of ethylamine to acetonitrile

The electrocatalytic dehydrogenation of ethylamine (EDH), owing to its high hydrogen content, holds broad prospects in electrochemical hydrogen (H2) production, H2 storage, and addressing energy issues, thus deserving wide attention. In this feature article, we first summarized the fundamentals of thermocatalytic and electrocatalytic EDH and reviewed the recent state-of-the-art advances in catalyst research, specifically platinum group metal (PGM) catalysts and non-PGM catalysts. We systematically discussed the potential applications of electrocatalytic EDH in energy storage and conversion. Finally, we provide our perspective on the key challenges and future developments in this field. We believe this feature article will offer helpful guidance for oriented design and optimization of stable and efficient catalysts for electrocatalytic EDH and related energy applications.

Simple synthesis of peanut shell-like MoCoFe-HO@CoMo-LDH for efficient alkaline oxygen evolution reaction

Due to the depletion of fossil energy on earth, it is crucial to develop resource rich and efficient non-precious metal electrocatalysts for oxygen evolution reaction (OER). Herein, we synthesized an efficient and economical electrocatalyst using a simple self-assembly strategy. Firstly, rod-shaped MIL-88A was synthesized by hydrothermal method. Then, the surface of MIL-88A was functionalized and encapsulated in zeolitic imidazolate framework-67 (ZIF-67) by hydrothermal method. The combination of MIL-88A and ZIF-67 resulted in a slight ion-exchange reaction between Co2+ and the surface of MIL-88A to generate CoFe-LDH@ZIF-67 core-shell structure. Afterwards, in the presence of Mo6+, ZIF-67 was converted into CoMo-nanocages through ion-exchange reactions, forming a core-shell structure of MoCoFe hydr (oxy) oxide@CoMo-LDH (MoCoFe-HO@CoMo-LDH). Due to the advantages of core-shell structure and composition, this material exhibits excellent OER characteristics, with a small Tafel slope (45.11 mV dec-1) and low overpotential (324 mV) at 10 mA cm-2. It exhibits good stability in alkaline media. This research work provides a novel approach for the development of efficient and economical non-precious metal electrocatalysts.

Urchin-Like Structured MoO2 /Mo3 P/Mo2 C Triple-Interface Heterojunction Encapsulated within Nitrogen-Doped Carbon for Enhanced Hydrogen Evolution Reaction

The development of highly efficient and cost-effective hydrogen evolution reaction (HER) catalysts is highly desirable to efficiently promote the HER process, especially under alkaline condition. Herein, a polyoxometalates-organic-complex-induced carbonization method is developed to construct MoO₂ /Mo₃ P/Mo₂ C triple-interface heterojunction encapsulated into nitrogen-doped carbon with urchin-like structure using ammonium phosphomolybdate and dopamine. Furthermore, the mass ratio of dopamine and ammonium phosphomolybdate is found critical for the successful formation of such triple-interface heterojunction. Theoretical calculation results demonstrate that such triple-interface heterojunctions possess thermodynamically favorable water dissociation Gibbs free energy (ΔG_H2O ) of -1.28 eV and hydrogen adsorption Gibbs free energy (ΔG_H* ) of -0.41 eV due to the synergistic effect of Mo₂ C and Mo₃ P as water dissociation site and H* adsorption/desorption sites during the HER process in comparison to the corresponding single components. Notably, the optimal heterostructures exhibit the highest HER activity with the low overpotential of 69 mV at the current density of 10 mA cm^-2 and a small Tafel slope of 60.4 mV dec^-1 as well as good long-term stability for 125 h. Such remarkable results have been theoretically and experimentally proven to be due to the synergistic effect between the unique heterostructures and the encapsulated nitrogen-doped carbon.