Catalysts For Hydrogen Production Research Articles

Synergetic effects of Al addition on the performance of CoFe2O4 catalyst for hydrogen production and filamentous carbon formation from direct cracking of methane

Improving methane catalytic decomposition process was deemed an effective approach for hydrogen production. Here, a novel catalyst AlxCo1-xFe2O4 with a variable aluminum content was synthesized via a co-precipitation route for the direct cracking of methane. The catalytic activity of AlxCo1-xFe2O4 was performed in a fixed bed reactor at temperature of 800°C and 20 mL/min of fed gas. A sequence of characterizations, including SEM, BET, XRD, XPS, Raman and TGA for fresh and spent catalysts, was exploited to examine the influence of Alx content on the morphology, porosity, structure, chemical composition, and cation distribution of AlxCo1-xFe2O4. As the Alx content increased in AlxCo1-xFe2O4 their morphology became more fractal and decreased in particle size, lattice parameter, lattice size, while their pore surface increased. Further cation re-distributions from octahedral to tetrahedral sites as Fe3+ and Al3+ relocated in the Tetrahedral site and Oxygen lattice decreased as observed from Raman and XPS results. Catalytic activity studies showed that Alx content of 0.6 in AlxCo1-xFe2O4 lead maximum methane conversion up to ∼ 91.10 % and hydrogen formation rate of 1.780 ×10-3 mol H2 g-1 s-1. The catalytic activity behavior was explained in correlation with the characteristics of spent catalysts.

Mullite-like SmMn2O5-Derived Composite Oxide-Supported Ni-Based Catalysts for Hydrogen Production by Auto-Thermal Reforming of Acetic Acid.

The x%Ni/Sm2O3-MnO (x = 0, 10, 15, 20) catalysts derived from SmMn2O5 mullite were prepared by solution combustion and impregnation method; auto-thermal reforming (ATR) of acetic acid (HAc) for hydrogen production was used to explore the metal-support effect induced by Ni loadings on the catalytic reforming activity and product distribution. The 15%Ni/Sm2O3-MnO catalyst exhibited optimal catalytic performance, which can be due to the appropriate Ni loading inducing a strong metal-support interaction to form a stable Ni/Sm2O3-MnO active center, while side reactions, such as methanation and ketonization, were well suppressed. According to characterizations, Sm2O3-MnO mixed oxides derived from SmMn2O5 mullite were formed with oxygen vacancies; nevertheless, loading of Ni metal further promoted the formation of oxygen vacancies, thus enhancing adsorption and activation of oxygen-containing intermediate species and resulting in higher reactivity with HAc conversion near 100% and hydrogen yield at 2.62 mol-H2/mol-HAc.

ZnO/TiO2 heterojunction nanorod array for efficient photoelectrochemical water splitting

This study presents a novel approach utilizing a simple, stable, reproducible CV (Cyclic Voltammetry) electrodeposition method to deposit varying amounts of ZnO onto ordered TiO2 (Rutile) nanorod arrays. Comprehensive investigations were conducted on the morphology, semiconductor band-gap structure of different ZnO/Rutile composites, and their performance in photocatalytic (PC) and photoelectrochemical (PEC) hydrogen production. Results demonstrate that the ZnO/TiO2 photoanodes fabricated in this manner exhibit outstanding PC/PEC hydrogen production capabilities. Particularly noteworthy is the Z/R-15 photoanode, showcasing superior PEC performance with a photocurrent density 3.5 times higher than that of the pristine TiO2 photoanode under equivalent conditions. Furthermore, it was observed that depositing ZnO onto highly crystalline, annealed TiO2 nanorods yields optimal photoelectrical properties. Incorporating oxygen-rich vacancies in ZnO significantly enhances the photoelectrocatalytic performance of TiO2 photoanodes. The CV electrodeposition method offers valuable insights for developing efficient photocatalytic hydrogen production catalysts.

Cu-MOF modified ZnIn2S4 nanosheet composite catalyst for photocatalytic hydrogen production

In the realm of photocatalysis, the creation of clean and pollution-free composite material catalysts is critical. Electrostatic self-assembly techniques were used in this study to construct ZnIn2S4 nanosheets onto the surface of Cu-MOF, culminating in the development of a unique Cu-MOF/ZnIn2S4 composite catalyst. Cu-MOF was shown to have a strong interface impact with ZnIn2S4, which resulted in a large increase in the number of active sites and, consequently, the efficiency of hydrogen generation. This was demonstrated by a number of parameters. The Cu-MOF/ZnIn2S4-10 composite material's optimum hydrogen evolution rate was 0.3 mmol h−1g−1, which was 2.14 times larger than that of pure ZnIn2S4 nanosheets (0.14 mmol h−1g−1). Furthermore, the development of Cu-MOF/ZnIn2S4 heterojunctions considerably improved ZnIn2S4's deficiencies in photocatalytic hydrogen production, increasing charge separation rates and providing a viable approach to improve ZnIn2S4's hydrogen production efficiency.

METHANOL STEAM REFORMING FOR HYDROGEN PRODUCTION OVER Ni-BASED CATALYSTS: STATE-OF-THE-ART REVIEW AND FUTURE PROSPECTS.

With increasing global emphasis on environmental sustainability, the reliance on traditional energy sources such as coal, natural gas, and oil is encountering significant challenges. H2, known for its high energy content and pollution-free usage, emerges as a promising alternative. However, despite the great potential of H2, approximately 95% of hydrogen production still depends on non-renewable resources. Hence, the shift towards producing H2 from renewable sources, particularly through methods like steam reforming of methanol - a renewable resource - represents a beacon of hope for advancing sustainable energy practices. This review comprehensively examines recent advancements in efficient H2 production using Ni-based catalysts in methanol steam reforming (MSR) and proposes the future prospects. Firstly, the fundamental principles of MSR technology and the significance in clean energy generation are elucidated. Subsequently, the design, synthesis techniques, and optimization strategies for enhancing the catalytic performance of Ni-based catalysts are discussed. Through the analysis of various catalyst compositions, structural adjustments, surface active sites, and modification methods, the review uncovers effective approaches for boosting the activity and durability of MSR reactions.By offering a comprehensive critical analysis, this review serves as a valuable reference to enhance MSR hydrogen production efficiency and catalyst performance.

Recent Advancements in Ascribing Several Platinum Free Electrocatalysts Pertinent to Hydrogen Evolution from Water Reduction.

The advancement of a sustainable and scalable catalyst for hydrogen production is crucial for the future of the hydrogen economy. Electrochemical water splitting stands out as a promising pathway for sustainable hydrogen production. However, the development of Pt-free electrocatalysts that match the energy efficiency of Pt while remaining economical poses a significant challenge. This review addresses this challenge by highlighting latest breakthroughs in Pt-free catalysts for the hydrogen evolution reaction (HER). Specifically, we delve into the catalytic performance of various transition metal phosphides, metal carbides, metal sulphides, and metal nitrides toward HER. Our discussion emphasizes strategies for enhancing catalytic performance and explores the relationship between structural composition and the performance of different electrocatalysts. Through this comprehensive review, we aim to provide insights into the ongoing efforts to overcome barriers to scalable hydrogen production and pave the way for a sustainable hydrogen economy.

Phase-Engineered Dichalcogenides/Fluorine-Free V4C3Tx (T=OH, O) Heterostructures for pH-Universal Hydrogen Evolution Reaction.

This research addresses the pH-dependency limitation in electrocatalytic hydrogen evolution reactions (HER) by creating heterostructures through the chemical bonding between 2D-dichalcogenides and V4C3Tx (T=OH, O) planes. The one-step solvothermal synthesis employed in this study constructs a synergistically interacted 1T phase of, e.g., MoS2 and V4C3Tx MXene, demonstrating an omnidirectional improvement on catalytic stability, active site exposure, surface area enlargement, electrical conductivity, and hence enhancement of water dissociation activities. Despite the notable progress in creating hydrogen production catalysts with ground breaking performances, a significant gap remains in the availability of catalysts capable of functioning effectively under high current densities. The catalyst 1T MoS2@V4C3Tx shows remarkable activities under the current density of 1000mAcm-2, which require overpotentials of 16, 24, and 37mV in 0.5m H2SO4, 1 m KOH, and 0.1 m PBS electrolytes, respectively at 10 mA cm-2, and exhibits excellent HER performance with small overpotentials of 103.16 and 138mV to achieve current densities of 500 and 1000mAcm-2, respectively, with outstanding stability for 1000 cylic voltammetriccycle HER test without degradation in acidic media. Enhanced HER performance has also been observed in other 2D-dichalcogenides/V4C3Tx heterostructures, providing prospects for phase-engineered dichalcogenides/fluorine-free V4C3Tx composites for pH-universal HER.

Surface exsolving perovskite ceramics as catalyst for microwave methane pyrolysis to co-generate hydrogen and carbon nanotube

In this study, we have successfully developed a novel surface exsolving perovskite ceramic, which demonstrates the ability to simultaneously generate COx-free hydrogen and carbon nanotubes (CNTs) through methane pyrolysis under the influence of microwave irradiation. We conducted an extensive survey and optimization of various perovskite materials specifically tailored for microwave applications. Among the materials investigated, nickel-doped strontium titanium oxide (STON) emerged as the most promising candidate, exhibiting both a satisfactory methane conversion rate and excellent responsiveness to microwave irradiation. Refinement of STON was carried out by fine-tuning the Ni content, optimizing the reduction dwell time, and adjusting the reduction temperature. Notably, SrTiNi0.08O3 (STON8), demonstrated an impressive initial methane conversion rate of up to 40%. Transmission Electron Microscopy (TEM) provided visual evidence of the correlation between Ni content and reduction temperature, with respect to the exsolved Ni metal particle size. This finding highlights the immense potential of surface exsolving perovskite ceramics as a highly effective catalyst for the simultaneous production of CNTs and COx-free hydrogen via methane pyrolysis under microwave irradiation. It represents a step forward in the field of catalytic materials and microwave-driven processes.

A Review of the Structure–Property Relationship of Nickel Phosphides in Hydrogen Production

Hydrogen, one of the most promising forms of new energy sources, due to its high energy density, low emissions, and potential to decarbonize various sectors, has attracted significant research attention. It is known that electrocatalytic hydrogen production is one of the most widely investigated research directions due to its high efficiency in the conversion of electricity to H2 gas. However, given the limited reserves and high cost of precious metals, the search for non-precious metal-based catalysts has been widely explored, for example, transition metal phosphides, oxides, and sulfides. Despite this interest, a detailed survey unveils that the surface and internal structures of the alternative catalysts, including their surface reconstruction, composition, and electronic structure, are poorly studied. As a result, a disconnection in the structure–property relationship severely hinders the rational design of efficient and reliable non-precious metal-based catalysts. In this review, by focusing on Ni5P4, a bifunctional catalyst for water splitting, we systematically summarize the material motifs pertaining to the different synthetic methods, surface characteristics, and hydrolysis properties. It is believed that a cascaded correlation may provide insights toward understanding the fundamental catalytic mechanism and design of robust alternative catalysts for hydrogen production.

Catalytic performance of modified carbon black on methane decomposition for hydrogen production.

Carbon-based catalysts catalyze methane decomposition to produce hydrogen is a very attractive technical route. Carbon black in carbon-based catalysts has the advantages of high catalytic activity, good stability and better tolerance to toxic impurities such as sulphur in the feedstock, which has become a hot topic of research for many scientists. In this work, the effect of heat treatment on the structural and surface properties of carbon blacks and their catalytic performance in hydrogen production from methane decomposition was investigated. A commercial carbon blacks N110 was selected to heat treatment with nitrogen or carbon dioxide atmosphere at 850 °C, respectively. The Raman spectrums indicated that the graphitization degree of modified carbon under two atmospheres were promoted with the treatment time increasing. BET results revealed that the specific surface area of the carbon black treated under carbon dioxide increased, while the specific surface area was unchanged for that of the carbon black treated under nitrogen. The catalytic test of the two modified carbon blacks for methane decomposition exhibited the almost same activity, which meant that the graphitization degree of carbon black is the key factor for methane decomposition rather than the specific surface area. It was suggested that highly graphitized carbon black could be used as the potential catalysts for hydrogen production from methane decomposition.

Graphite sheet-supported bimetallic RhNi thin film alloys for enhanced and durable hydrogen evolution in acidic environments

Noble metal-based materials are excellent catalysts for hydrogen production from water electrolysis, but their high cost and limited availability hinder widespread use. However, precious metals can be effectively utilized in catalysts by forming alloys with low-cost 3d transition metals, thereby reducing the need for precious metals, while enhancing the performance. In this study, aerosol-assisted chemical vapor deposition was employed to deposit bimetallic rhodium-nickel (RhNi) alloy thin films on a graphite sheet for hydrogen evolution reaction (HER) catalysis in a 0.5 M H2SO4 solution. Thin-film morphological patterns were significantly changed as the deposition time varied from 45 to 135 min. The RhNi alloy fabricated for 90 min outperformed its counterparts, displaying lower overpotential of 40 and 197 mV at 10 and 1000 mA cm−2, small Tafel kinetics (54 mV dec−1), high conductivity (0.57 Ω) and large electrochemical surface area (3312 cm2), and extended stability (48 h) compared to pure Rh metal and other reported catalysts. The superior HER performance arises from the synergistic effects between Rh and Ni metals, coupled with a uniform layer of spherical particles that enhance conductive properties and reaction rates by providing maximized active sites on graphite surface. This work provides valuable guidelines for efficiently preparing highly active and durable thin-film electrocatalyst within short time span and applying directly in fuel cell for hydrogen production.

Shape-Preserved CoFeNi-MOF/NF Exhibiting Superior Performance for Overall Water Splitting across Alkaline and Neutral Conditions.

This study reported a multi-functional Co0.45Fe0.45Ni0.9-MOF/NF catalyst for oxygen evolution reaction (OER), hydrogen evolution reaction (HER), and overall water splitting, which was synthesized via a novel shape-preserving two-step hydrothermal method. The resulting bowknot flake structure on NF enhanced the exposure of active sites, fostering a superior electrocatalytic surface, and the synergistic effect between Co, Fe, and Ni enhanced the catalytic activity of the active site. In an alkaline environment, the catalyst exhibited impressive overpotentials of 244 mV and 287 mV at current densities of 50 mA cm-2 and 100 mA cm-2, respectively. Transitioning to a neutral environment, an overpotential of 505 mV at a current density of 10 mA cm-2 was achieved with the same catalyst, showing a superior property compared to similar catalysts. Furthermore, it was demonstrated that Co0.45Fe0.45Ni0.9-MOF/NF shows versatility as a bifunctional catalyst, excelling in both OER and HER, as well as overall water splitting. The innovative shape-preserving synthesis method presented in this study offers a facile method to develop an efficient electrocatalyst for OER under both alkaline and neutral conditions, which makes it a promising catalyst for hydrogen production by water splitting.

Computation-Driven Rational Design of Self-Assembled Short Peptides for Catalytic Hydrogen Production.

Self-assembling peptides represent a captivating area of study in nanotechnology and biomaterials. This interest is largely driven by their unique properties and the vast application potential across various fields such as catalytic functions. However, design complexities, including high-dimensional sequence space and structural diversity, pose significant challenges in the study of such systems. In this work, we explored the possibility of self-assembled peptides to catalyze the hydrolysis of hydrosilane for hydrogen production using ab initio calculations and carried out wet-lab experiments to confirm the feasibility of these catalytic reactions under ambient conditions. Further, we delved into the nuanced interplay between sequence, structural conformation, and catalytic activity by combining modeling with experimental techniques such as transmission electron microscopy and nuclear magnetic resonance and proposed a dual mode of the microstructure of the catalytic center. Our results reveal that although research in this area is still at an early stage, the development of self-assembled peptide catalysts for hydrogen production has the potential to provide a more sustainable and efficient alternative to conventional hydrogen production methods. In addition, this work also demonstrates that a computation-driven rational design supplemented by experimental validation is an effective protocol for conducting research on functional self-assembled peptides.

Investigating the potential of ZrO2/MoO3 nanocomposites for efficient hydrogen generation through NaBH4 methanolysis

This work investigates the potential of ZrO2/MoO3 nanocomposites as catalysts for hydrogen production through NaBH4 methanolysis. The samples were prepared by controlled thermal calcination and characterized using various techniques like XRD, FTIR, Raman, SEM, and surface area BET analysis. Rietveld refinements verified the presence of the ZrO2 monoclinic phase with the space group P21/c in all samples and a second orthorhombic MoO3 phase with the space group Pnma. The average crystal size decreased from 44 to 40 nm. FTIR and Raman spectroscopy confirmed the successful preparation of ZrO2/MoO3 nanocomposites. SEM analysis showed ZrO2 particles and MoO3 nanoparticles adhered to the ZrO2 surface, potentially creating a rougher texture. The results confirmed the formation of ZrO2/MoO3 nanocomposites with increasing MoO3 content, leading to an increased surface area of 19–23 m2/g. The catalytic performance evaluation revealed that the sample containing 30 % MoO3 (ZM3) exhibited the highest hydrogen generation rate of 18,451 mL/g. min at 30 °C. The calculated activation energy for ZM3 was 18.78 kJ/mol, suggesting efficient hydrogen generation at moderate temperatures.

Ce-promoted Ni-NiO small ensemble constrained in an MgO catalyst for efficient hydrogen production through NH3 decomposition

Ce-promoted Ni-NiO small ensemble constrained in an MgO catalyst for efficient hydrogen production through NH3 decomposition

Role of Mn in the Ni–Mn/SBA-15 Catalyst for Hydrogen Production by Biomass Steam Reforming at Relatively Low Temperature

Role of Mn in the Ni–Mn/SBA-15 Catalyst for Hydrogen Production by Biomass Steam Reforming at Relatively Low Temperature

Elaborate design and construction of direct Z-scheme ZnIn2S4@BiYWO6 heterojunction catalysts for efficient photocatalytic hydrogen production

Photocatalytic Hydrogen production as one of the effective ways to solve the future energy issues has recently become a research hotspot in the field of renewable energy. However, single-component photocatalysts have poor hydrogen production efficiency due to the narrow light-absorption range, susceptibility to photo-corrosion and low catalytic activity. Herein, novel heterojunction photocatalysts of ZnIn2S4@BiYWO6 with different mass ratios were designed and synthesized using a facile two-step hydrothermal method. Experimental results and analyses show that these heterojunction catalysts exhibit extremely excellent photocatalytic performance for hydrogen production. Especially, the hydrogen production rate of 10ZnIn2S4-BiYWO6 is 73 times higher than that of pure ZnIn2S4. Furthermore, enhanced photocatalytic mechanism and carrier transfer pathway in the heterojunction photocatalyst of ZnIn2S4@BiYWO6 were deeply analyzed and explored in the paper, which confirmed that ZnIn2S4@BiYWO6 is a direct Z-scheme heterojunction architecture. Within such a Z-scheme framework, the presence of a built-in electric field at the interface between ZnIn2S4 and BiYWO6 as well as the energy band bending lead to the direct recombination of electrons and holes with low redox capacity, while keeping the electrons and holes with high redox capacity in each component. Consequently, the photocatalytic activity of the Z-scheme heterojunction system has been greatly enhanced. It is believed that the present work provides valuable guidance for the design and construction of novel Z-scheme heterojunction photocatalysts.

Construction of graphdiyne/CoMoO4 type II heterojunction for efficiently enhanced photocatalytic hydrogen evolution

Cost-effective bimetallic oxide catalysts are gradually replacing noble metal catalysts for photocatalytic hydrogen production. This study used a two-step method to synthesize CoMoO4 with a rod-shaped structurea. CuBr is a catalytic base synthesis graphdiyne material. The graphdiyne that serves to anchor CoMoO4 rods through a solvent-thermal synthesis method, thereby enhancing the photocatalytic performance of the resultant composite catalyst. The results show that the 5 h hydrogen evolution capacity of the optimized CoMoO4/graphdiyne composite catalyst is 187.47 μmol, which is 2.9 times higher than that of CoMoO4 monomer and 41.7 times higher than that of graphdiyne monomer. The addition of graphdiyne provides a larger comparison area for CoMoO4, giving composite catalyst more active sites, and enhancing the optical hydrogenation effect of catalysts. Through the Mott-Schottky test, the UV–visible diffuse reflectance test and band gap calculation can be speculated that the CoMoO4 and graphdiyne construct the type II heterojunction which promotes the rapid transfer of photogonic carriers. This work provides a good prospect and opportunity for studying graphdiyne in the application of graphdiyne in the application of dualmetal oxides.

Ammonia decomposition over vanadium oxide supported Ni catalyst for hydrogen production

The performance of vanadium oxides as support is investigated to develop a new nickel catalyst for ammonia decomposition to produce hydrogen. The catalytic activity is in the order of Ni/V2O3 > Ni/VO2 > Ni/V2O5, depending on the oxidation states of vanadium oxide. The VOx supports in all of the spent catalysts are V2O3, suggesting that V2O3 is the stable phase of VOx support during the ammonia decomposition. 3 wt%Ni/V2O3 gives an ammonia conversion of 38.3% (SV = 3000 L kg−1h−1) at 530 °C. Excellent active sites with a TOF of 33.6 s−1 at 500 °C form on 3 wt%Ni/V2O3. Ni/VOx works effectively as a catalyst for ammonia decomposition to produce hydrogen.

Ameliorating the electronic environment of NiCoP by halogen doping: A strategy for boosting hydrogen evolution performance

The design of highly efficient and robust non-noble metal water splitting catalysts for hydrogen production is crucial to reduce overpotential and energy consumption. Herein, a strategy for in-situ growth of halogen-doped NiCoP (X-NiCoP/NF, X = F, Cl, and Br) catalysts with special morphology on nickel foam is proposed. Both the experimental results and theoretical calculations reveal that the downshift of the d-band center energy can regulate the charge distribution of NiCoP owing to doping of strong electronegativity halogen, thus optimizing the Gibbs free energy of H* absorption (△GH*). The F-NiCoP/NF catalyst achieves remarkable HER activity under alkaline conditions, with overpotential at 10 mA cm−2 (η10) of 59 mV and Tafel slope of 48.9 mV dec−1 in 1.0 M KOH. Moreover, F-doping significantly increases the electrochemically active surface area (ECSA) and turnover frequency (TOF), suggestive of the F promotes the formation of highly dispersed high intrinsic active sites. The F-NiCoP/NF exhibits excellent stability with a negligible decrease in activity after durability tests. This work sheds light on the facile synthesis of highly active and stable catalysts with strong electronegative atom doping for HER.