Durability For Hydrogen Evolution Reaction Research Articles

Quasi-Amorphous Metallic Nickel Nanopowder as an Efficient and Durable Electrocatalyst for Alkaline Hydrogen Evolution.

Nickel is regarded as the best alternative metal electrocatalyst to platinum for hydrogen evolution reaction (HER). Success in developing a quasi‐amorphous metallic nickel (QAMN) nanopowder catalyst using a two‐step chemical route for efficient and durable HER in alkaline solution is reported. It is found that the QAMN electrocatalyst exhibits essentially zero overpotential at the cathodic onset while delivering 10 mA cm−2 at an overpotential of only 240 mV; both performances are far better than what was reported previously using prior metallic nickel catalysts. Taking into account increased surface area, further enhanced activity is attributed to the superior intrinsic activity. Meanwhile, the QAMN catalyst shows excellent stability in accelerated and interrupted polarization in alkaline solution for tens of hours. This study provides a new chemical means to prepare amorphous metallic materials for more efficient catalysis.

Recent progress on earth abundant electrocatalysts for hydrogen evolution reaction (HER) in alkaline medium to achieve efficient water splitting – A review

Developing earth-abundant-electrocatalysts for hydrogen evolution reaction is one of the promising ways to achieve efficient water-splitting for hydrogen production (a clean chemical fuel). This paper reviews the activity, stability and durability for hydrogen evolution reaction in alkaline medium of different types of recently reported potential electrocatalysts such as Ni, Co, NiCo, Fe, Cu, W, Mo, Se, Mn, Zn, V, and metal free based earth-abundant-electrocatalysts. Further, this paper reviews the strategies used to achieve the remarkably low overpotential (including η10: ≤ 35 mV), high long term stability (including ≥ 100 h) and high durability (including ≥ 5000 cycles) of potential earth-abundant-electrocatalysts for hydrogen evolution reaction in alkaline medium and those are better or well comparable with the state-of-the-art, noble, Pt/C electrocatalyst. Finally, this paper summarizes the efficient strategies such as preparing porous structured materials, preparing nanostructured materials with superaerophobic surface, preparing nanostructured materials, preparing carbon composites/integrating electrocatalysts with carbon, preparing amorphous materials, preparing materials with oxygen vacancies/defects, preparing metal chalcogenides, preparing bimetallic/multi-metallic materials, doping metals or heteroatoms, preparing electrocatalysts with core-shell structure, decorating electrocatalysts with amines, preparing homo-junction/heterojunction structured materials, preparing hollow structured materials, and preparing boron-rich surface to enhance the activity, stability, and durability for HER.

Solvothermal Synthesis of Monodisperse PtCu Dodecahedral Nanoframes with Enhanced Catalytic Activity and Durability for Hydrogen Evolution Reaction

Nanoframes (NFs) with highly open structures have attracted substantial attention because of their large surface area, three-dimensional structure and good stability, which are of significance to enhance the catalytic characters. However, it is still challenging to develop facile and efficient method to construct Pt-based NFs with tailored structures. Herein, a simple solvothermal method was developed to prepare monodisperse PtCu dodecahedral nanoframes (PtCu DNFs), where cetyltrimethylammonium chloride (CTAC) served as the structure-director and dispersing agent, oleylamine as reductant, allantoin as the co-structure-director and coreductant. The PtCu DNFs displayed remarkably improved catalytic performances for hydrogen evolution reaction (HER) in both acid and alkaline electrolytes relative to homemade PtCu nanopolyhedrons (NPHs), commercial Pt/C (20 wt%) and Pt black catalysts. The work offers some instructive guidelines for synthesis of novel metallic NFs as efficient HER catalysts.

Hollow Ag44Pt56 nanotube bundles with high electrocatalytic performances for hydrogen evolution and ethylene glycol oxidation reactions

It is a main challenge to synthesize highly efficient and durable nanocatalysts towards hydrogen evolution reaction (HER) and alcohol oxidation reaction in energy conversion and storage. Herein, a green wet-chemical approach was developed to directly prepare hollow Ag44Pt56 nanotube bundles (H-Ag44Pt56 NTBs), utilizing 5-azacytosine as a structure-directing agent. The obtained electrocatalyst displayed superior catalytic activity and durability for HER in acid media, and the great improvement in catalytic performance for ethylene glycol oxidation reaction (EGOR) in the alkaline electrolyte, outperforming home-made Ag34Pt66 nanoparticles (NPs), Ag70Pt30 NPs, and commercial Pt/C catalysts. The high electrocatalytic characters are mainly attributed to the special nanostructures and the synergetic effects between the bimetals.

Three-Dimensional Hierarchical Nickel Cobalt Phosphide Nanoflowers as an Efficient Electrocatalyst for the Hydrogen Evolution Reaction under Both Acidic and Alkaline Conditions

The sustainable hydrogen fuel from water electrolysis demands the development of efficient and robust non-noble electrocatalysts for the hydrogen evolution reaction (HER). Tuning the morphology and chemical composition is paramount to constructing electrocatalysts with superior activity and stability. In this work, novel ternary nickel-doped cobalt phosphide (Ni–Co–P) nanoflowers assembled by porous and unltrathin nanosheets were first prepared by a facile solvothermal reaction following a phosphidation procedure. The Ni–Co–P nanoflowers exhibited remarkable electrocatalytic HER performance, exhibiting overpotentials of as low as 83 and 92 mV at 10 mA cm–2 and small Tafel slopes of 46.6 and 49.6 mV dec–1 under1 M KOH and 0.5 M H2SO4 conditions, respectively, which was one of the most active earth-abundant electrocatalysts. Additionally, the electrocatalysts exhibited high durability for HER under both alkaline and acidic conditions. Various techniques further demonstrated that the superior activity of Ni–...

Ru2P Nanoparticle Decorated P/N-Doped Carbon Nanofibers on Carbon Cloth as a Robust Hierarchical Electrocatalyst with Platinum-Comparable Activity toward Hydrogen Evolution

It is desirable yet challenging to develop highly active and durable hydrogen evolution reaction (HER) electrocatalysts with Pt-comparable activity for future energy devices. In this work, we report Ru2P nanoparticle decorated P/N dual-doped carbon nanofibers on carbon cloth (Ru2P@PNC/CC-900) as a highly efficient and durable hierarchical HER electrocatalyst in both acidic and alkaline media. Electrochemical tests show that this Ru2P@PNC/CC-900 possesses Pt-comparable HER activity to support 10 mA cm–2 HER current density at low overpotential of 15 and 50 mV in acidic and alkaline condition, respectively. Density functional theory calculations reveal that coupling Ru2P nanoparticles with heteroatom-doped carbon fibers leads to enhanced intrinsic HER activity. The integrative hierarchical architecture further endows high surface areas with good mechanical robustness to support abundant catalytically active sites and possesses excellent electrical conductivity and efficient access for mass transportation to...

Molybdenum carbide/phosphide hybrid nanoparticles embedded P, N co-doped carbon nanofibers for highly efficient hydrogen production in acidic, alkaline solution and seawater

Molybdenum (Mo) based materials including its phosphides, carbides, nitrides, oxides, dichalcogenides and metallic alloys have received particular interest in recent years for sustainable hydrogen evolution reaction (HER) electrocatalysis. In this study, a novel Mo2C/MoP hybrid nanoparticle embedded N, P co-doped carbon nanofibers on carbon fiber paper (Mo2C-MoP NPC/CFP-800) is successfully prepared as a highly efficient hierarchical HER electrocatalyst. Benefitting from its structural advantages and compositional merits, this Mo2C-MoP NPC/CFP-800 electrocatalyst displays remarkable catalytic activity as well as excellent durability for HER. Only 85 and 146 mV overpotential is required to drive a HER current density of 10 mA cm−2 in acidic and alkaline solution, respectively. Remarkably, this electrocatalyst is also able to fulfill efficient HER even in seawater. Further, this work reveals that the Mo2C/MoP hybrid nanoparticle is superior to MoP nanoparticle under present system in HER electrocatalysis, which may offer valuable clues on further design and synthesis of HER electrocatalysts.

Mo2C and Its Composites Derived from Egg White for Hydrogen Evolution Reaction at All pH Range

AbstractSearching for biomass‐derived electrocatalyst with high activity and durability for hydrogen evolution reaction (HER) at all pH range is extremely desirable but remains a significant challenge. Mo2C and its nanocomposites have been controlly synthesized by pyrolyzing the mixture of molybdenum salt and egg white (EW) that served as low‐cost but environmental‐friendly carbon source. When utilized as hydrogen evolution cathode, Mo2C and its nanocomposites exhibit excellent electrocatalytic activity and stability in acidic, neutral and alkaline mediums.

Stable and Active Polymer Electrolyte Membrane Electrolyzers Utilizing Transition Metal Phosphide Hydrogen Evolution Catalysts

Electrochemical water splitting utilizing renewable electricity is a promising technology for the production of clean and sustainable hydrogen. The most active electrocatalyst for the hydrogen evolution reaction (HER) is platinum. However, the high costs and scarcity associated with platinum motivate the search for alternative catalysts.1 Promising HER activities have been reported for many families of materials including transition metal chalcogenides, carbides and in particular, phosphides.2 Specifically, cobalt phosphide (CoP) is an interesting and active non-precious metal HER catalyst in acid media.3 In this work we synthesise active and stable CoP catalysts on carbon supports at the 1 – 5 g batch scale. The CoP catalysts are prepared by wetness impregnation Vulcan carbon followed by a red phosphorous based vapour phase phosphidation. The crystal structure and chemical composition of the CoP catalyst is verified by XPS and XRD. The morphology of the catalyst is shown to consist of <20 nm particles on the surface of Vulcan carbon support by SEM. The synthesised CoP catalysts are first screened by laboratory scale three-electrode electrochemistry and demonstrate good activity for HER requiring an overpotential of 154 mV to reach -10 mA.cm-2. Beyond three-electrode laboratory scale electrochemistry screening, the most active and durable HER catalysts were used to fabricate 25 cm2 single cell stack membrane electrode assemblies (MEA). The performance of the CoP MEAs was assessed by polarization curve as well as steady state measurements at various current densities and were found to be stable for >20 h of testing. This work highlights the remarkable stability and promise of transition metal phosphides in an MEA configuration. References (1) Ng, J. W. D.; Hellstern, T. R.; Kibsgaard, J.; Hinckley, A. C.; Benck, J. D.; Jaramillo, T. F. ChemSusChem 2015, 8 (20), 3512. (2) Seh, Z. W.; Kibsgaard, J.; Dickens, C. F.; Chorkendorff, I.; Nørskov, J. K.; Jaramillo, T. F. Science 2017, 355 (6321), eaad4998. (3) Hellstern, T. R.; Benck, J. D.; Kibsgaard, J.; Hahn, C.; Jaramillo, T. F. Adv. Energy Mater. 2016, 6 (4), 1501758.

Ultrathin nitrogen-doped graphitized carbon shell encapsulating CoRu bimetallic nanoparticles for enhanced electrocatalytic hydrogen evolution

Design of highly active and cost-effective electrocatalysts is very important for the generation of hydrogen by electrochemical water-splitting. Herein, we report the fabrication of ultrathin nitrogen-doped graphitized carbon shell encapsulating CoRu bimetallic nanoparticles (CoRu@NCs) and demonstrate their promising feasibility for efficiently catalyzing the hydrogen evolution reaction (HER) over a wide pH range. The resultant CoRu@NC nanohybrids possess an alloy–carbon core–shell structure with encapsulated low-ruthenium-content CoRu bimetallic alloy nanoparticles (10–30 nm) as the core and ultrathin nitrogen-doped graphitized carbon layers (2–6 layers) as the shell. Remarkably, the optimized catalyst (CoRu@NC-2 sample) with a Ru content as low as 2.04 wt% shows superior catalytic activity and excellent durability for HER in acidic, neutral, and alkaline conditions. This work offers a new method for the design and synthesis of non-platium-based electrocatalysts for HER in all-pH.

Construction of Polarized Carbon-Nickel Catalytic Surfaces for Potent, Durable, and Economic Hydrogen Evolution Reactions.

Electrocatalytic hydrogen evolution reaction (HER) in alkaline solution is hindered by its sluggish kinetics toward water dissociation. Nickel-based catalysts, as low-cost and effective candidates, show great potentials to replace platinum (Pt)-based materials in the alkaline media. The main challenge regarding this type of catalysts is their relatively poor durability. In this work, we conceive and construct a charge-polarized carbon layer derived from carbon quantum dots (CQDs) on Ni3N nanostructure (Ni3N@CQDs) surfaces, which simultaneously exhibit durable and enhanced catalytic activity. The Ni3N@CQDs shows an overpotential of 69 mV at a current density of 10 mA cm-2 in a 1 M KOH aqueous solution, lower than that of Pt electrode (116 mV) at the same conditions. Density functional theory (DFT) simulations reveal that Ni3N and interfacial oxygen polarize charge distributions between originally equal C-C bonds in CQDs. The partially negatively charged C sites become effective catalytic centers for the key water dissociation step via the formation of new C-H bond (Volmer step) and thus boost the HER activity. Furthermore, the coated carbon is also found to protect interior Ni3N from oxidization/hydroxylation and therefore guarantees its durability. This work provides a practical design of robust and durable HER electrocatalysts based on nonprecious metals.

Large Dendritic Monolayer MoS2 Grown by Atmospheric Pressure Chemical Vapor Deposition for Electrocatalysis

The edge sites of MoS2 are catalytically active for the hydrogen evolution reaction (HER), and growing monolayer structures that are edge-rich is desirable. Here, we show the production of large-area highly branched MoS2 dendrites on amorphous SiO2/Si substrates using an atmospheric pressure chemical vapor deposition and explore their use in electrocatalysis. By tailoring the substrate construction, the monolayer MoS2 evolves from triangular to dendritic morphology because of the change of growth conditions. The rough edges endow dendritic MoS2 with a fractal dimension down to 1.54. The highly crystalline basal plane and the edge of the dendrites are visualized at atomic resolution using an annular dark field scanning transmission electron microscope. The monolayer dendrites exhibit strong photoluminescence, which is indicative of the direct band gap emission, which is preserved after being transferred. Post-transfer sulfur annealing restores the structural defects and decreases the n-type doping in MoS2 monolayers. The annealed MoS2 dendrites show good and highly durable HER performance on the glassy carbon with a large exchange current density of 32 μA cmgeo-2, demonstrating its viability as an efficient HER catalyst.

Synthesis of nickel germanide (Ge12Ni19) nanoparticles for durable hydrogen evolution reaction in acid solutions.

Desigining advanced materials as electrochemical catalysts for the hydrogen evolution reaction (HER) has caught great attention owing to the growing demand for clean and renewable energy. Nickel (Ni)-based compounds and alloys are promising non-noble-metal electrocatalysts due to their low cost and high activity. However, in most cases, Ni-based compounds and alloys have low durability in acid electrolyte, which limits their application in the electrolytic processes. In this study, monoclinic Ge12Ni19 nanoparticles were synthesized and exhibited high electrocatalytic activity and stability for the HER in acidic solution. Ge12Ni19 nanoparticles achieve an overpotential of 190 mV at cathodic current density of 10 mA cm-2 and a Tafel slope of 88.5 mV per decade in 0.50 M H2SO4 electrolyte. Moreover, the performance is maintained after a 10 000-cycle CV sweep (-0.3 to +0.1 V vs. RHE) or under a static overpotential of -0.7 V vs. RHE for 24 hours. The reported electrocatalytic performance of the Ge12Ni19 nanoparticles sufficiently proves the excellent endurance at lower required active overpotentials in acidic solution, enabling the broad applications of the Ni-based electrocatalysts. Finally, a large-area (5 cm2) electrocatalyst for HER was demonstrated for the first time. The great efficiency of the energy conversion performance sufficiently represented the potential of Ge12Ni19 nanoparticles as electrocatalysts in commercial fuel cells.

Efficient alkaline hydrogen evolution electrocatalysis enabled by an amorphous Co-Mo-B film.

An amorphous Co-Mo-B film on a Ti mesh (Co-Mo-B/Ti) is fabricated via one-step electrodeposition exhibiting a dramatically enhanced hydrogen evolution reaction (HER) performance in alkaline media. To attain a current density of 20 mA cm-2, such Co-Mo-B/Ti demands only an overpotential of 110 mV, 190 mV lower than that of the counterpart Co-B/Ti, with strong electrochemical durability to maintain its catalytic activity for at least 32 h.

Graphdiyne-WS2 2D-Nanohybrid electrocatalysts for high-performance hydrogen evolution reaction

Layered two-dimension (2D) materials have attracted substantial interest as alternative catalysts for hydrogen evolution reaction (HER). However, there exists a significant challenge in that is the only limited density of active sites concentrated at the layer edges. Herein, for the first time, graphdiyne (GD), a new generation of 2D carbon allotrope developed from the graphene family, is found to be an effective stabilizer and also a reducing agent when it is used to form a layered 2D-nanohybrid (GD-WS2 2D-NH) with WS2 owing to its highly conjugated electronic structure and low reduction potential. Further study shows that the layered GD-WS2 2D-NH synthesized with abundant active edges. Such defect-rich structure with large surface area renders ultrahigh catalytic activity and durability for HER in acidic media. Furthermore, owing to the built-in electric field formed among dissimilar layers (GD and WS2), the enhanced charge transfer leads to high activity of the basal plane sites that were inactive for the HER. As a result, the GD-WS2 2D-NH catalyst presents a reduced HER onset potential as small as 140 mV and a superior Tafel slope as low as 54 mV per decade, making the GD-WS2 2D-NH a promising stable catalyst for the HER reaction.

An extremely active and durable Mo2C/graphene-like carbon based electrocatalyst for hydrogen evolution reaction

The efficiency of hydrogen production from electrolysis of water is severely limited by the sluggish kinetics of hydrogen evolution reaction (HER). Here we report our findings in the development of a very active and durable HER electrocatalyst derived from a one-pot synthesis of highly porous molybdenum carbide (Mo2C) nanoparticles uniformly dispersed on nitrogen-doped graphene-like carbon. The nanocomposite catalyst displays excellent HER activity and durability in an acidic electrolyte among all non-noble-metal catalysts ever reported. The remarkable performance is attributed to the unique nanostructure of the Mo2C phase, the conductive nitrogen-doped graphene-like carbon network, the high porosity of the hybrid, and the synergistic effect between the Mo2C and the carbon substrate. Further, the facile and low-cost synthetic strategy for preparation of such nanostructures may open up opportunities for exploiting other high-performance electrocatalysts for various applications.

NiMoS3 Nanorods as pH-Tolerant Electrocatalyst for Efficient Hydrogen Evolution

To meet the increasing demands for sustainable and clean hydrogen energy sources, development of pH-tolerant electrocatalysts with high-performance and low-cost toward hydrogen evolution reaction (HER) is an important but challenging task. MoS2 is postulated as a promising candidate for HER in acidic solution, however, showing poor activity in alkaline media. Herein, to widen its application in various media, we first report the synthesis of NiMoS3 nanorods using a hydrothermal method that starts from NiMoO4 nanorods. The incorporation of Ni atoms in Mo–S could arouse the synergism of ternary Ni–Mo–S and create abundant defect sites, thus substantially improving the inherent catalytic activity and catalytic sites. More importantly, Ni endows Mo–S with excellent catalytic activity in alkaline solution. As a result, NiMoS3 exhibits large cathodic current, low overpotetnial, and stable durability for HER in H2SO4 and especially in KOH. The overpotetnial at current density of 10 mA cm–2 is as low as 126 mV in KOH, making it a promising candidate for HER electrocatalyst.

Highly efficient and durable MoNiNC catalyst for hydrogen evolution reaction

We report a carbothermal ammonia reduction (CAR) strategy for one-pot preparation of highly efficient and durable hydrogen evolution reaction (HER) electrocatalyst composed of earth abundant early transition metals. In this strategy, resin is applied both as the pre-binder and carbon source, and Pluronic F127 as the structure-directing agent. Upon annealing in NH3, the Mo-containing precursor on Ni foam undergoes the CAR, and simultaneously Ni from the substrate diffuses out, resulting in the formation of a quaternary complex structure of molybdenum-nickel bimetallic carbonitride (MoNiNC). The as-prepared electrode showed outstanding HER performance with an overpotential of 150mV at 50mAcm−2 and maintained steady hydrogen bubble evolution for continuous 48h. Our strategy offers a quick and simple way to fabricate earth-abundant HER electrode with highly efficient and durable electrocatalytic performance.

Ultrafine Pt nanoparticles decorated MoS2 nanosheets with significantly improved hydrogen evolution activity

Two-dimensional (2D) MoS2 has been considered as a potential catalyst in hydrogen evolution reaction (HER), but its catalytic reactions usually only occur at the active edge sites rather than the inert surfaces. In this work, we propose a strategy to enhance the catalytic activity of MoS2 by decorating the inert surfaces of MoS2 nanosheets with ultrafine Pt nanoparticles through an atomic layer deposition (ALD) technique. The optimized Pt/MoS2 catalyst with ultralow Pt mass loading (∼2.2wt%) presents exceptional HER performances in terms of low onset overpotential (31mV), small Tafel slope (52mVdec−1) and firm HER durability, which is comparable to the commercial Pt/C catalyst.

Tungsten-molybdenum oxide nanowires/reduced graphene oxide nanocomposite with enhanced and durable performance for electrocatalytic hydrogen evolution reaction

Hydrogen has attracted huge interest globally as a durable, environmentally safe and renewable fuel. Electrocatalytic hydrogen evolution reaction (HER) is one of the most promising methods for large scale hydrogen production, but the high cost of Pt-based materials which exhibit the highest activity for HER forced researchers to find alternative electro-catalyst. In this study, we report noble metal free a 3D hybrid composite of tungsten-molybdenum oxide and reduced graphene oxide (GO) prepared by a simple one step hydrothermal method for HER. Benefitting from the synergistic effect between tungsten-molybdenum oxide nanowires and reduced graphene oxide, the obtained W-Mo-O/rGO nanocomposite showed excellent electro-catalytic activity for HER with onset potential 50 mV, a Tafel slope of 46 mV decade−1 and a large cathodic current, while the tungsten-molybdenum oxide nanowires itself is not as efficient HER catalyst. Additionally, W-Mo-O/rGO composite also demonstrated good durability up to 2000 cycles in acidic medium. The enhanced and durable hydrogen evolution reaction activity stemmed from the synergistic effect broadens noble metal free catalysts for HER and provides an insight into the design and synthesis of low-cost and environment friendly catalysts in electrochemical hydrogen production.