Li Zhe,Fu Jian-Yu,Feng Yi,Dong Cun-Ku,Liu Hui,Du Xi-Wen
Finding highly active and low-cost catalysts is a crucial endeavour to harvest clean hydrogen via electrochemical water splitting. Currently, the best catalyst for the hydrogen evolution reaction is based on metallic platinum whose high price severely restricts large-scale application. Here we report a silver catalyst with superior activity and durability in an acid medium that outperforms commercial platinum on carbon, especially under high applied voltages. We adopt a physical technique—laser ablation in liquid—to generate a high density of stacking faults in silver nanoparticles. We find that the stacking faults can cause a low coordination number and high tensile strain, which jointly improve the adsorption energy and transform the non-active silver into a highly active catalyst. In light of the high activity, conductivity, durability and low price, the silver catalyst can serve as a promising alternative to commercial platinum on carbon for industrial application.
Developing high-activity non-noble metal catalysts for improving the ability of water dissociation and H* adsorption/desorption in the hydrogen evolution reaction (HER) process in alkaline and neutral electrolytes is essential but remains challenging. Herein, a Mo-doped NiCoCu alloy with tuned tensile strain and localized electrons is designed and synthesized by combining the solvothermal and annealing methods for achieving ampere-level HER performance. Theoretical calculation results prove that Mo doping induces lattice tensile strain and localized electrons (electrons from Mo to the Ni/Co/Cu atoms), promoting the adsorption of O* and H* from H 2 O molecules on the Mo and Co sites and accelerating water dissociation. Therefore, NiCoCu-Mo 0.078 /CF (CF = copper foam) shows low water dissociation energy, providing sufficient H* during the HER process. Meanwhile, its H* Gibbs free energy value is near zero, implying a rapid H* adsorption/desorption process. Electrochemical results show that NiCoCu-Mo 0.078 /CF achieves better HER intrinsic activity in both a 1.0 m KOH ( η −10 /η −1000 = 35/212 mV) and a 1.0 m phosphate buffer solution ( η −10 /η −1000 = 24/256 mV) compared to NiCoCu-Mo 0 /CF and NiCoCu-Mo 0.163 /CF, and it can continuously operate for 100 h at −1000 mA cm −2 . This work shows a sustainable way to design high-performance catalysts for water electrolysis and proposes a well-performing HER catalyst.
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