Lacking strategies to simultaneously address the intrinsic activity, site density, electrical transport, and stability problems of chalcogels is restricting their application in catalytic hydrogen production. Herein, we resolve these challenges concurrently through chemically activating the molybdenum disulfide (MoS₂) surface basal plane by doping with a low content of atomic palladium using a spontaneous interfacial redox technique. Palladium substitution occurs at the molybdenum site, simultaneously introducing sulfur vacancy and converting the 2H into the stabilized 1T structure. Theoretical calculations demonstrate the sulfur atoms next to the palladium sites exhibit low hydrogen adsorption energy at –0.02 eV. The final MoS₂ doped with only 1wt% of palladium demonstrates exchange current density of 805 μA cm⁻² and 78 mV overpotential at 10 mA cm⁻², accompanied by a good stability. The combined advantages of our surface activating technique open the possibility of manipulating the catalytic performance of MoS₂ to rival platinum.

The poor stability of Ru-based acidic oxygen evolution (OER) electrocatalysts has greatly hampered their application in polymer electrolyte membrane electrolyzers (PEMWEs). Traditional understanding of performance degradation centered on influence of bias fails in describing the stability trend, calling for deep dive into the essential origin of inactivation. Here we uncover the decisive role of reaction route (including catalytic mechanism and intermediates binding strength) on operational stability of Ru-based catalysts. Using MRuO_x (M = Ce⁴⁺, Sn⁴⁺, Ru⁴⁺, Cr⁴⁺) solid solution as structure model, we find the reaction route, thereby stability, can be customized by controlling the Ru charge. The screened SnRuO_x thus exhibits orders of magnitude lifespan extension. A scalable PEMWE single cell using SnRuO_x anode conveys an ever-smallest degradation rate of 53 μV h⁻¹ during a 1300 h operation at 1 A cm⁻².

This review showcases the recent progress in understanding and designing M–N_x/C electrocatalysts towards the ORR, aiming to provide some guidelines for their practical applications in PEMFCs.

The hydrogen evolution reaction is a crucial step in electrochemical water splitting. The most efficient catalysts for this reaction in acidic media are Pt based, but the high cost of Pt limits its practical applications. We developed a novel matrix architecture in which a trace amount of Pt is alloyed in situ with Ru nanoparticles uniformly and partially embedded in porous carbon spheres. The synthetic procedure is simple and efficient. Surface enrichment of metallic Pt nanoclusters on PtRu alloy nanoparticles results in weak bonding with hydrogen and rapid hydrated proton dissociation. These effects significantly increase the electrocatalytic activity in the hydrogen evolution process. This robust catalyst, with a Pt loading 99.9% less than that of a commercial Pt-based catalyst, gave a high turnover frequency (4.03 H₂ s⁻¹), a small Tafel slope (27.2 mV dec⁻¹), and comparable overpotentials (19.7 mV and 43.1 mV), as well as achieved current densities of 10 and 100 mA cm⁻², i.e., better than those obtained with commercial Pt/C catalyst, in 0.5 M H₂SO₄. This structure prevents nanoparticles from dissolving, agglomerating, and detaching during long-term operation; therefore there was no obvious decrease in catalytic activity after continuous reaction.