Ni Foam Catalyst Research Articles

A durable cobalt catalyst supported on Ni foam coated with Al2O3 for hydrogen generation from NaBH4 hydrolysis

A durable cobalt catalyst supported on Ni foam coated with Al2O3 (Co/Al2O3–Ni foam) is developed and analyzed using various analytical methods. In addition, the catalyst is tested to investigate the effects of the Al2O3 coating cycle, Co reduction cycle, and reaction temperature on hydrogen generation from NaBH4 hydrolysis. The Al2O3 coating cycle considerably affects hydrogen generation and the catalyst area required for a hydrogen generation rate of 1 L/min. However, the Co reduction cycle and reaction temperature slightly affect hydrogen generation and the catalyst area required for a hydrogen generation rate of 1 L/min. The catalyst exhibits an apparent activation energy of 64.3 kJ/mol, which is relatively higher than those of the other catalysts. Furthermore, the catalyst exhibits durability comparable to that of other catalysts. Thus, the Co/Al2O3–Ni foam catalyst with high apparent activation energy and comparable catalytic durability is suitable for the NaBH4 hydrogen generation system.

NiCo-Phosphide Bifunctional Electrocatalyst Realizes Electrolysis of Sugar Solution to Formic Acid and Hydrogen.

As a promising liquid hydrogen carrier, formic acid is essential for hydrogen energy. Glucose, as the most widely distributed monosaccharide in nature, is valuable for co-electrolysis with water to produce formic acid and hydrogen, though achieving high formate yield and current density remains challenging. Herein, a nanostructured NiCoP on a 3D Ni foam catalyst enables efficient electrooxidation of glucose to formate, achieving an 85% yield and 200 mA current density at 1.47 V vs RHE. The catalyst forms a NiCoOOH/NiCoP/Ni foam sandwich structure via anodic oxidative reconstruction, with NiCoOOH as the active site and NiCoP facilitating electron conduction. Additionally, NiCoP/Ni foam serves as both an anode and cathode for the production of formate and hydrogen from wood-extracted sugar solutions. At 2.1 V, it reaches a 300 mA current density, converting mixed sugars to formate with a 74% yield and producing hydrogen at 104 mL cm2 h-1 with near 100% Faradaic efficiency.

Attaining Substantially Enhanced Oxygen Evolution Reaction Rates on Ni Foam Catalysts in a Gas Diffusion Electrode Setup

Water electrolysis plays a central role in the transition to a fossil‐free society, but there are significant challenges to overcome in order to increase its availability on a large scale. Alkaline water electrolysis is a mature and scalable technology, although it has several disadvantages compared to electrolyzers working in acidic environments. In particular, the use of highly alkaline aqueous electrolytes can lead to corrosion, and the achieved current densities are relatively low. This study addresses the latter limitation by introducing a gas diffusion electrode (GDE) setup as a novel development tool that bridges the gap between research and practical applications in commercial devices such as fuel cells and electrolyzers. A high surface area Ni foam catalyst that can sustain exceptional oxygen evolution reaction (OER) current densities of up to 4 A cm−2 in a quasi‐steady‐state within our GDE setup operating in an alkaline environment is presented. The high performance of this Ni‐based benchmark catalyst is attributed to its deposition onto a mesh‐like porous transport layer (PTL) via hydrogen‐templated electrodeposition. This forms a porous foam‐like structure that augments the mass transport of the gaseous reactants at the GDE.

Multicomponent metal nanoparticles supported on nickel foam for efficient catalytic decomposition of vaporized hydrogen peroxide

Residual high-concentration vaporized hydrogen peroxide (VHP) after disinfection poses a significant threat to human health and the disinfection space. The considerable concerns make it necessary to develop efficient catalysts for VHP decomposition. In this work, three-dimensional (3D) porous Ni foam (NF)-based multicomponent nanocomposites were fabricated via a facile in-situ hydrothermal method. The effect of the composition and content of elements on the catalytic decomposition of VHP was studied. The AlCrFePt0.64/NF catalyst exhibits the best catalytic performance among all catalysts and requires only 59 min to reduce the VHP concentration from 250 ppm to 1 ppm. Furthermore, the AlCrFePt0.64/NF shows superior stability and no obvious change in VHP decomposition performance after ten recycling tests. The decomposition of VHP follows a pseudo-first-order kinetics rate law. The catalytic decomposition mechanism of VHP proceeds through O-O splitting and consecutive H-transfer reactions. The enhanced catalytic activity of the AlCrFePt0.64/NF is ascribed to the synergetic effect of noble-metal Pt and transition metals, which leads to the presence of initially larger amounts of surface O* and HO* species, and lower activation energy of the O-O bond splitting.

Pt-Coated Ni Layer Supported on Ni Foam for Enhanced Electro-Oxidation of Formic Acid.

A Pt-coated Ni layer supported on a Ni foam catalyst (denoted PtNi/Nifoam) was investigated for the electro-oxidation of the formic acid (FAO) in acidic media. The prepared PtNi/Nifoam catalyst was studied as a function of the formic acid (FA) concentration at bare Pt and PtNi/Nifoam catalysts. The catalytic activity of the PtNi/Nifoam catalysts, studied on the basis of the ratio of the direct and indirect current peaks (jd)/(jnd) for the FAO reaction, showed values approximately 10 times higher compared to those on bare Pt, particularly at low FA concentrations, reflecting the superiority of the former catalysts for the electro-oxidation of FA to CO2. Ni foams provide a large surface area for the FAO, while synergistic effects between Pt nanoparticles and Ni-oxy species layer on Ni foams contribute significantly to the enhanced electro-oxidation of FA via the direct pathway, making it almost equal to the indirect pathway, particularly at low FA concentrations.

Electrocatalytic Activity of Platinum-Nickel Layers Deposited on Nickel Foam for Formic Acid Oxidation in Acidic and Alkaline Media

The performance of direct formic acid fuel cells (DFAFCs) is greatly determined by the catalyst materials. Pt nanoparticles-based heterogeneous structures are among the most important substances for the oxidation of formic acid (FAO). In this study, Ni foam catalyst layered with platinum has been investigated as the catalyst for the oxidation of FAO in acidic and alkaline media. The catalyst has been fabricated via a two-step procedure involving the electroless deposition of the Ni layer using sodium hypophosphite as a reducing agent and subsequent electrodeposition of the platinum layer. In this work, Field Emission Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, and X-ray Diffraction have been used to characterize the morphology, structure, and composition of the prepared catalysts. The electrochemical behavior of the bare Pt, Ni/Ni foam, and PtNi/Ni foam electrodes towards the oxidation of formic acid in acidic and alkaline media was evaluated using cyclic voltammetry.It was found that the PtNi/Ni foam catalyst has a significantly higher electrochemically active surface area of Pt equal to ca. 71 cm2 than pure Pt. Moreover, the PtNi/Ni foam catalyst shows an enhanced electrocatalytic activity towards the FAO via direct pathway in both acidic and alkaline medium compared to those of Ni/Ni and pure Pt electrodes. Furthermore, the prepared PtNi/Ni foam catalyst exhibits greater tolerance of CO than the single-metal Pt in acid solution. Concomitantly, the PtNi/Ni foam catalyst is tolerant to CO poisoning n alkaline media demonstrating high poison removal ability. The PtNi/Ni foam catalyst seems to be a promising future anode material for DFAFCs.

Novel Ni foam catalysts for sustainable nitrate to ammonia electroreduction

Electrochemical nitrate reduction (NO3−RR) is considered a promising approach to remove environmentally harmful nitrate from wastewater while simultaneously producing ammonia, a product with high value. An important consideration is the choice of catalyst, which is required not only to accelerate NO3−RR but also to direct the product selectivity of the electrolysis toward ammonia production. To this end, we demonstrate the fabrication of novel Ni foam catalysts produced through a dynamic hydrogen bubble template assisted electrodeposition process. The resulting foam morphology of the catalyst is demonstrated to crucially govern its overall electrocatalytic performance. More than 95% Faradaic efficiency of ammonia production was achieved in the low potential range from –0.1 to −0.3 V vs. RHE. Hydrogen was found to be the only by-product of the nitrate reduction. Intriguingly, no other nitrogen containing products (e.g., NO,N2O, or N2) formed during electrolysis, thus indicating a 100% selective (nitrate→ammonia) conversion. Therefore, this novel Ni foam catalyst is a highly promising candidate for truly selective (nitrate→ammonia) electroreduction and a promising alternative to mature copper-based NO3−RR benchmark catalysts. Excellent catalytic performance of the novel Ni foam catalyst was also observed in screening experiments under conditions mimicking those in wastewater treatment.

Carbon coated CoO plates/3D nickel foam: An efficient and readily recyclable catalyst for peroxymonosulfate activation

Constructing of the 3D porous structured catalyst with high efficiency and low metal ion dissolution is crucial for peroxymonosulfate (PMS) based advanced oxidation technologies (AOPs). In this work, carbon coated CoO plates/3D Ni foam catalyst was prepared by hydrothermal, carbon precursor coating and subsequently carbonization method. The obtained catalyst was further applied in the activation of PMS for the degradation of ofloxacin (OFX) and other organic pollutants in water. The physicochemical properties of the catalyst were systematically characterized, and the influence of several parameters such as catalyst and PMS dosage, initial pH and temperatures on the removal of OFX were investigated. Results showed that ∼ 100% of OFX (20 mg/L) could be degraded by the catalyst within 20 min through PMS activation. Besides, the catalyst is easy to be recovered and reused with high efficiency and low metal ion leaching. The quenching experiments and the results of EPR demonstrated both free (•OH, •SO4–, O2•–) and non-free radicals (1O2) were involved in the OFX degradation, and the cycle of Co2+/Co3+ and lattice oxygen on the catalyst surface were mainly responsible for efficient reactive oxygen species (ROS) generation from PMS. Finally, intermediate products in the OFX degradation process were identified, and possible degradation pathway and the mechanism were proposed.

An Enhanced Oxidation of Formate on PtNi/Ni Foam Catalyst in an Alkaline Medium

In this study, a platinum-coated Ni foam catalyst (denoted PtNi/Ni foam) was investigated for the oxidation of the formate reaction (FOR) in an alkaline medium. The catalyst was fabricated via a two-step procedure, which involved an electroless deposition of the Ni layer using sodium hypophosphite as a reducing agent and the subsequent electrodeposition of the platinum layer. The PtNi/Ni foam catalyst demonstrated enhanced electrocatalytic activity for the FOR in an alkaline medium compared to the Ni/Ni foam catalyst and pure Pt electrode. Moreover, the PtNi/Ni foam catalyst promoted the FOR at more negative potentials than the Pt electrode. This contributed to a significant negative shift in the onset potential, indicating the high activity of the catalyst. Notably, in alkaline media with the PtNi/Ni foam catalyst, the FOR proceeds via a direct pathway mechanism without significant accumulation of poisonous carbonaceous species on the PtNi/Ni foam catalyst.

A MOF derived bifunctional electrocatalyst Ni3ZnC0.7-Mo2C with enhanced performance for overall water splitting.

The efficiency and cost of electrocatalysts are critical factors restricting their application in water electrochemical decomposition. In recent years, transition metal carbides (TMCs) have been highlighted due to their unique characteristics for water splitting: good conductivity and stability. However, their electrochemical performance required further optimization. In this work, a distinct non-solvent method was utilized to achieve a Ni3ZnC0.7-Mo2C/Ni foam (NF) catalyst, which exhibited a nanoflower structure with efficient exposed active sites. Moreover, the synergistic effect between the Mo and Ni species greatly affected its HER and OER performance. Ni3ZnC0.7-Mo2C/NF showed excellent electrocatalytic performance with small overpotentials of 58 mV and 257 mV at 10 mA cm-2 for the HER and OER, respectively. To our delight, the overall water splitting could be driven by only 1.56 V. This work not only demonstrates an excellent bifunctional electrocatalyst for overall water splitting but also provides another method for polymetallic carbide preparation and activity optimization.

Superb Ni-foam-structured nano-intermetallic InNi3C0.5 catalyst for hydrogenation of dimethyl oxalate to ethylene glycol

A high-performance Ni-foam-structured nano-intermetallic InNi3C0.5 catalyst is developed for the gas-phase hydrogenation of dimethyl oxalate (DMO) to ethylene glycol (EG). The InNi3C0.5/Ni-foam catalyst is obtainable by hydrothermal growth of NiC2O4 onto the Ni-foam, impregnation with In2O3 precursor, subsequent calcination and carburization in a syngas. Despite DMO cascade hydrogenation to MG, then to EG, and finally to EtOH, such catalyst hydrogenates DMO dexterously until to EG with a high turnover frequency of 636 h−1, because the 3Ni-In and 3Ni-C sites on InNi3C0.5(111) effectively activate DMO but hinder EG over-hydrogenation to EtOH. Favorable reaction pathway on the InNi3C0.5(111) surface predicted theoretically is DMO* → CH3OCOCO* → CH3OCOCHO* → CH3OCOCHOH* → MG* → CH3OCHOCH2OH* → CHOCH2OH* → HOCHCH2OH* → EG*. Moreover, the neutral Ni-foam diminishes the formation of ethers and diols. This catalyst achieves full DMO conversion with 96–98% EG selectivity and is stable for at least 2500 h under industrial-relevant conditions, and can also hydrogenate a broad scope of carbonyl compounds to corresponding alcohols with high yields.

The Characterisation of Hydrogen on Nickel and Cobalt Catalysts

We have investigated a series of supported and unsupported nickel and cobalt catalysts, principally using neutron vibrational spectroscopy (inelastic neutron scattering, INS). For an alumina supported Ni catalyst we are able to detect hydrogen on the metal for the first time, all previous work has used Raney Ni. For an unsupported Ni foam catalyst, which has similar behaviour to Raney Ni but with a much lower density, the spectra show that there are approximately equal numbers of (100) and (111) sites, in contrast to Raney Ni that shows largely (111) sites. The observation of hydrogen on cobalt catalysts proved to be extremely challenging. In order to generate a cobalt metal surface, reduction in hydrogen at 250–300 °C is required. Lower temperatures result in a largely hydroxylated surface. The spectra show that on Raney Co (and probably also on a Co foam catalyst), hydrogen occupies a threefold hollow site, similar to that found on Co(10bar{1}0). The reduced surface is highly reactive: transfers between cells in a high quality glovebox were sufficient to re-hydroxylate the surface.

Electrocatalytic reforming of waste plastics into high value-added chemicals and hydrogen fuel.

The upcycling of waste plastic offers an attractive way to protect the environment and turn waste into value-added chemicals and H2 fuel. Herein, we report a novel electroreforming strategy to upcycle waste polyethylene terephthalate into high value-added chemicals, such as terephthalate and carbonate, over a Pd modified Ni foam catalyst. This system exhibits excellent electrocatalytic activity (400 mA cm-2 at 0.7 V vs. RHE) and high selectivity (95%)/faradaic efficiency (93%) for the product carbonate. Our work demonstrates a technology that can not only transform waste polyethylene terephthalate into value-added chemicals but also generate H2 fuel via an all-in-one electro-driven process.

Self-supported Ni3Se2@NiFe layered double hydroxide bifunctional electrocatalyst for overall water splitting

Low-cost, highly active and earth-abundant bifunctional electrocatalyst is very important for the large-scale hydrogen production by water splitting. In the present work, we report a novel two-step method to fabricate three-dimensional (3D) porous catalyst for water splitting. The Ni3Se2 nanowires are in-situ formed on Ni foam (NF) by simple hydrothermal method, subsequently NiFe layered double hydroxid (NiFe-LDH) nanosheets vertically grow on the nanowires to form core-shell structure. The as-formed Ni3Se2@NiFe-LDH/NF catalyst shows 3D porous structure, which can provide large specific surface area and effective substance transfers. The tight bonding between Ni3Se2 nanowires and NiFe-LDH nanosheets ensures good electron transfer. The Ni3Se2@NiFe-LDH/NF catalyst exhibits outstanding electrocatalytic property for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in an alkaline medium. The overpotentianls for HER and OER at the current density of 10 mA cm−2 in 1 M KOH are 68 mV and 222 mV, respectively. For overall water splitting, a small cell voltage of 1.55 V can achieve a current density of 10 mA cm−2 in 1 M KOH. This work provides a guidance for the rational design and development of heterostructure electrocatalysts for overall water splitting.

The preparation and performance of a novel spherical spider web-like structure Ru Ni / Ni foam catalyst for NaBH4 methanolysis

Abstract In this work, a spherical spider web-like structure Ru Ni/Ni foam catalyst was prepared for hydrogen evaluation from sodium borohydride (NaBH4) by a combination of electroless plating and electroplating. Microstructure, surface morphology, surface area and elemental composition of the Ru Ni/Ni foam catalyst were analyzed by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM-EDS and X-ray Photoelectron Spectroscopy (XPS), Brunauere-Emmette-Teller method (BET, AS-1C-VP), respectively. The influences of Ru Ni with different molar ratios, NaOH concentration, NaBH4 concentration, and solution temperature on the hydrogen production rate were investigated in this paper. The results showed that the Ru Ni metals were arrayed densely and uniformly on the surface of Ni foam. The average hydrogen production rate is 360 mL min −1 g−1 in 20 wt % of NaBH4, 1 wt% of NaOH at 30 °C in the presence of the Ru Ni/Ni foam catalysts. The calculated activation energy was 39.96 kJ mol−1 for hydrogen production from sodium borohydride using the Ru Ni/Ni foam catalyst.

A highly efficient 2D siloxene coated Ni foam catalyst for methane dry reforming and an effective approach to recycle the spent catalyst for energy storage applications

An effective approach to reuse the carbon deposited spent catalyst (siloxene/Ni foam) after the methane dry reforming process is demonstrated by utilizing them as electrodes for supercapacitor devices.

Highly Dispersed Platinum on Honeycomb-like NiO@Ni Film as a Synergistic Electrocatalyst for the Hydrogen Evolution Reaction.

Platinum (Pt) is well-known as the best-performing catalyst for the hydrogen evolution reaction (HER), but its practical application is severely hindered by its prohibitively high cost and problematic performance in alkaline electrolyte. Herein, we report that the issues of intrinsic activity and cost concern of Pt can be simultaneously addressed by employing a combination of concerted catalysis and nanoengineering strategies. Motivated by our density functional theory (DFT) calculations that the cooperative catalysis between Pt and NiO would lead to a better HER activity in comparison to Pt solely in alkaline solution, we successfully synthesized a Pt/NiO@Ni/NF nanocomposite catalyst by depositing highly dispersed Pt nanoclusters/nanoparticles on a honeycomb-like NiO@Ni film supported on Ni foam (NF). The resulting Pt/NiO@Ni/NF catalyst outperforms the commercial Pt/C catalyst with a high and stable HER activity in alkaline solution and, more impressively, with an economical Pt content as low as ∼0.1 mg cm-2.

Octopus tentacles-like WO3/C@CoO as high property and long life-time electrocatalyst for hydrogen evolution reaction

Enlarging the specific surface area and increasing the number of active sites of catalysts have been the key factors to improve the properties of hydrogen evolution reaction (HER) catalysts. Herein, we report a novel remarkable octopus tentacles-like tungsten oxide and carbon coated cobalt oxide (WO3/C@CoO) catalyst on Ni foam (NF) for HER at the first time, which is synthesized via simple hydrothermal process and immersion method. The obtained Ar/H2-treated WO3/C@CoO/NF catalyst exhibits excellent electrocatalytic activity toward HER with an onset potential of 40 mV (vs. RHE) and a Tafel slope of 115 mV dec−1 in 1 M KOH, which is significantly better than the Ar-treated WO3/C@CoO/NF and the CoO/NF NWs. In addition, the prepared Ar/H2-treated WO3/C@CoO/NF electrode has an outstanding electrocatalytic durability in a long period of stability test for 110 h. Such outstanding property of the Ar/H2-treated WO3/C@CoO/NF electrocatalyst is attributed to its 3D conductive substitute, carbon coating, strong synergistic effect of between WO3 and CoO and the unique octopus tentacles-like structure making it a very excellent catalyst for hydrogen production. All these experimental results clearly suggest that Ar/H2-treated WO3/C@CoO/NF electrocatalyst can improve HER catalytic activity and thus has potential practical applications in water splitting.

Constructing hierarchical mushroom-like bifunctional NiCo/NiCo2S4@NiCo/Ni foam electrocatalysts for efficient overall water splitting in alkaline media

Electrochemical water splitting into hydrogen energy offers a promising pathway for renewable and clean energy conversion and storage, but high overpotentials are needed to drive the process owing to the sluggish kinetics of the anodic oxygen evolution reaction (OER) and the cathodic hydrogen evolution reaction (HER). Herein, three-dimensional (3D) mushroom-like NiCo/NiCo2S4@NiCo arrays grown directly on Ni foam (NF) have been constructed via hydrothermal and electrodeposition methods. Owing to the unique mushroom-like structure and the beneficial effect of the composite catalyst, the NiCo/NiCo2S4@NiCo/NF electrode exhibits excellent activity and stability for both OER and HER. When serving as an anode electrocatalyst, the composite catalyst only requires a overpotential of 294 mV to achieve a high current density of 100 mA/cm2 for the OER in 1 M KOH. Moreover, in chronopotentiometric and chronoamperometric measurements, the NiCo/NiCo2S4@NiCo/NF electrode displays distinguished electrochemical and structural stability for at least 100,000 s. Similarly, the NiCo/NiCo2S4@NiCo/NF catalyst delivers a hydrogen production current density of 10 mA/cm2 at an overpotential of 132 mV and shows no obvious attenuation of performance after stability testing for 100,000 s in an extreme alkaline environment. Accordingly, the remarkable and stable bifunctional abilities enable the application of the NiCo/NiCo2S4@NiCo/NF catalyst in two-electrode water-alkali electrolyzers with a low cell voltage of 1.55 V to deliver a current density of 10 mA/cm2 and excellent stability for over 27 h.

Oxidative dehydrogenation of ethane to ethylene: A promising CeO2-ZrO2-modified NiO-Al2O3/Ni-foam catalyst

From macro- to nano-engineering of a promising CeO2-ZrO2-doped NiO-Al2O3/Ni-foam catalyst has been demonstrated for the oxidative dehydrogenation of ethane to ethylene (ODE), through facial wet chemical etching of a Ni-foam followed post modification with CeO2 and ZrO2. The NiO-Al2O3/Ni-foam (denoted as NANF) achieved a high ethane conversion of 25.2% but with a very low ethylene selectivity of 43.1% at 450°C. ZrO2-doping of the NANF led to a remarkable improvement in the ethylene selectivity but serious deterioration of activity while the CeO2-doping showed an opposite effect. Co-doping of the NANF using optimal amount of CeO2 and ZrO2 markedly promoted not only the activity but also the selectivity to ethylene. For example, over the 1CeO2-5ZrO2-NANF (CeO2:1wt%, ZrO2:5wt%) catalyst, a high ethane conversion of 40.3% was obtained with a 60.6% ethylene selectivity for a feed gas of C2H6/O2/N2=1/1/8 at 500°C and a gas hourly space velocity of 18,000cm3g−1h−1, corresponding to a high ethylene productivity of 510gEthylenekgcat−1h−1. In nature, co-doping with CeO2 and ZrO2 synergistically tamed the NiO for selective H-abstraction of the ethane molecules other than over oxidation of them.