The lack of Pt-based and low-Pt-type cost-effective hydrogen evolution catalysts is a major factor in the commercial application of hydrogen electrolysis for decades. The current difficulties are: lack of simultaneous solution of catalyst intrinsic activity, active site density, conductivity and Strategy for stability problems. Low/non-Pt catalysts can achieve true application in HER catalysis only when electronic conductivity, active site density, intrinsic activity and stability issues are simultaneously addressed.
Recently, Xing Wei, a researcher at the Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, combined with Shanghai Light Source and Southeast University to jointly tackle the MoS2 hydrogen evolution system, initiated a spontaneous interface redox doping method to activate molybdenum disulfide (MoS2) with a low amount of palladium atoms. The inert surface has a low-cost, high-efficiency stable HER catalytic material. Pd doping replaces the Mo site, simultaneously introduces sulfur vacancies and induces a MoS2 phase transition to form a stable 1T structure. Theoretical calculations show that it is located next to the palladium site. The sulfur atom exhibits low hydrogen adsorption energy (ΔGH=-0.02eV). The final MoS2 doped with only 1wt% palladium exhibits an ultra-low hydrogen evolution overpotential (the overpotential corresponding to 10mA·cm-2 is only 78mV) and high. The current density (805μA·cm-2) is exchanged, and it has good stability, which makes it possible to replace commercial Pt/C. At present, the catalyst has the highest HER performance in the hetero atom-doped MoS2 based materials reported in the literature. The development was published in Nature-Communication on the topic of Chemically activating MoS2 via spontaneous atomic palladium interfacial doping towards efficient hydrogen evolution (Nature Communications, 2018, 1, 9 , 2120) .
In terms of low Pt catalysts, the research group recently studied surface Pt-enriched PtRu nanoparticles, in which PtRu partially embedded in the surface of carbon spheres to form a highly efficient hydrogen evolution catalyst. Using polymerization, by optimizing the addition time of the precursor (6h optimal) PtRu alloy (PtRu@RFCS-6h) partially embedded in phenolic resin carbon spheres, Pt is preferentially precipitated on the surface of PtRu alloy under high temperature reducing atmosphere to form Pt nanoclusters with smaller particle size. A large number of Pt catalytic sites are provided under the premise of stability. Experiments show that the PtRu@RFCS-6h catalyst HER overpotential in the 0.5MH2SO4 system (19.7mV and 43.1mV respectively at 10 and 100mA·cm-2 current density), TOF (4.03H2s-1), Tafel slope (27.2mVdec-1) and stability are better than commercial Pt/C catalysts. The results show that the trace Pt nanoclusters enriched on the surface of PtRu alloy can be effectively reduced. The adsorption energy of H is beneficial to the dissociation of hydrated protons. In addition, the preparation process of the catalyst is simple, the loading of precious metal Pt is 99.9% less than that of commercial Pt/C catalyst, and the cost is only 2% of commercial Pt/C catalyst, which is an alternative commercial Pt. /C offers the possibility The results are published in Energy & Environmental Science entitled Enhanced electrocatalytic performance for hydrogen evolution reaction through surface enrichment of platinum nanocluster alloying with ruthenium in-situ embedded in carbon (Energy & Environmental Science, 2018, 5, 11, 1232-1239).
Mechanism of Pd spontaneously doping MoS2
Structure and properties of synthesized ultra-low loading Pt catalyst
