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Single-atom catalysts based on metal-N

Proton exchange membrane fuel cells (PEMFCs) suffer extreme CO poisoning even at PPM level (

Engineering the reaction interface to preferentially attract reactants to inner Helmholtz plane is highly desirable for kinetic advancement of most electro-catalysis processes, including hydrogen evolution reaction (HER). This, however, has rarely been achieved due to the inherent complexity for precise surface manipulation down to molecule level. Here, we build a MoS2 di-anionic surface with controlled molecular substitution of S sites by –OH. We confirm the –OH group endows the interface with reactant dragging functionality, through forming strong non-covalent hydrogen bonding to the reactants (hydronium ions or water). The well-conditioned surface, in conjunction with activated sulfur atoms (by heteroatom metal doping) as active sites, giving rise to up-to-date the lowest over potential and highest intrinsic activity among all the MoS2 based catalysts. The di-anion surface created in this study, with atomic mixing of active sites and reactant dragging functionalities, represents a effective di-functional interface for boosted kinetic performance. H2 energy as an alternative to fossil fuels requires cost-effective catalysts with fast kinetics for splitting water. Here, authors design MoS2 materials with di-anionic surfaces to improve the electrocatalytic H2 evolution activities.

The catalytic activity of 2H-MoS2 is retarded by the deficiency in active sites, inferior intrinsic activity, and slow electron transfer kinetics. However, the strategies to concurrently resolve th...

Proton exchange membrane water electrolysis (PEMWE) technology is a high efficiency and clean route to extract H2 from pure water. As the converse process to the-state-of-the-art H2 fuel cell, PEMWE possess several merits including high energy conversion, zero emission, and the production of high purity H2. In order to push the technique into market with wider application, several issues including reduce the material cost, developing anti-corrosion current collectors, and further reducing the energy loss are imperative. In this chapter, we systemically reviewed the current status of PEMWE, comprising the basic theory and performance descriptors of the electrocatalysis process, the development of the anode and cathode materials, the membranes, the membrane electrode assembly, and the other cell components such as bipolar plate and etc. With these introductions, we hope to provide a clear picture to the readers about the scientific and technology issues that facing the PEMWE and provide guidance for future endeavors.

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. While water reduction may provide a carbon-neutral means to produce hydrogen gas, there is a scarcity of efficient, earth-abundant electrocatalysts. Here, the authors add palladium into MoS2 materials to activate and stabilize the conductive basal plane to improve the electrocatalytic activity.

The catalytic activity of 2H-MoS

Engineering the reaction interface to preferentially attract reactants to inner Helmholtz plane is highly desirable for kinetic advancement of most electro-catalysis processes, including hydrogen evolution reaction (HER). This, however, has rarely been achieved due to the inherent complexity for precise surface manipulation down to molecule level. Here, we build a MoS2 di-anionic surface with controlled molecular substitution of S sites by –OH. We confirm the –OH group endows the interface with reactant dragging functionality, through forming strong non-covalent hydrogen bonding to the reactants (hydronium ions or water). The well-conditioned surface, in conjunction with activated sulfur atoms (by heteroatom metal doping) as active sites, giving rise to up-to-date the lowest over potential and highest intrinsic activity among all the MoS2 based catalysts. The di-anion surface created in this study, with atomic mixing of active sites and reactant dragging functionalities, represents a effective di-functional interface for boosted kinetic performance., H2 energy as an alternative to fossil fuels requires cost-effective catalysts with fast kinetics for splitting water. Here, authors design MoS2 materials with di-anionic surfaces to improve the electrocatalytic H2 evolution activities.

Molybdenum disulfide (MoS2) is reckoned as one of the most positive low-cost HER catalysts to replace platinum-based precious metals in acid media. Unfortunately, some issues preclude MoS2 from being truly applicable including limited active sites, poor conductivity and lack of intrinsic activity. Herein, we report a Cu, Pd co-doped MoS2 nanomaterial as an efficient and stable HER electrocatalysts, which partially resolve the above-mentioned problems and leads to high overall performance. Specifically, we improve the electric conductivity of the MoS2 by Cu dopant and realize the phase transition of MoS2 from pristine 2H phase to stable 1T phase by Pd dopant. More importantly, we increase active site density to facilitate fast electrocatalytic Faradaic process via synergistic effects of Cu and Pd doping, and tune electronic energy states of MoS2 to improve HER intrinsic activity. In acidic media, the performance of Cu-Pd-MoS2 catalyst in terms of a low overpotential (−93 mV) at 10 mA cm−2, a small Tafel slope of 77 mV dec−1, and an excellent stability is better than that of single-doped catalysts.