Inexpensive Catalyst Research Articles

Tandem Synthesis of Benzylidenemalononitrile Derivatives in/on Water under Visible Light

AbstractTandem processes are valuable tools that allow to build molecular complexity while reducing waste production and the number of steps of synthetic routes. In this work, the in situ photooxidation of benzyl alcohols to the corresponding benzaldehydes is coupled with a Knoevenagel condensation for the preparation of benzylidenemalononitrile derivatives. In this rapid one‐pot tandem process, sodium anthraquinone‐1,5‐disulfonate (SAS) and β‐alanine are employed as safe and inexpensive catalysts, while air is used as a terminal oxidant. Moreover, using water as reaction medium results in most cases in the precipitation of the target products, thus facilitating their isolation.

Graphitized carbon-anchored FeSe nanoparticles for stable and efficient bifunctional electrocatalyst in rechargeable zinc-air batteries

Developing zinc-air batteries still heavily relies on the design of stable, high-activity, and inexpensive oxygen-electric bifunctional catalysts. In this work, transition metal iron salts converted amorphous carbon into graphitized carbon at high temperatures, and nitrogen-doped graphitized carbon-anchored iron nanoparticles (Fe–N–C) are prepared. Then, Fe–N–C is pyrolyzed with selenium dioxide (SeO2) to convert iron (Fe) nanoparticles into iron selenide (FeSe) in situ to obtain nitrogen-doped graphitized carbon-anchored FeSe nanoparticle catalysts (FeSe/NC). The catalyst's carbon support has excellent electrical conductivity, which effectively promotes the transport rate of charges and enhances the catalytic activity of FeSe particles. FeSe/NC demonstrates outstanding catalytic activity for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). When utilizing FeSe/NC catalysts in rechargeable zinc-air batteries (ZABs-FeSe/NC), the most excellent power density could exceed 186.6 mW cm−2, and the specific capacity can achieve 905.2 mAh g−1, demonstrating excellent performance. Furthermore, the battery can achieve stable charge-discharge for longer than 200 h at a large current density of 10 mA cm−2, which has excellent practical application feasibility in the future.

Development of Fe-Doped Ni2P-POx Electrocatalyst for Oxygen Evolution Reaction

Water electrolysis is extensively researched as a next-generation energy storage method to overcome the intermittency of renewable energy. Electricity generated from renewable sources such as solar and wind power can be converted into pure green hydrogen through water electrolysis. Despite the potential of green hydrogen as a renewable energy storage/carrier medium, the high overpotential resulting from the slow kinetics of oxygen evolution reaction (OER) and the use of expensive noble metals make cost-competitive hydrogen production a significant challenge. Anion exchange membrane water electrolysis (AEMWE) is one method for hydrogen production, offering economic advantages over proton exchange membrane systems as it allows for the use of relatively inexpensive transition metal catalysts like Ni, Fe, and Co due to its alkaline environment.Nickel phosphide (Ni2P)-based catalysts have emerged as highly promising candidates to accelerate the electrocatalytic OER. In particular, the introduction of Fe into Ni2P has been found to induce charge transfer, optimizing the electronic structure and accelerating the OER process. OER catalysts based on transition metal phosphides often exhibit a core-shell structure with phosphide at the core and oxide at the shell during OER measurements. This core-shell structure enhances OER performance through the oxide shell, complementing the deficient electrical conductivity of the phosphide core, resulting in superior catalytic activity and durability. From this perspective, transition metal phosphates are also being studied as electrocatalysts for OER. Phosphates, such as PO3 -, not only promote oxygen adsorbate adsorption but also induce a distorted local metal center geometry that favors OH- adsorption and further oxidation.To address these challenges, this study develops a facile and scalable synthesis of iron-doped nickel phosphide-phosphate (Fe-doped Ni2P-POx) nano-hybrid system as a superior noble-metal free OER powder-catalyst. The utilization of self-filling and pyrolysis approaches facilitates economically viable production of the highly porous phosphide catalyst with a high specific surface area and rough surfaces. X-ray diffractometer, X-ray photoelectron spectroscopy, and electron paramagnetic resonance elucidates the electronic structure modulation, resulting in phosphide-phosphate nano-hybrid structures. Consequently, the catalyst demonstrates excellent OER activity in 1 M KOH, with a significantly low overpotential of 283 mV at 20 mA cm-2, a small Tafel slope of 28.4 mV dec-1, and a superior exchange current density of 8.22 mA cm-2, surpassing state-of-the-art PGM catalysts. Furthermore, its durability over 20 hours indicates its excellent stability, mass transport properties, and mechanical robustness in alkaline media, underscoring its potential as an efficient OER catalyst to facilitate electrocatalytic hydrogen production. Figure 1

Rotating Disk Slurry Electrodeposition of Trimetallic Nickel-Cobalt-Iron Nanoparticles Electrocatalyst on Vulcan Xc-72R for the Oxygen Reduction Reaction in Alkaline Media

Although platinum and platinum group metals (PGMs) catalysts are the most efficient for oxygen reduction reaction, the cost and scarcity of the metals are the reason to look for alternative electrocatalysts. Transition metals, such as cobalt, iron, and nickel, have shown promise as an alternative catalyst to oxygen reduction reactions (ORR). In this work, we electrochemically synthesized nickel-cobalt-iron trimetallic alloy nanoparticles dispersed on carbon Vulcan using Rotating Disk Slurry Electrodeposition (RoDSE). This technique is an energy-efficient green method to synthesize well-dispersed catalysts on carbon and oxide supports for various applications including the oxygen reduction reaction (ORR) for fuel cell applications. Cobalt-nickel iron nanoparticles have been well dispersed in 20 mg carbon Vulcan XC-72R using a negative potential (-1.05V vs Ag/AgCl-sat KCl) in a saturated Argon environment. The electrodeposition potential was obtained from cyclic voltammetry analysis of the metal salts in 0.1m KClO4 solution with an electrochemically cleaned glassy carbon electrode. The starting material precursors were iron chloride, nickel acetate, and cobalt acetate in 0.1 M KClO4 aqueous solution. A 500 micromolar metal salt solution aliquot was added for the electrodeposition every 20 minutes, with a total of 12 aliquots.Compared with commercially available 20% Pt/Vulcan, the synthesized catalyst shows comparable mass activity and durability with an onset potential of 0.78V vs RHE(@0.01mA/cm2), limiting current density of 5.56mA/cm2 and half wave potential of 0.66V vs RHE.The X-ray diffraction (XRD) studies and transmission electron microscopy showed that trimetallic nanoparticles are formed and deposited on the carbon Vulcan support. Moreover, scanning electron microscopy, X-ray fluorescence studies, and transmission emission microscopy show the presence of trimetallic nanoparticles. The RDE and RRDE studies show that the synthesized material is active and may lead to a good and inexpensive catalyst for ORR.

Mechanistic Insights into the Stabilization of In Situ Formed γ-NiOOH Species on Ni60Nb40 Nanoglass for Effective Urea Electro-Oxidation.

The formation of NiOOH on the catalyst surface is widely considered to be the active species in electrochemical urea oxidation reactions (UOR). Though in situ-formed NiOOH species are reported to be more active than the synthesized ones, the mechanistic study of the actual active species remains a daunting task due to the possibility of different phases and instability of surface-formed NiOOH. Herein, mechanistic UOR aspects of electrochemically activated metallic Ni60Nb40 Nanoglass showing stability toward the γ-NiOOH phase are reported, probed via in situ Raman spectroscopy, supported by electron microscopy analysis and X-ray photoelectron spectroscopy in contrast with the β-NiOOH formation favored on Ni foil. Detailed mechanistic study further reveals that γ-NiOOH predominantly follows a direct UOR mechanism while β-NiOOH favors indirect UOR from time-dependent Raman study, and electrochemical impedance spectroscopy (EIS) analysis. The Nanoglass has shown outstanding UOR performance with a low Tafel slope of 16mVdec-1 and stability for prolonged electrolysis (≈38mAcm-2 for 70h) that can be attributed to the nanostructured glassy interfaces facilitating more γ-NiOOH species formation and stabilization on the surface. The present study opens up a new direction for the development of inexpensive Ni-based UOR catalysts and sheds light on the UOR mechanism.

Iron‐Catalyzed Vinylogous Michael Addition of Boron Dipyrromethene (BODIPY) Derivatives to para‐Quinone Methides

AbstractWe report herein an effective method for an iron‐catalyzed vinylogous Michael addition of BODIPY derivatives to para‐quinone methides under mild conditions. The corresponding BODIPY‐derived diarylmethane compounds were obtained in 65–93 % yields. This method is featured by its inexpensive catalyst, simple reaction condition and broad substrate scope.

Contact-Electro-Catalysis Through Electret Behavior to Facilitate Electron Transfer.

Contact-electro-catalysis (CEC) usually uses polymer dielectrics as its catalysts under mechanical stimulation conditions, which although has a decent catalytic dye degradation effect still warrants performance improvement. A carrier separation promotion strategy based on an internal electric field by polarization can effectively improve ferroelectric material performance in photocatalysis and piezocatalysis. Therefore, carrier separation as a necessary process of CEC also can be promoted and is largely expected to improve CEC performance theoretically. However, the carrier separation enhancement by the internal electric field strategy has not been achieved in the CEC experiment yet, because of the difficulty of building an internal electric field in an inert polymer dielectric. Herein, a polytetrafluoroethylene (PTFE) dielectric was charged through an electret process, which was believed to establish an internal electric field for CEC catalysts proved by KPFM, XPS, and triboelectric nanogenerator voltage output analysis. The fastest degradation rate of methyl orange reached over 90% at 1.5 h, while the hydroxyl free radical (•OH) yield of the PTFE electret was nearly three times that of the original PTFE. Density functional theory (DFT) calculations verified that the potential barrier of interatomic electron transfer between PTFE and H2O was reduced by 37% under the internal electric field. The electret strategy used herein to optimize the PTFE catalyst provides a base for the use of other general plastics in CEC and facilitates the production of easily prepared, easily recyclable, and inexpensive polymer dielectric catalysts that can promote large-scale pollutant degradation via CEC.

Preparation of a novel Cu‐Ni mixed nanoparticles immobilized on clay: An Eco-friendly Nanocatalyst for mild synthesis of Benzimidazoles and pyrimidines

In the present work, Cu‐Ni mixed nanoparticles immobilized in magnetic clay (MMT-BAC@Fe3O4@CuNi) nanocatalyst were successfully synthesized using a simple method for the first time. In the design of this catalyst, nickel and copper ions were reduced and deposited on clay layers using a benzalkonium chloride directing group. The proposed method offers a safe, sustainable, and selective approach for the synthesis of 2-substituted benzimidazole and 3,4-dihydropyrimidin-2(1H)-ones using an environmentally friendly nanocatalyst. The solid catalyst was distinguished using a diversity of methods, including EDX (Energy Dispersive X-Ray), XRD (X-ray Diffraction), ICP (Inductively Coupled Plasma), VSM (Vibrating Sample Magnetometer), FT-IR (Fourier Transform Infrared Spectroscopy), TEM (Transmission Electron Microscopy) and FE-SEM (Field Emission Scanning Electron Microscopy). The significant features of this new protocol include good to excellent efficiency, oxidant-free conditions, low catalyst loading, inexpensive and non-toxic catalyst, simple procedure, moderate conditions, straightforward work-up, short reaction times, and easy reuse of the nanocatalyst.

The Simpler the Better: One‐Pot Production of γ‐Valerolactone from Biomass Conversion through All‐In‐One Sc(OTf)3 Catalyzed Cascade Reaction

Abstractγ‐Valerolactone (GVL) derived from non‐edible biomass resources has attracted much intense attention from both academia and industry, due to its excellent properties as green solvent and ideal renewable feedstock for production of bioenergy and biorefinery. However, the practical application of current synthetic technologies is restricted by complicated catalyst system and high production cost so far. Here we report a simple but highly efficient method to realize one‐pot synthesis of bio‐derived GVL by a series of Lewis acidic triflates (M(OTf)3 (M=Sc3+, Ln3+)) under mild condition, achieving up to 78 % GVL yield from furfural (FUR) without any additives or pretreatments. Systematic mechanistic studies, including reaction monitoring, identification of key intermediates and deuterium control experiments disclose the nature of such one‐pot conversion by all‐in‐one Sc(OTf)3. This system exhibits several excellent features such as commercially available and inexpensive catalyst, 100 % carbon atom‐economy, environmentally friend, simple preparation and separation procedures. This method could also be applied to the upstream raw materials, including xylose, hemicellulose and even corncob, achieving GVL in 36 %, 35 % and 21 % yields in one‐pot manner, respectively.

Transition metal catalysts coordinated with electrochemistry for preparation of graphene

It is still crucial to produce mass high-quality graphene through simple and low-cost methods for its wide applications. Herein, a simple and fast method by combining inexpensive transition metal catalysts with electrochemistry to exfoliate natural flake graphite is reported. The electrode is prepared in a sandwich structure, where the titanium mesh will enwrap the nickel net coated with graphite powder. This method can quickly achieve the large-scale preparation of graphene within 15 min. The quality of graphene with large lateral size and few layers has been characterized by XRD, SEM, TEM, Raman, and AFM. The possible electrochemical exfoliation mechanism has been proposed. Oxygen evolution reaction occurs at the anode due to the transition metal catalysts, and hydrogen ions (H+) are generated along with oxygen, H+ and SO42− ions will form a local strong acid. The formation of strong acidic H2SO4 in-situ around electrode will oxidize the edge of the graphite, allowing the intercalation of SO42−, H2O, SO2 and O2 into the graphite sheets, which will inflate the graphite and exfoliate of graphite into graphene. This strategy is reliable, environmentally friendly, and suitable for industrial production.

InCl3-Catalyzed One-Pot Synthesis of Pyrrolo/Indolo- and Benzooxazepino-Fused Quinoxalines.

In this paper, we describe an efficient InCl3-catalyzed two-component reaction of 1-(2-aminophenyl)pyrroles/indoles and 2-propargyloxybenzaldehydes for the direct synthesis of 12bH-benzo[6,7]1,4-oxazepino[4,5-a]pyrrolo/indolo[2,1-c]quinoxalines. This high atom- and step-economical one-pot process generates three new C/N-C bonds in a single synthetic operation, resulting in the formation of new six- and seven-membered heterocyclic rings. The easy availability of the starting materials, the use of the relatively inexpensive indium catalyst, and the good substrate scope are the salient features of this strategy. The proposed mechanistic pathway involves imine formation, two consecutive cyclizations via electrophilic aromatic substitution and nucleophilic addition reactions, and the H shift step.

Multi-metal ferrite as a promising catalyst for oxygen reduction reaction in microbial fuel cell.

Improving catalytic activity of cathode with noble metal-free catalysts can significantly establish microbial fuel cells (MFCs) as a sustainable and economically affordable technology. This investigation aimed to assess the viability of utilizing tri-metal ferrite (Co0.5Cu0.5 Bi0.1Fe1.9O4) as an oxygen reduction reaction (ORR) catalyst to enhance the performance of cathode in MFCs. Trimetallic ferrite was synthesized using a sol-gel auto-combustion process. Electrochemical evaluations were conducted to assess the efficacy of as-synthesized composite as an ORR catalyst, employing electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). This evaluation revealed that the impregnation of bismuth in the Co-Cu-ferrite structure improves the reduction current response and reduces the charge transfer resistance. Further experiments were conducted to test the performance of this catalyst in an MFC. The MFC with tri-metal ferrite catalyst generated a power density of 11.44 W/m3 with 21.4% coulombic efficiency (CE), which was found to be comparable with commercially available 10% Pt/C used as cathode catalyst in MFC (power density of 12.14 W/m3 and CE of 23.1%) and substantially greater than MFC having bare carbon felt cathode without any catalyst (power density of 2.49 W/m3 and CE of 7.39%). This exceptionally inexpensive ORR catalyst has adequate merit to replace commercial costlier platinum-based cathode catalysts for upscaling MFCs.

Unlocking the Potential of Deep Eutectic Solvents and Ligand-to-Metal Charge Transfer Processes: A Reusable Iron-and-UV-Based System for Sustainable C-C Bond Formation.

Catalytic C-H functionalization has provided new opportunities to access novel organic molecules more sustainably and efficiently. However, these procedures typically rely on precious metals or complex organic catalysts as well as on hazardous solvents or reaction conditions. Herein, a pioneering methodology for direct C-C bond formation enabled by Ligand-to-Metal Charge Transfer (LMCT) and mediated by UV irradiation has been developed using Deep Eutectic Solvents (DESs) as sustainable reaction media. This direct C-H bond functionalization via a radical addition to electrophiles was successfully confirmed over a broad scope of substrates. More importantly, this is the first example of photocatalytic C-C bond formation in DESs. An inexpensive and abundant iron catalyst (FeCl3) was used under air and mild conditions. Different functional groups were well tolerated obtaining promising results that were comparable to those reported in the literature. Additionally, the reaction medium along with the catalyst could be reused for up to 5 consecutive cycles without a significant loss in the reaction outcome. Several green metrics were calculated and compared to those of conventional procedures, revealing the advantages of using DESs.

Synergistic rapid removal of U(VI) from radioactive wastewater by photoexcitation-driven Z-scheme heterojunction hydrogel

The development of inexpensive and efficient semiconductor catalysts for uranium removal from wastewater via photoreduction remains challenging. Herein, we successfully synthesized Z-scheme heterojunction LaOCl-ZnO-1.5 photocatalyst by ultrasound-assisted in-situ deposition technology followed by immobilization in sodium alginate (SLZ-1.5) by an embedding strategy for the reductive removal of U(VI) from uranium-containing wastewater. The construction of a heterojunction achieves synergistic effects, improving optical response range and photocatalytic efficiency, reducing the loss of photocatalyst through immobilization in the gel structure, and simultaneously solving the difficulty of recycling powder catalysts. SLZ-1.5 demonstrated superior photocatalytic properties for the reduction of U(VI) and rapid reaction kinetics (120 min, 96.1 %) under visible-light irradiation by a xenon lamp. Through the synergistic effect of adsorption and photocatalysis, its optimal removal capacity for U(VI) reached 520.8 mg/g. SLZ-1.5 exhibited great recyclability and excellent selectivity (1.22 × 104 mL/g). In addition, the outstanding performance (98.6 %) of SLZ-1.5 in a dynamic adsorption column under visible-light irradiation validated its potential for practical applications. The photoreduction mechanism indicated that the excellent photocatalytic performance of LaOCl-ZnO-1.5 was enabled by its great light absorption capacity and appropriate bandgap. SLZ-1.5 heterojunction hydrogel is a successful example of a promising adsorption-reduction coupling material that can be applied for the purification and treatment of uranium-containing wastewater.

Regulate the adsorption of oxygen-containing intermediates to promote the reduction of CO2 to CH4 on Ni-based catalysts

The introduction of oxophilic metals can enhance the selectivity of CO2 reduction reactions (CO2RR) by modulating the adsorption of oxygen-associated active substances on the catalyst surface. Alloying lanthanide atoms into metals has been shown to improve CH4 selectivity by breaking the linear relationship between the adsorption energies of CO* and HxCO*. In this work, a series of oxophilic transition metals (Fe, Mo, Co, Mn) are introduced to explore the influence on the CO2RR. DFT results demonstrate that the doping of oxophilic metals regulates the adsorption strength between the catalyst surface and intermediates, thereby affecting the CH4 and H3COH pathways. Notably, COOH* formation is enhanced on Ni surfaces, leading to increased H3COH production. Ni-Fe and Ni-Mo exhibit significant H3CO* and CO2* binding energies, which reduces the barrier for H3CO*. Meanwhile, the bond energy of M−O is higher than that of C-O in H3CO*, promoting the generation of CH4. The addition of Co and Mn makes the desorbed of HCOOH smaller than the hydrogenation energy barrier, which accelerates the synthesis of formic acid. This research provides a new pathway for the development of inexpensive and resource-rich catalysts.

Nickel metal particles encapsulated in carbon shells as efficient bifunctional electrocatalysts for urea-assisted hydrogen production

Urea oxidation reaction (UOR) is considered an ideal water splitting reaction with the potential to replace oxygen evolution reaction (OER), as it lowers the anodic potential and utilizes urea as a renewable and abundant resource. However, creating stable, effective bifunctional catalysts is still challenging. In this work, we report a novel bifunctional catalyst of core-shell structure Ni-500 Nano-particle. The carbon coating not only offers numerous active sites and facilitates rapid charge transfer but also shields the nickel core from corrosion. Moreover, By replenishing the urea concentration, the current density can be recovered and sustained for 50 h with only an 8 % decrease. It is significantly less than pure water electrolysis that the urea-assisted water electrolyzer with Ni-500 as both cathode and anode achieves cell-voltage of 1.55 V at 100 mA cm−2. This work demonstrates the potential of Ni-500 as a inexpensive and effective catalyst for urea-based hydrogen production, and offers new perspectives into the design and optimization for core-shell structure electrocatalyst.

Copper-Vit B3 MOF preparation, characterization and catalytic evaluation in a one-pot synthesis of benzoxanthenones with docking validation as anti H. pylori.

Copper-Vit B3 MOF was successfully prepared by efficient and eco hydrothermal method. The prepared MOF was characterized as a tetragonal crystal copper-MOF nanoparticles by FTIR, SEM, TEM, EDX and XRD. The prepared nanoparticles were used as an effective, inexpensive and low-toxic catalyst in the one-pot synthesis of some new benzoxanthenone derivatives. As example 4-(9,9-dimethyl-11-oxo-8,10,11,12-tetrahydro-9H-benzo[a]xanthen-12-yl)phenyl benzoate (4h) was synthesized in high yield 92%. The MOF catalyst's role is activating the nucleophilic attack by increasing the carbonyl polarization, and this generally improves the reaction time, which ranges between 20-60 minutes and products' yields ranging between 80-92%. Prepared compounds (4a-4j) undergo molecular docking scanning as Helicobacter pylori type II dehydroquinase inhibitors, and the data obtained showed that there are three promises of the prepared compounds 4d, 4e, 4h and 4j compared with amoxicillin.

Supercritical water upgrading of heavy oil: Effects of reservoir minerals on pyrolysis product distribution

Supercritical water upgrading (SCWU) is a promising technology for heavy oil recovery and refining, in which minerals could act as catalysts, but the effect on the upgraded product distribution remains unclear. In this study, heavy oil upgrading experiments in supercritical water (SCW) were carried out at 400°C and 25 MPa to investigate the effects of reservoir minerals such as quartz, carbonate, feldspar and clay minerals on the upgrading process. The result indicated that carbonate minerals and clay-bearing minerals produced noticeable benefits to the SCWU of heavy oil process. In carbonate minerals, dolomite showed the strongest catalytic effect in promoting hydrothermal cracking of hydrocarbon macromolecules, with a 5.6 % reduction in heavy fraction and a 12.2 % increase in light fraction of the upgraded oil. Clay-bearing minerals mainly exhibited oil-enhancing and coking-inhibiting benefits, calcium montmorillonite exhibited the most significant increase in oil production of 9 %, while zeolite most significantly reduced the coke activation energy by 62 %. Regarding the catalytic mechanism, the catalytic effect of carbonates originated from the MgO and CaO sites on the surface. For clay minerals, the acidic catalytic sites exist in the interlayer domains of montmorillonite and in the pores of zeolite provided higher catalytic efficiencies in oil production. This study demonstrated the feasibility of using natural minerals as inexpensive catalysts for supercritical water upgrading of heavy oil.

Promoted production of aromatic hydrocarbons in biomass catalytic pyrolysis over the coupled catalysts of carbon-reduced waste lithium battery cathode materials and HZSM-5

Inexpensive catalyst sources are of great importance in the conversion of biomass to economically valuable monocyclic aromatic hydrocarbons, and transition metals (Co, Ni, Fe and Mn) rich in catalytic effects in massive waste lithium battery cathode materials are not effectively reutilized currently. For this reason, the feasibility of employing the valuable metal oxides in the carbon-reduced waste lithium battery cathode materials (waste LiFePO4 batteries, LFP, and waste LiNixCoyMn1–x–yO2 batteries, NCM) with HZSM-5 as coupled catalysts in the rape straw catalytic pyrolysis to produce aromatic hydrocarbons was explored. The carbon-reduced waste lithium battery cathode materials performed well at 5 wt% carbon loading, and the content of active components Fe2O3 (SLFPC-5) and NiO (SNCMC-5) used for the reduction of large molecular oxygenates in biomass pyrolysis gas was increased by water leaching treatment. SLFPC-5 demonstrated superior bond-cutting performance, while SNCMC-5 exhibited strong deoxygenation performance. The selectivity of monocyclic aromatic hydrocarbons (MAHs) catalyzed by SLFPC-5/HZSM-5 and SNCMC-5/HZSM-5 was as high as 63.69 % and 79.19 %, with BTX yields of 14.58 wt% and 16.68 wt% respectively. This coupled catalytic system offers a low-cost source of catalysts for biomass catalytic pyrolysis and broadens the possibility of high-value recycling of wasted lithium batteries.

Controlled synthesis of M doped NiMoO4 (M = Co, Cu and Fe) for urea, freshwater and seawater oxidation reaction

Electrocatalytic splitting of urea or seawater for hydrogen production has become one of the most promising methods. In this paper, different foreign ions M (M = Co, Cu and Fe) are introduced into this NiMoO4 material by hydrothermal and impregnation methods. Their electrocatalytic properties were investigated in different electrolytes, such as urea, pure water and seawater. What is noteworthy is that the Co-NiMoO4/NF electrode exhibited superior urea oxidation properties (1.32 V @ 10 mA cm−2). The different reaction mechanisms result in the superior water oxidation performance of this Fe3+-NiMoO4/NF material. What is noteworthy is that the durability of the material needs to be improved. The promoted performance is attributed to rapid electron transfer and improved electrical conductivity. Density functional theory (DFT) also shows that this Fe-NiMoO4/NF electrode presents optimal water adsorption energy and improved electrical conductivity, thus improving the catalytic activity of the material because of introduction of Fe. The work provides novel views for the design of environmentally friendly and inexpensive multifunctional catalysts for urea, freshwater and seawater splitting reaction.