Simple routes for the improvement of hydrogen evolution activity of Ni-Mo catalysts: From sol-gel derived powder catalysts to graphene supported co-electrodeposits

Gutić, Sanjin J.; Jovanović, Aleksandar Z.; Dobrota, Ana S.; Metarapi, Dino; Rafailović, Lidija D.; Pašti, Igor A.; Mentus, Slavko

doi:10.1016/j.ijhydene.2017.11.131

Cited by 27 publications

(16 citation statements)

References 64 publications

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“…Several strategies are employed to increase the activity of Ni−Mo, such as nanostructuring or using nanoparticles . It can also be combined with light‐absorbing materials as a co‐catalyst .…”

Section: Introductionsupporting

confidence: 73%

“…A lot of work is focused on studying the synthesis of Ni−Mo by changing the morphology and composition . A Ni content of 60–80 % in these alloys has been found to be optimal for the activity and stability . However, although some previous works have shown that Ni−Mo is unstable in alkaline media, the origins of this instability have not been extensively studied to date, aside from one key work by Schalenbach et al., who reported that Ni−Mo can form multiple crystal phases depending on the ratio between Ni and Mo.…”

Section: Introductionmentioning

confidence: 84%

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Electrolyte Effects on the Stability of Ni−Mo Cathodes for the Hydrogen Evolution Reaction

et al. 2019

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Water electrolysis to form hydrogen as a solar fuel requires highly effective catalysts. In this work, theoretical and experimental studies are performed on the activity and stability of Ni−Mo cathodes for this reaction. Density functional theory studies show various Ni−Mo facets to be active for the hydrogen evolution reaction, Ni segregation to be thermodynamically favorable, and Mo vacancy formation to be favorable even without an applied potential. Electrolyte effects on the long‐term stability of Ni−Mo cathodes are determined. Ni−Mo is compared before and after up to 100 h of continuous operation. It is shown that Ni−Mo is unstable in alkaline media, owing to Mo leaching in the form of MoO42−, ultimately leading to a decrease in absolute overpotential. It is found that the electrolyte, the alkali cations, and the pH all influence Mo leaching. Changing the cation in the electrolyte from Li to Na to K influences the surface segregation of Mo and pushes the reaction towards Mo dissolution. Decreasing the pH decreases the OH− concentration and in this manner inhibits Mo leaching. Of the electrolytes studied, in terms of stability, the best to use is LiOH at pH 13. Thus, a mechanism for Mo leaching is presented alongside ways to influence the stability and make the Ni−Mo material more viable for renewable energy storage in chemical bonds.

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Section: Introductionsupporting

confidence: 73%

Section: Introductionmentioning

confidence: 84%

Electrolyte Effects on the Stability of Ni−Mo Cathodes for the Hydrogen Evolution Reaction

et al. 2019

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“…The sol-gel technique provides wide possibilities for the synthesis of multicomponent oxide systems with desired chemical properties. Thus, Gutić et al [ 23 ] used the sol-gel method to obtain the Ni-Mo oxide precursor of Ni-Mo alloy powders for hydrogen evolution reaction. Umapathy et al [ 24 ] prepared NiMoO 4 nanoparticles for photocatalytic degradation purposes.…”

Section: Introductionmentioning

confidence: 99%

Sol-Gel-Prepared Ni-Mo-Mg-O System for Catalytic Transformation of Chlorinated Organic Wastes into Nanostructured Carbon

et al. 2020

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The present work aimed to prepare Ni-Mo particles distributed within the MgO matrix. With this purpose in mind, a ternary Ni-Mo-Mg oxide system was synthesized by a sol−gel approach. The samples were studied by low-temperature nitrogen adsorption, X-ray diffraction analysis, and transmission electron microscopy equipped with energy dispersive X-ray analysis. Both the nickel and molybdenum species in the prepared samples were characterized by a fine and uniform distribution. The diffraction pattern of the ternary system was predominantly represented by the MgO reflections. The catalytic activity of the samples was tested in the decomposition of 1,2-dichloroethane used as a representative of the chlorinated organic wastes. The nanostructured carbon filaments resulting from the decomposition of the halogenated substrate were found to be characterized by a narrow diameter distribution, according to the transmission electron microscopy data, thus confirming the fine distribution of the active Ni-Mo particles. The results obviously show the advantages of the sol−gel technique for obtaining efficient catalysts.

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“…[24,41,42,62] Considering hydrogen evolution, which is the focus of this thesis: on one hand, a material that would be too strongly binding would form hydrides. [23,24,63,64] On the other hand, too weakly bonding materials would not adsorb hydrogen and thus not act as a catalyst. [24,41,42] This resulted in the well-known shape of the volcano plot, as shown in Figure 1.9.…”

Section: Electrocatalysts For the Hydrogen Evolution Reactionmentioning

confidence: 99%

“…One of the main reasons hailed for the activity of these materials is the synergy between a material on the ascending branch (too strongly binding) like Ni or Co, with a material on the descending branch (too weakly binding) like W or Mo. [23,53,63,65,66] This is not the case for all the materials in the graph, however, such as NiFe or NiCoFe, where all materials are on the ascending branch. [4] Such reasons add to the debate about whether the volcano plot is correct since making such plots depend greatly on experimental conditions.…”

Section: Electrocatalysts For the Hydrogen Evolution Reactionmentioning

confidence: 99%

Characterization of Ni-Mo based Electrocatalysts for Hydrogen Evolution from Water

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I look over at my dad, wondering what the old geezer is going on about this time. Dad keeps on reminiscing: "They already predicted the future more than an age ago, son." I sigh, "And what future is that then?" "Water, as a fuel. Finally, after such a long time, it's becoming the truth." "Sure, if that's so why didn't they go for it right away then? We've got water aplenty." "They had the idea already, but not the technology." "What technology then?" Dad smiles, looking at the large TV and the phone in my hand. "All kinds of technology, efficient ways to make electricity and catalysts to split this water, to name a few" "And then what's stopping them now, we've got those now I guess?" My dad sighs and looks downcast. "Money, son, that would be money." The quote 'You were born too soon, Pencroft' is from Jules Verne -The Mysterious Island (1874) Figure 1.6: Schematic view on a complete PEC cell with nanorod photo-absorbers. On the left the photo-anode is shown which performs the water oxidation with the nanoparticle co-catalyst strategy. On the right the photo-cathode performs the proton reduction with the multilayer strategy. An electrical bias can be applied between the electrodes to increase the reaction rate.

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Simple routes for the improvement of hydrogen evolution activity of Ni-Mo catalysts: From sol-gel derived powder catalysts to graphene supported co-electrodeposits

Cited by 27 publications

References 64 publications

Electrolyte Effects on the Stability of Ni−Mo Cathodes for the Hydrogen Evolution Reaction

Electrolyte Effects on the Stability of Ni−Mo Cathodes for the Hydrogen Evolution Reaction

Sol-Gel-Prepared Ni-Mo-Mg-O System for Catalytic Transformation of Chlorinated Organic Wastes into Nanostructured Carbon

Characterization of Ni-Mo based Electrocatalysts for Hydrogen Evolution from Water

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