Catalytic Hydrogen Evolution Research Articles

Hybrid nanoreactors formed by interpolyelectrolyte complex formation: a colloidal platform for light-driven catalysis

Micellar interpolyelectrolyte complexes are introduced as versatile soft matter matrices for light-driven hydrogen evolution catalysis.

The meso-substituent electronic effect of Fe porphyrins on the electrocatalytic CO2 reduction reaction.

We report Fe porphyrins bearing different meso-substituents for the electrocatalytic CO2 reduction reaction (CO2RR). By replacing two and four meso-phenyl groups of Fe tetraphenylporphyrin (FeTPP) with strong electron-withdrawing pentafluorophenyl groups, we synthesized FeF10TPP and FeF20TPP, respectively. We showed that FeTPP and FeF10TPP are active and selective for CO2-to-CO conversion in dimethylformamide with the former being more active, but FeF20TPP catalyzes hydrogen evolution rather than the CO2RR under the same conditions. Experimental and theoretical studies revealed that with more electron-withdrawing meso-substituents, the Fe center becomes electron-deficient and it becomes difficult for it to bind a CO2 molecule in its formal Fe0 state. This work is significant to illustrate the electronic effects of catalysts on binding and activating CO2 molecules and provide fundamental knowledge for the design of new CO2RR catalysts.

Preparation and Electrochemically Catalytic Hydrogen Evolution of Co(III)corrole Copolymerized with Mono-, Bis- and Tri-Thiophenes

Preparation and Electrochemically Catalytic Hydrogen Evolution of Co(III)corrole Copolymerized with Mono-, Bis- and Tri-Thiophenes

Representative Modeling of MXene-based Hybrid Nanocomposites toward Catalytic Hydrogen Evolution Reactions: Comprehensive Review

Hydrogen can be seen not only as a renewable gas but also as an eco-friendly energy source in the future, and the demand tends to be increasing more and more....

Exploring the effect of a pendent amine group poised over the secondary coordination sphere of a cobalt complex on the electrocatalytic hydrogen evolution reaction.

A CoIII complex (2) of a bispyridine-dioxime ligand (H2LNMe2) containing a tertiary amine group in the proximity of the Co center is synthesized and characterized. One of the oxime protons of the ligand is deprotonated, and the amine group remains protonated in the solid-state structure of the CoII complex (2a). The acid-base properties of 2 showed pKa values of 5.9, 8.4, and 9.6, which are assigned to the dissociation of two consecutive oxime protons and amine protons, respectively. The electrocatalytic proton reduction of 2 was investigated in an aqueous phosphate buffer solution (PBS), revealing a catalytic hydrogen evolution reaction (HER) at an Ecat/2 of -1.01 V vs. the SHE, with an overpotential of 673 mV and a kobs value of 2.6 × 103 s-1 at pH 7. For comparison, the HER of the Co complex (1) lacking the tert-amine group at the secondary sphere was investigated in PBS, which showed a kobs of 1.3 × 103 s-1 and an overpotential of 577 mV. At pH 4, however, 2 revealed a ∼3 times higher kobs value than 1, which suggests that the protonated amine group likely works as a proton relay site. Notably, no significant change in the reaction rate was observed at different pH values for 1, implying that oxime protons may not be involved in the intramolecular proton-coupled electron transfer reaction in the HER. The kobs values for Co complexes at pH 7.0 are significantly higher than those of the [Co(dmgH)2(pyridine)(Cl)] complex, implying that the primary coordination sphere around 1 or 2 enhances the HER and offers better catalyst stability in acidic buffer solutions.

In Situ Construction of Built-In Opposite Electric Field Balanced Surface Adsorption for Hydrogen Evolution Reaction.

Achieving a balance between H-atom adsorption and binding with H2 desorption is crucial for catalyzing hydrogen evolution reaction (HER). In this study, the feasibility of designing and implementing built-in opposite electric fields (OEF) is demonstrated to enable optimal H atom adsorption and H2 desorption using the Ni3(BO3)2/Ni5P4 heterostructure as an example. Through density functional theory calculations of planar averaged potentials, it shows that opposite combinations of inward and outward electric fields can be achieved at the interface of Ni3(BO3)2/Ni5P4, leading to the optimization of the H adsorption free energy (ΔGH*) near electric neutrality (0.05eV). Based on this OEF concept, the study experimentally validated the Ni3(BO3)2/Ni5P4 system electrochemically forming Ni3(BO3)2 through cyclic voltammetry scanning of B-doped Ni5P4. The surface of Ni3(BO3)2 undergoes reconstruction, as characterized by Grazing Incidence Wide-Angle X-ray Scattering (GIWAXS) and in situ Raman spectroscopy. The resulting catalyst exhibits excellent HER activity in alkaline media, with a low overpotential of 33mV at 10mA cm-2 and stability maintained for over 360 h. Therefore, the design strategy of build-in opposite electric field enables the development of high-performance HER catalysts and presents a promising approach for electrocatalyst advancement.

Nanosized Pd@Ag heterojunction with tunable shapes: Morphological modulation for improving plasma-mediated catalytic hydrogen evolution

Catalytic ability of bi-metal hybrid nanoagents largely depends on their phase constitution and morphology, also bearing a close correlation to the fabrication process. We herein design and develop a modified polyol protocol with inorganic ion induction for rationally constructing Ag nanoagents with tunable shapes (nanowire, nanocube, and nanoparticle), followed by evenly anchoring of stepwise reduced Pd nanograins on the surface of Ag nanoagents to foster Ag core - Pd shell (i.e. Pd@Ag) nanosized heterostructure. A home-made photochemical reaction device is used to scientifically evaluate the catalytic ability of the Pd@Ag nanoagents on hydrolyzing ammonia borane to evolve hydrogen gas. The ample characterization reveals that the fabricated Ag nanoagents hold the expected regular and uniform shapes, with 10–15 nm thick Pd layer cladded on their surfaces. The particular shapes of the Ag nanoagents can be duly manipulated via the induction of inorganic ions, and the thickness and compactness of the Pd shell can also be suitably regulated by controlling reduction duration. The verified formation of electron synergistic effect among the both metals is favorable to elevate the catalytic ability. The bimetal Pd@Ag nanoagents perform the superior catalytic activity under visible light irradiation, far exceeding that of the respective monometal counterparts, with the order of catalytic activity: Pd@Ag-NWs > Pd@Ag-NCs > Pd@Ag-NPs. The hydrolysis reaction at the given conditions is confirmed to be quasi first-order reaction, with the apparent activation energy of 53.44 kJ·mol−1 and TOF value of 47.04 min−1. The Pd@Ag-NWs catalyst behaves satisfactory stability, with 87.8 % initial catalytic activity retained after five cyclic use.

Electrochemistry of and Electrocatalysis by Low-Symmetry N4 Macrocycles

The introduction of efficient and affordable catalysts for three seemingly simple electrochemical reactions could improve very much the sustainability of our energy supply: reduction of protons to hydrogen gas (the hydrogen evolution reaction, HER), water oxidation, and selective reduction of oxygen to water (the oxygen reduction reaction, ORR).1–6 Platinum group metals (PGM) are outstanding catalysts for all these reactions, but being rare and expensive prevents their utility for large scale operations.7 Within the search for catalysts based on earth abundant 1st row transition metals, we now introduce two different molecular catalysts: Co(III) complexes of corroles, with very different in size meso-C substituents (C6F5 >> CF3 >> H), as well by newly synthesized and fully characterized Co(II), Cu(II) and Ni(II) monoazaporphyrins (MAzP) with meso-CF3 substituents. All the catalyst were adsorbed on carbon supports with very different porosity (Vulcan << BP2000). The corrole-modified electrodes were studied as ORR catalysts, revealing that the onset potential of the best performing cobalt corrole is approaching that of Pt and with low percentage formation of undesired hydrogen peroxide. Testing that complex as a cathode for an anion exchange membrane fuel cell (AEMFC) revealed high power density relative to other molecular catalysts and excellent stability over 12 hours.Metal complexes of a novel MAzP with CF3 on the three meso-C positions were studied as catalysts for HER in PBS buffer (pH=7.4), as well as for water oxidation and ORR at pH 13. The cobalt complex performed best in all processes. Compared to cobalt porphyrins with either three or four CF3 groups on the meso-C positions, Co-MAzP performed better for water oxidation. For HER catalysis, it has the same onset potential and current as the tetra-CF3 cobalt porphyrin and more current than the tris-CF3 analogue. In ORR catalysis, Co-MAzP performs with the lowest onset potential, but less H2O2 is formed via catalysis by the other porphyrins.(1) Meng, J.; Lei, H.; Li, X.; Qi, J.; Zhang, W.; Cao, R. Attaching Cobalt Corroles onto Carbon Nanotubes: Verification of Four-Electron Oxygen Reduction by Mononuclear Cobalt Complexes with Significantly Improved Efficiency. ACS catalysis. 2019, pp 4551–4560.(2) Beyene, B. B.; Hung, C.-H. Recent Progress on Metalloporphyrin-Based Hydrogen Evolution Catalysis. Coord. Chem. Rev. 2020, 410, 213234.(3) Mondal, B.; Chattopadhyay, S.; Dey, S.; Mahammed, A.; Mittra, K.; Rana, A.; Gross, Z.; Dey, A. Elucidation of Factors That Govern the 2e–/2H+ vs 4e–/4H+ Selectivity of Water Oxidation by a Cobalt Corrole. J. Am. Chem. Soc. 2020, 142 (50), 21040–21049.(4) Cui, X.; Cui, Y.; Chen, M.; Xiong, R.; Huang, Y.; Liu, X. Enhancing Electrochemical Hydrogen Evolution Performance of CoMoO4-Based Microrod Arrays in Neutral Media through Alkaline Activation. ACS Appl. Mater. Interfaces 2020, 12 (27), 30905–30914.(5) Fornaciari, J. C.; Weng, L.-C.; Alia, S. M.; Zhan, C.; Pham, T. A.; Bell, A. T.; Ogitsu, T.; Danilovic, N.; Weber, A. Z. Mechanistic Understanding of PH Effects on the Oxygen Evolution Reaction. Electrochim. Acta 2022, 405, 139810.(6) Yao, B.; He, Y.; Wang, S.; Sun, H.; Liu, X. Recent Advances in Porphyrin-Based Systems for Electrochemical Oxygen Evolution Reaction. International journal of molecular sciences. 2022, p 6036.(7) Mehta, V.; Cooper, J. S. Review and Analysis of PEM Fuel Cell Design and Manufacturing. Journal of power sources. 2003, pp 32–53.

Synthesis of FeNi-based heterostructure on a nickel foam at room temperature for efficient catalyzing hydrogen evolution reaction

The FeNi-based heterostructure was synthesized on a nickel foam by a simple dip-coating method with zero-energy consumption at room temperature. The obtained heterostructure is flower-like and has high-performance for electrocatalyzing the hydrogen evolution reaction (HER). On the FeNi-based heterostructure, the overpotential was only 228 mV at a current density of 100 mA cm−2 in 1 M KOH, and can maintain 10 h stability with chronoamperometry test. The outstanding catalytic activity was attributed to the unique structure with a large electrochemical active surface area and the synergistic effect between different transition metal elements. This research afforded a new way to design low-cost and high-performance HER electrocatalyst.

Engineering Interfacial Pt─O─Ti Site at Atomic Step Defect for Efficient Hydrogen Evolution Catalysis.

The hydrogen evolution reaction (HER) activity of defect-stabilized low-Pt-loading catalysts is closely related with defect type in support materials, while the knowledge about the effect of higher-dimensional defects on the property and activity of trapped Pt atomic species is scarce. Herein, small size (5-10nm) TiO2 nanoparticles with abundant surface step defects (one kind of line defect) are used to direct the uniform anchoring of Pt atomic clusters (Pt-ACs) via Pt─O─Ti linkage. The as-made low-Pt catalysts (Pt-ACs/S-TiO2-NP) exhibit exceptional HER intrinsic activity due to the unique step-site Pi-O-Ti species, in which the mass activity and turnover frequency are as high as 21.46AmgPt -1 and 21.69s-1 at the overpotential of 50mV, both far beyond those of benchmark Pt/C catalysts and other Pt-ACs/TiO2 samples with less step sites. Spectroscopic measurements and theoretical calculations reveal that the step-defect-located Pt─O─Ti sites can simultaneously induce the charge transfer from TiO2 substrate to the trapped Pt-ACs and the downshift of d-band center, which helps the proton reduction to H* intermediates and the following hydrogen desorption process, thus improving the HER. The work provides a deep insight on the interactions between high-dimensional defect and well-dispersed atomic metal motifs for superior HER catalysis.

Synthesis of Cu2-xSe-MoSe2 Edge-Epitaxial Heterostructure for Efficient Electrocatalytic Hydrogen Evolution.

The exposure of active edge sites of transition metal dichalcogenide (TMD) in TMD-based heterostructures is essential to enhance the catalytic activity toward electrochemical catalytic hydrogen evolution (HER). The construction of TMD-based edge-epitaxial heterostructures can maximally expose the active edge sites. However, owing to the 2D crystal structures, it remains a great challenge to vertically align layered TMDs on non-layered metal chalcogenides. Herein, the synthesis of Cu2-xSe-MoSe2 edge-epitaxial heterostructure is reported by a facile one-pot wet-chemical method. A high density of MoSe2 nanosheets grown vertically to the <111>Cu2-xSe on the surface of Cu2-xSe nanocrystals is observed. Such edge-epitaxial configuration allows the exposure of abundant active edge sites of MoSe2 and enhances the changer transfer between MoSe2 and Cu2-xSe. As a result, the obtained Cu2-xSe-MoSe2 epitaxial heterostructures show excellent HER performance as compared to that of Cu2-xSe@1T/2H-MoSe2 core@shell heterostructure with similar size. This work not only offers a novel approach for designing efficient electrochemical catalysis but also enriches the diversity of TMD-based heterostructures, holding promise for various applications in the future.

Stable hydrogen evolution catalysis: Nitrogen-carbon-stabilized platinum on a microporous carbon-based framework

Hydrogen produced from water electrolysis powered by renewable energy is an environmentally friendly fuel. However, the wide commercialization of water electrolysis is hindered by the high cost and low stability of the state-of-the-art Pt/C electrocatalysts. In this work, interconnected 3D carbon-based framework with a microporous configuration supported Pt nanoparticles (Pt/rGO1-FHCNs4) was proposed, and exhibited significantly enhanced catalytic activity and stability towards hydrogen evolution. The strong metal–N interactions between Pt nanoparticles and the functionalized support kept Pt nanoparticles in a well dispersed state and modified the electron structure of platinum nanoparticles during HER. The three-dimensional structure of carbon-based supports enhanced the access of active sites to reactant. The graphene contributed to the conductivity of the catalysts. In addition, the hollow structure of the carbon support act as an efficient nano spacer and a cross-linker for the 3D assembly of graphene due to electrostatic interaction. This work provides the approaches to fabricate metal nanoparticle/3D carbon-based support composites with potential applications as high performance electrocatalysts.

Efficient hydrogen evolution from NaBH4 using bimetallic nanoparticles (Ni–Co) supported on recycled Zn–C battery electrolyte paste

Electrolytic paste (EP) from used batteries was innovatively utilized as a support for Ni–Co nanoparticles (Ni–Co NPs) to catalyze hydrogen evolution from NaBH4. The materials exhibited a porous and heterogeneous morphology, characterized by a ZnMn2O4 interplanar distance of 0.34 nm, as confirmed by SAED analysis. Elemental analysis identified carbon, nitrogen, hydrogen, and sulfur, while ICP-MS quantified zinc, manganese, and iron. XRD unveiled an amorphous broad peak at 2θ = 13.3–39.8°, with additional phases identified as ZnO, graphite, simonkolleite, manganese oxides, and hetaerolite. Raman spectroscopy showcased characteristic bands typical of carbonaceous materials. FTIR detected functional groups alongside Ni–O, Co–O, and Zn–O bonds. Various Ni/Co ratios were assessed, and the 25:75 and 20:80 (w/w) ratios showed optimal performance, yielding hydrogen at rates of 238.1 and 278.0 mL H2 gcatalyst−1 min−1, respectively. The determined activation energy was 32.76 kJ mol−1. The turnover frequency reached 1823.93 mL H2 gcatalyst−1 min−1 (328.15 K), and the catalyst exhibited satisfactory performance over 16 reuse cycles.

Atomically precise Au nanoclusters for electrochemical hydrogen evolution catalysis: Progress and perspectives

Atomically precise Au nanoclusters for electrochemical hydrogen evolution catalysis: Progress and perspectives

Atomic-level polarization in electric fields of defects for electrocatalysis

The thriving field of atomic defect engineering towards advanced electrocatalysis relies on the critical role of electric field polarization at the atomic scale. While this is proposed theoretically, the spatial configuration, orientation, and correlation with specific catalytic properties of materials are yet to be understood. Here, by targeting monolayer MoS2 rich in atomic defects, we pioneer the direct visualization of electric field polarization of such atomic defects by combining advanced electron microscopy with differential phase contrast technology. It is revealed that the asymmetric charge distribution caused by the polarization facilitates the adsorption of H*, which originally activates the atomic defect sites for catalytic hydrogen evolution reaction (HER). Then, it has been experimentally proven that atomic-level polarization in electric fields can enhance catalytic HER activity. This work bridges the long-existing gap between the atomic defects and advanced electrocatalysis by directly revealing the angstrom-scale electric field polarization and correlating it with the as-tuned catalytic properties of materials; the methodology proposed here could also inspire future studies focusing on catalytic mechanism understanding and structure-property-performance relationship.

Synthesis and characterization of magnesium zinc ferrite nanoparticles for catalytic hydrogen evolution

We have prepared Mg1-xZnxFe2O4 nanoparticles (x values varying from 0.0 to 0.8 by 0.2 increments) for use as catalysts for hydrogen production in the methanolysis of sodium borohydride (NaBH4). The catalytic performance of the Mg1-xZnxFe2O4 nanoparticles with different zinc content for hydrogen production were evaluated in the methanolysis of NaBH4 inside glass vessels. Different characterization techniques were used to analyse the prepared nanoparticles such as X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FTIR), Field Emission Scanning Electron Microscope (FESEM), Transmission Electron microscopy (TEM), and Scanning Transmission Electron microscopy STEM. The average size of Mg1-xZnxFe2O4 nanoparticles was 10 nm. The largest energy band gap value was 4.77 eV for MgFe2O4 nanoparticles, while the lowest value was 2.89 eV for Mg0.2Zn0.8Fe2O4 nanoparticles. Mg0.8Zn0.2Fe2O4 nanoparticles were proven as the catalysts with the highest hydrogeneration rate with a value of 15,957 mL min−1 g−1.

Unveiling the Synergistic Potential of Laser Chemical Solid‐Phase Deposition of Atomic Platinum‐Metal Layer on 2D Materials for Bifunctional Catalysts

AbstractThe formation of high‐density atomic metal layers on 2D materials enhances catalytic device development by providing a large surface area, precise control over active sites, and enhanced reactivity. Here, pulsed laser‐induced chemical solid‐phase deposition (LCSD) is introduced for achieving high‐density atomic metal layers. By leveraging high‐density plasma generated via pulsed nanosecond laser irradiation of thin salt layers on 2D materials, atomic‐scale metals are deposited onto abundant nucleation sites, creating dense atomic‐metal layers. This study engineers layered double hydroxide (LDH) materials layered with atomic platinum‐based alloys, exhibiting exceptional catalytic activity for overall water splitting. LDH's excellent oxygen evolution performance combined with remarkable advances in hydrogen evolution catalysis are achieved. Introducing a second element improves Pt layer dispersion and uniformity, resulting in extraordinary Pt distribution density and minimal overpotential. The LDH and Pt‐metal combination creates powerful synergistic effects, significantly enhancing catalytic performance and enabling superior bifunctional catalysts for water splitting. LCSD effectively fabricates stable nanocomposites designed for electrocatalytic applications, leveraging unique structures of atom‐scale metal‐supported composite 2D materials, enhancing overall electrocatalytic performance. This breakthrough impacts energy conversion and environmental protection, broadening electrocatalysis and revolutionizing atom‐scale metal‐supported composite 2D materials. Its practical applications span various areas, contributing to sustainable energy solutions and environmental preservation.

Mxene quantum dots bipolar electrochemiluminescent platform for hepatitis C virus envelope protein E2 detection

A burgeoning diversified closed bipolar electrochemiluminescent (d-BPE-ECL) based on photothermal amplification biosensor via the thermophysical and photochemical properties of niobium carbide Mxene quantum dots (Nb2C MQDs) has been proposed. The device consists of three components: separated intermediate recognition, cathodic catalytic hydrogen evolution reaction (HER) and anodic ECL response channel. Wherein, the recognition compartment was innovatively designed as a temperature-sensitive conductivity modulated interface, and the introduction of photothermal material PDA@Nb2C MQDs through target mediated rolling circle amplification strategy increases the interface temperature under near-infrared light radiation, thereby enhancing the BPE current and leading to the amplification of the anode ECL signal of Nb2C MQDs. In addition, MoS2@Ni–Cu–P features excellent electrocatalytic activity, which can promote HER and thus accelerate electron transfer, further amplifying the ECL signal. Therefore, a highly sensitive d-BPE-ECL biosensor for hepatitis C virus envelope protein E2 detection with a linear range from 10−4 to 10 ng/mL and detection limit of 3.3 × 10−5 ng/mL was obtained. This work is expected to provide a new direction for exploring BPE multiple signal amplification strategy and broaden the application of BPE-ECL in bioassays.

Stabilized Ti3C2Tx-doped 3D vesicle polypyrrole coating for efficient protection toward copper in artificial seawater

A closed 3D vesicle polypyrrole-based composite coating (PPy-STi) was electropolymerized on copper with the support of sodium dodecyl sulfate (SDS)-stabilized Ti3C2Tx-MXene via an inverted-electrode cyclic voltammetry route. Due to the promoted polymer nucleation effect of SDS and active catalysis of hydrogen evolution by well-dispersed Ti3C2Tx, a unique vesicle-like architecture of PPy-STi were formed with twisted diffusion pathways, which endowed a strong barrier against aggressive species. Meanwhile the stabilized Ti3C2Tx with high metallic conductivity facilitated the overall electroactivity of PPy-STi coating, yielding much improved anodic protection for copper in artificial seawater (ASW). Relying on the tolerant physical barrier and robust anodic protection capacity of PPy-STi, the coated copper could sustain its passivated state during 10 days of immersion in ASW. The integration of MXenes in conductive polymer coating with enhanced protection characteristics may provide a new strategy to improve the corrosion resistance of electronic devices in the harsh environment.

2D MoTe2 nanomesh with a large surface area and uniform pores for highly active hydrogen evolution catalysis

A kind of MoTe2 nanomesh material via nanocasting stratagem using KIT-6 silica as a hard template was synthesized. The advantage of the MoTe2 nanomesh is the large specific area (75 m2/g), a few-layer structure (3 layers), and uniform pores (5–6 nm), which effectively improves both electrocatalytic and hydrogen evolution reaction (HER) performances. Specifically, the MoTe2 nanomesh provided outstanding electrocatalytic activity with an overpotential of -300 mV for HER at -10 mA/cm2 and a small Tafel slope of 62 mV/dec. Density functional theory (DFT) calculations were investigated to optimize stable configuration and possible reaction pathways. This research provides a new insight for improving the catalytic performance of 2D TMD catalysts in electrochemical reactions.