Catalysts For Hydrogen Production Research Articles

Pulse-reverse electrodeposited reduced graphene oxide electrode decorated by Ni-P porous nano-layer as a high performance electrocatalyst for H2 production assisted by hydrazine electrooxidation

Replacing the sluggish oxidation reaction in water-splitting process with the relatively fast anodic reaction is an effective method for producing H2. Here, we designed an amorphous Ni-P/rGO/NF nano-microporous catalyst for fast and easy hydrogen production from water splitting assisted by hydrazine electrooxidation reaction (HzOR). Cathodic cyclic voltammetry electrodeposition of Ni-P on rGO/NF electrode results in a nano-micro porous structure with superior conductivity besides excellent stability and catalytic activity toward both HzOR and HER. The electrode due to the specific structure and surface morphology, shows excellent electrocatalytic activity achieves 10 and 100 mA cm−2 at − 117, and − 82 mV for HER and 127 and 7.34 mV for HzOR, respectively. Furthermore, the optimized electrode demonstrated high retention rates of 97.4%, and 94.8% towards HER and HzOR, respectively. In a two-electrode cell, a small cell voltage of 241 mV is required to touch a current density of 100 mA cm−2.

Anti-coking Cu-Ni bimetallic catalyst for hydrogen production: Thermodynamic and experimental study of methanol autothermal reforming

Autothermal reforming has emerged as a promising route for hydrogen production from bio-methanol, offering a balance between hydrogen production and the energy demand of the process. To address the low catalytic performance of non-precious metal catalysts, one of the approaches is to introduce a second metal. In this work, a series of Cu-Ni bimetallic catalysts derived from Ca-Al hydrotalcite-like compounds were prepared by the urea hydrolysis method combined with hydrothermal treatment, featuring well-dispersion with a size of 3-5 nm. The electron redistribution triggered by the incorporation of Cu enhances the absorption of methanol at the electron-poor surface, leading to maintained catalytic activity at 450°C for 96 hours with few carbon-deposition observed for methanol autothermal reforming. The boundary conditions of the thermal-neutrality system are analyzed by thermodynamic calculations and similar trends to the simulation results were also obtained from experiments.

A DFT study of ethanol interaction with the bimetallic clusters of PtSn and its implications on reactivity

The comprehension of the factors affecting the adsorption of ethanol over metals and metal alloys is a crucial step for the rational development of new catalysts for hydrogen production through ethanol reforming. In this work, we analyze the effect of combining Pt and Sn on a metal cluster on the complexation energy and reactivity for OH dehydrogenation of ethanol. Metal clusters of Pt10, Sn10 and Pt5Sn5 had their putative minimum located with the help of the artificial bee colony algorithm. Whereas the isolated Pt cluster shows a high degree of polarization (ESP surface), the Sn cluster shows a quite uniform electron density surface. The PtSn cluster is strongly polarized, with Pt atoms withdrawing electron density of Sn atoms. Complexation occurs with the oxygen atom of ethanol directed towards the point of highest electron potential in the ESP surface. Pt presents the highest complexation energy, −20.90 kcal/mol, against only −7.83 kcal/mol (at the B97-3c level). For the PtSn cluster, the value is intermediate, namely −12.39 kcal/mol. The more malleable electron density of Pt and its electron affinity are responsible for its highest complexation energy. These characteristics are partially transferred to the PtSn cluster. QTAIM results show that, for the PtSn cluster, the O–H bond in ethanol is somewhat weaker than for pure Pt and Sn. As a consequence, the energy barrier for the O–H dehydrogenation has its lowest value for the PtSn cluster, which shows that the alloying of two metals can lead to quite quite unexpected results opening the perspective for a more rational fine tuning of catalysts properties.

Fe–Al core-shell structure as an efficient catalyst for dual hydrogen production and storage by thermochemical water splitting: A reactive molecular dynamic simulation

Catalysts with dual functions in hydrogen production and storage are desired for the low-cost technology. In the preceding view, we used reactive force molecular dynamics to demonstrate how effective the Fe–Al core-shell structure is at breaking up water molecules and storing hydrogen free radicals via thermochemical water splitting. The results show that at T ∼600 K, water molecules begin to dissociate in the presence of a Fe–Al catalyst, releasing OH and H free radicals. It is worth noting that the produced OH free radicals are bonded to the Al-shell, whereas the H free radicals move to the Fe-core and stores via chemical bond. Interestingly, at T < 1200 K, there is no Fe–O bond. This could be due to Al having a higher oxidation potential than Fe, causing OH free radicals to preferentially associate with the Al-shell. Furthermore, at 2000K < T > 3000 K, the number of Fe–H bonds decreases while the number of H–H bonds increases, indicating that the stored H atom desorbs and forms an H2 molecule. Temperature can thus be used to monitor the ability of Fe–Al catalysts to dissociate water, store hydrogen, and produce hydrogen. This research shows that developing core-shell type catalysts can provide an effective solution for hydrogen generation, storage, and transportation.

An efficient electrocatalytic catalyst for hydrogen production: MoS2/Cu2S/PANI with 'wheat ear' structure

An efficient electrocatalytic catalyst for hydrogen production: MoS2/Cu2S/PANI with 'wheat ear' structure

Synthesis of Copper/Sulfur Co-Doped TiO2-Carbon Nanofibers as Catalysts for H2 Production via NaBH4 Hydrolysis

Copper/sulfur co-doped titanium dioxide-carbon nanofibers (Cu,S-codoped TiO2 NPs, decorated-CNFs) catalysts were synthesized using the electrospinning process to produce composite nanofibers (NFs). These composite NFs were utilized for the hydrolysis of sodium borohydride (SBH) to generate hydrogen gas (H2), taking advantage of their catalytic properties. The experimental results demonstrated that using 100 mg of composite NFs yielded the highest catalytic activity for H2 production, generating 79 mL of H2 gas within 6 min at 25 °C and 1000 revolutions per minute (rpm) using 1 mmol of SBH. As the catalyst dosage was reduced from 100 mg to 75, 50, and 25 mg, the reaction time increased by 9, 13, and 18 min, respectively. Kinetic studies revealed that the reaction rate followed a first-order reaction, indicating a direct proportionality between the rate of reaction and the catalyst amount. Additionally, it was observed that the concentration of SBH had no influence on the reaction rate, suggesting a zero-order reaction. Increasing the reaction temperature resulted in a reduced reaction time. The activation energy was determined to be 26.16 kJ mol−1. The composite NFs maintained their superior performance over five iterations. These findings suggest that composite nanofibers have the potential to serve as a cost-effective alternative to expensive catalysts in hydrogen production.

Ternary NiMo-Bi liquid alloy catalyst for efficient hydrogen production from methane pyrolysis.

Methane pyrolysis (MP) is a potential technology for CO2-free hydrogen production that generates only solid carbon by-products. However, developing a highly efficient catalyst for stable methane pyrolysis at a moderate temperature has been challenging. We present a new and highly efficient catalyst created by modifying a Ni-Bi liquid alloy with the addition of Mo to produce a ternary NiMo-Bi liquid alloy catalyst (LAC). This catalyst exhibited a considerably low activation energy of 81.2 kilojoules per mole, which enabled MP at temperatures between 450 and 800 Celsius and a hydrogen generation efficiency of 4.05 ml per gram of nickel per minute. At 800 Celsius, the catalyst exhibited 100% H2 selectivity and 120 hours of stability.

Modulating adsorption energy on nickel nitride-supported ruthenium nanoparticles through in-situ electrochemical activation for urea-assisted alkaline hydrogen production

The rational design of electrocatalysts with exceptional performance and durability for hydrogen production in alkaline medium is a formidable challenge. In this study, we have developed in-situ activated ruthenium nanoparticles dispersed on Ni3N nanosheets, forming a bifunctional electrocatalyst for hydrogen evolution and urea oxidation. The results of experimental analysis and theoretical calculations reveal that the enhanced hydrogen evolution reaction (HER) performance of O-Ru-Ni3N stems primarily from the optimized hydrogen adsorption and hydroxyl adsorption on Ru sites. The O-Ru-Ni3N on nickel foam (NF) electrode exhibits excellent HER performance, requiring only 29 mV to reach 10 mA cm−2 in an alkaline medium. Notably, when this O-Ru-Ni3N/NF catalyst is employed for both HER and urea oxidation reaction (UOR) to create an integrated H2 production system, a current density of 50 mA cm−2 can be generated at the cell voltage of 1.41 V. This report introduces an energy-efficient catalyst for hydrogen production and proposes a viable strategy for anodic activation in energy chemistry.

In Situ Preparation of 2D Co-B Nanosheets@1D TiO2 Nanofibers as a Catalyst for Hydrogen Production from Sodium Borohydride

In this study, 2D Co-B nanosheet-decorated 1D TiO2 nanofibers (2D Co-B NS-decorated 1D TiO2 NFs) are synthesized via electrospinning and an in situ chemical reduction technique. The as-prepared catalyst showed excellent catalytic performance in H2 generation from sodium borohydride (SBH). When compared to naked Co-B nanoparticles, the catalytic activity of the 2D Co-B NS-decorated 1D TiO2 NFs catalyst for the hydrolysis of SBH is significantly enhanced, as demonstrated by the high hydrogen generation rate (HGR) of 6020 mL min−1 g−1 at 25 °C. The activation energy of hydrolysis was measured to be 30.87 kJ mol−1, which agreed with the reported values. The catalyst also showed good stability. Moreover, the effects of SBH, catalyst concentration, and temperature on the catalytic performance of 2D Co-B NS-decorated 1D TiO2 NFs were studied to gain a comprehensive understanding of the dehydrogenation mechanism of SBH. Based on these findings, we conclude that 2D Co-B NS-decorated 1D TiO2 NFs are effective catalytic materials for the dehydrogenation of SBH.

Ammonia decomposition over Ru-coated metal-structured catalysts for COx-free hydrogen production

We report the development of Ru/Mg–Al oxide coated metal-structured catalysts with excellent heat and mass transfer characteristics for efficient clean H2 production from ammonia decomposition. Ammonia is a promising carrier for the mass transport of hydrogen and facilitates the production of COx-free hydrogen by decomposing into nitrogen and hydrogen. Ru nanoparticles are uniformly dispersed on the Mg–Al oxide layer of the FeCralloy monoliths and foams via precipitation. The catalytic activities depend on the surface area and loading of the catalysts and the metal dispersion in the oxide layer. At temperatures <650 °C, and a gas hourly space velocity (GHSV) of 3,000 h−1, monolithic catalysts with a large surface area and evenly distributed active metals perform excellently. Foam catalysts with excellent heat transfer performance better at temperatures >650 °C and GHSV >6,000 h−1. Foam catalyst stability is verified for 100 h in a 20 Nm3/h high-purity hydrogen production system.

CuO–ZnO catalyst decorated on porous CeO2-based nanosheets in-situ grown on cordierite for methanol steam reforming

Development of efficient and durable structured catalysts for hydrogen production by methanol steam reforming (MSR) is becoming extremely appealing owing to their low pressure drop and large open area. In this work, porous CeO2-based nanosheet array is in-situ grown on the surface of cordierite honeycomb ceramic by a simple hydrothermal approach. The generated porous nanosheet structure not only surpasses the obstacle of low specific surface area of cordierite (increasing from 4.4 to 252.6 m2 g-1), but also the peak area ratio of oxygen vacancies on the support surface rises from 19.7% to 29.7%, which are favorable to promote the catalytic activity and reduce by-product CO selectivity of structured catalysts in MSRreaction. Importantly, the structured catalysts formed by decorating CuO–ZnO catalysts on CeO2-based nanosheets via sol-gel combustion method remain porous structure, offering an ideal space for reactant entry and mass transfer diffusion, which facilitates reaction triggering and product discharge. The optimal structured catalyst achieves 100% methanol conversion at 260 °C without CO and the methanol conversion remains at 94.7% after 100 h of the reaction, exhibiting the excellent catalytic activity and durability. Thus, the structured catalyst has potential for industrial-scale preparation and application, especially for on-site hydrogen production in vehicles.

Enhancing the catalytic performance and coke reduction using low-cost Ni-based promoted catalyst for hydrogen production

Dry reforming of methane (DRM) is a highly promising reforming technology that facilitates converting CO2-rich natural gas into synthesis gas. However, the commercial application of DRM has concerns such as carbon deposition and sintering of the catalyst at high temperatures, leading to catalyst deactivation. This study aimed to determine the effect of an alkaline promoter addition on the amount of carbon deposited and activity test of alkaline-promoted nickel-based catalysts. Alkaline-promoted nickel-based catalysts were prepared using the incipient wetness impregnation method, followed by characterization using X-ray diffraction, N2 physisorption, H2-TPR, CO2-TPD, and thermogravimetric analysis. The performances of the catalysts were tested in a fixed-bed reactor under atmospheric pressure at 700 °C for 240 min. The Mg-promoted catalyst yielded the highest CH4 conversion (78%), CO2 conversion (64%), and H2 to CO ratio (1.52) compared to the non-promoted nickel-based and other alkaline-promoted catalysts. Furthermore, the thermogravimetric analysis revealed the Mg and Na-promoted catalyst produced 1.2 and 3.5 times less carbon than a commercial steam reforming catalyst.

Carbon-doped mesoporous TiO2-immobilized Ni nanoparticles: Oxygen defect engineering enhances hydrogen production

Constructing efficient, durable, and economical catalysts to promote hydrogen production from hydrous hydrazine (N2H4·H2O) is crucial, but still a great challenge. Herein, noble-metal-free Cr(OH)3-modified Ni nanoparticles (NPs) (2.7 nm) supported on defect-rich carbon-doped mesoporous TiO2 nanosheets (C-TiO2) were prepared for the first time via a simple and green wet-chemistry approach, in which the amount of oxygen defect in C-TiO2 can be easily regulated by adjusting the amount of carbon doping. Significantly, the defect rich Ni-Cr(OH)3/C-TiO2 catalyst presented 100% H2 selectivity, ultrahigh catalytic activity, and remarkable durability for N2H4·H2O dehydrogenation, with a turnover frequency (TOF) value of 266 h−1 at 323 K, more than 6-fold improvement than that of the Ni-Cr(OH)3/TiO2 (41 h−1), which is among the highest values reported so far for noble-metal-free catalysts. The superior catalytic efficiency and durability are mainly owing to the small-sized and electron-rich of Ni NPs induced by the oxygen defects in C-TiO2, where the more oxygen defects, the better the catalytic activity. Furthermore, the catalyst also showed outstanding catalytic efficiency (TOF = 577 h−1) and robust durability for complete dehydrogenation of hydrazine borane (N2H4BH3) at 323 K. This work provides inspiration for the construction of defect engineering and new insights for the development of low-cost and efficient heterogeneous hydrogen production catalysts.

Highly-efficient hydrogen production from ammonia decomposition over Co-doped graphdiyne under moderate temperature

Manufacturing hydrogen from ammonia decomposition is an efficient and promising approach for hydrogen utilization. However, its scalable application is significantly impeded by the requirements of precious metal ruthenium (Ru) as catalysts. Herein, we report a type of Co-doped graphdiyne catalyst for catalytically decomposing ammonia (NH3) to generate H2. The metal-doped graphdiyne catalysts were synthesized facilely using co-precipitation approach. The resultant composite catalysts significantly enhanced the reactivity and stability of ammonia decomposition. The Co-doped graphdiyne catalyst achieved nearly complete decomposition of ammonia at 550 ℃, and the conversion rate remained stable over 18 h of continuous reaction. The adsorption and decomposition of ammonia by Co-doped graphdiyne was studied by density functional theory (DFT) calculations. Nitrogen binding strength was used as a descriptor to elucidate the catalyst's activity and reaction kinetics, further supported by the reaction energy barrier. Our study highlights the tremendous potential of metal-doped graphdiyne catalysts for facile hydrogen production via NH3 decomposition, enabling safe and scalable hydrogen utilization.

Organic catalysts for hydrogen production from noodle wastewater: Machine learning and deep learning-based analysis

Hydrogen production from the electrolysis of wastewater is an environmentally friendly and highly efficient process. The performance of this process for instant noodle wastewater is strongly influenced by covering the PVC sheet with different arrangements of antioxidant-containing protein (ACAP) as an organic catalyst. However, analyzing this process through traditional models and experimental studies takes time, money, and effort. In the present research, several machine learning-based models, including the recurrent neural network (RNN), the least absolute shrinkage and selection operator (LASSO), the extreme gradient boosting (XGBoost), the linear regression (LR), and the light gradient-boosting machine (LightGBM) were developed to accurately predict hydrogen production performance from the electrolysis of noodle wastewater. Several materials have been studied in this research, such as Car, Car-Tur, Tur-Car, Tur, Car-Ver-Tur, and Car-Tof-Ver in the 12-V and 24-V states. For each material created, the LASSO regression and the linear regression formula include 12 formulas (six formulas for each state) for hydrogen production. The R-Squared values range between 0.989 and 0.997 for the six formulas by the polynomial form and by the XGBoost and the lightGBM making the six models for the hydrogen production, and the R-Squared values for all models are 0.999 by linear form for the hydrogen production in the 24-V state. For the hydrogen productions in the 12-V state, the values of the R-Squared range between 0.995 and 0.998 by the polynomial form. Using the lightGBM and the XGBoost, six models are made in linear form, and all of those models' R-Squared values are 0.999. Using the RNN algorithm can predict the future of each material's hydrogen production.

Estimation of the Efficiency of Oxalic Acid in the Solution Combustion Synthesis of a Catalyst for Production of Hydrogen and Carbon from Methane

Estimation of the Efficiency of Oxalic Acid in the Solution Combustion Synthesis of a Catalyst for Production of Hydrogen and Carbon from Methane

A New Approach to the Preparation of Stable Oxide-Composite Cobalt–Samarium Catalysts for the Production of Hydrogen by Dry Reforming of Methane

A new approach to preparing a series of Co/Sm2O3 catalysts for hydrogen production by the dry reforming of methane has been developed. The catalyst precursors were synthesized with a simple method, including the evaporation of aqueous solutions of cobalt and samarium nitrates, followed by a short-term calcination of the resulting material. The as-prepared and spent catalysts were characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, temperature-programmed reduction, and thermogravimetric analysis. The content of cobalt in the synthesized materials affects their phase composition and carbonization resistance in the dry reforming of the methane reaction. It has been shown that preheating in N2 atmosphere produces catalysts that provide a stable yield of hydrogen and CO of 94–98% for at least 50 h at 900 °C. These yields are among the highest currently available for the dry reforming of methane catalysts made from Co-Sm complex oxides. It has been established that the decrease in the amount of cobalt in the catalyst and its preheating to an operating temperature of 900 °C in a nitrogen flow help to prevent the carbonization of the catalyst and the sintering of metal particles.

Zn-incorporated joule-heated carbon nanofiber aerogel-supported Cu catalyst for hydrogen production via methanol steam reforming

Conventional Cu-based catalysts are affected by disadvantages, such as uneven temperature distribution, non-uniformity of mass and heat transfer, slow heating rate, and difficult replacement. To address these, a three-dimensional (3D) Zn-incorporated Joule-heated carbon nanofiber aerogel (CNFA)-supported Cu catalyst, was prepared via a facile one-pot method. The optimized catalyst, Cu10–Zn10/CNFA, exhibited an 83.1% conversion of CH3OH and 0.01% selectivity of CO at 250 °C. This improvement was due to Zn species acting as both an isolating agent, which inhibited thermal transmigration and aggregation of Cu-containing nanoparticles during heat treatment, and a combining agent, which provided numerous Cu–ZnO interfaces that enabled strong interactions between Cu and ZnO, which improved the activity and stability of the methanol steam reforming (MSR) reaction. This study reveals the feasibility of utilizing Joule-heated CNFA-supported catalysts for MSR reactions and opens a new avenue for designing and fabricating 3D-ordered porous catalysts related to this transformation.

Effect of calcium and potassium on activity of mordenite-supported nickel catalyst for hydrogen production from biomass gasification

This research shows the effect of a catalyst supported on mordenite (natural and modified) impregnated with nickel, calcium, and potassium on palm kernel shell gasification for hydrogen production. The gasification process was carried out using a lab-scale fixed bed reactor at 900 °C with steam as gasifying agent. The use of the catalysts significantly improved the hydrogen production and the incorporation of metals in the mordenite increased hydrogen selectivity. The maximum H2 content in the non-catalyzed gasification was approximately 34 mol%, while in the treatments with catalysts it ranged between 40 and 73 mol%. The T2-C5 catalyst impregnated with Ni, Ca, and K presented the highest H2 content (72.9 mol%), which is associated with the synergistic interaction of nickel, calcium, and potassium. This catalyst presented the highest strong acidity (1.30 mmol NH3 g−1) and the highest crystallinity (85.8%) compared to the other catalysts, properties that influenced the catalytic performance.

Enhanced machine learning for nanomaterial identification of photo thermal hydrogen production

Instead of using temperature via an outside source, using energy created inside is the most effective method to improve the efficiency of catalysis. In this research, a novel hollowed TiO2 photothermal nano catalyst (referred to as RuO2/TiO2/Pt/Carbon) for enzymatic production of hydrogen under ultraviolet irradiation is used. It resembles a hedgehog and contains regionally dispersed Pta and RuO2 double co-catalysts. The ultraviolet (UV) thermos kinetic efficacy of the converters that were made was evaluated according to architectural characteristics and the heat influence of the carbon-based surface. There are several inherent benefits for photocatalysis with heterogeneity exist in multi-layered hollowed hetero structures having extremely thin two-dimensional (2D) nanosheet subunits of the including improved sunlight gathering, accelerated separation of charged particles and disposal, and accelerated interface oxidation reactions. The sandwich-like nanotechnology of the charcoal layer, silver tiny particles, and TiO2 surface effectively supports and protects Pt Micro particle against the accumulation and breaking down of Platinum sites that are active. Moreover, the electricity production of the reaction involving hydrogen evolution is nonetheless in its infancy, and there is tonnes of untapped potential for the use of Machine Learning (ML). The following perspective focuses on new developments in the detection of outstanding performance Hydrogen Evolution Reaction (HER) catalysts using Artificial Intelligence (AI) in an effort to stimulate more broad proposals for research. In the course of the research, an Artificial Neural Network (ANN) strategy was created and validated in order to forecast the results of the hydrogen assessment. The analysis of the dataset's test results demonstrates that the ANN technique can reliably and accurately estimate the generation of hydrogen.