Researchers Enhance Hydrogen Production with Single-Element Dual-Site Substitution

A new kind of molybdenum disulfide (MoS₂) catalyst is drawing attention for hydrogen production, using a “dual-site” concept to overcome a long-standing bottleneck in the hydrogen evolution reaction (HER). Researchers report that substituting a single element into two different lattice positions can dramatically improve how MoS₂ generates hydrogen in acidic environments.

The motivation is urgent: proton exchange membrane (PEM) water electrolysis can turn renewable electricity into green hydrogen, but it is often limited by the high cost of precious platinum-group catalysts. MoS₂ is a widely studied alternative, prized for its earth-abundant constituents and catalytic potential.

Yet conventional MoS₂ typically underperforms because most activity concentrates at sulfur edge sites, while the basal plane remains relatively inert. For practical electrolyzers that must run at high current densities, simply increasing material quantity is not enough—the catalyst must expose and stabilize active regions across both edges and planes.

In a paper featured in Angewandte Chemie International Edition, scientists from the Dalian Institute of Chemical Physics (CAS) led by Profs. DENG Dehui, CUI Xiaoju, and YU Liang describe a dual-site substitution strategy. Te atoms are engineered to simultaneously replace both Mo and S atoms within the MoS₂ lattice, creating a Te–MoS₂ structure with enhanced catalytic behavior.

Electrochemical testing shows striking performance. The Te–MoS₂ catalyst needs only 364 mV overpotential to reach an industrial-level current density of 1000 mA·cm⁻² in acidic electrolyte—far below the 662 mV reported for commercial 20 wt% Pt/C. Even more important for scale-up, the catalyst sustains stable operation for 200 hours without noticeable decay.

Analysis suggests the substitution does more than introduce defects. By reshaping local bonding and electronic structure, Te atoms activate neighboring sulfur atoms and encourage the formation of smaller, edge-rich MoS₂ nanosheets. This yields abundant active sites not only at edges but also across the basal plane, while tuning hydrogen adsorption to be more favorable.

The researchers frame their work as “single-element dual-site substitution,” offering a design principle that may help other earth-abundant catalysts move closer to platinum-like performance. If transferable, the approach could accelerate the development of cost-effective HER electrocatalysts for real-world hydrogen production.

Keywords

Catalysis, Hydrogen evolution reaction, MoS₂, Dual-site substitution, Tellurium doping, PEM water electrolysis