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Efficient and low-cost nanocatalysts are extremely desirable for the catalytic reduction of 4-nitrophenol (4-NP). A smaller nanocatalyst particle size and stronger support effect can significantly enhance the catalytic performance. Naturally occurring halloysite nanotubes (HNTs) are promising alternative supports for fine metal nanoparticles, but the smooth surface and single type of functional groups on HNTs are usually unfavorable for the anchoring of metal ions. Herein, we modified HNTs using a mild and controllable molten salt etching method to create a rough surface (rHNTs), followed by loading Pt–Ni alloys to prepare Pt–Ni/rHNTs for the catalytic reduction of 4-NP. The results demonstrate that ultrafine Pt–Ni alloy nanoparticles with a diameter of 1.60 nm are uniformly dispersed on the rough surface of rHNTs. The particle size and catalytic performance can be tuned by adjusting the loading amount of Pt–Ni. The optimized Pt–Ni/rHNT (1 wt %) nanocatalyst reveals the smallest Pt–Ni particle size and the highest catalytic rate of 0.1953 min−1, which exceeds many Pt–Ni-based catalysts in previous reports. This work offers an ingenious idea for the mild surface modification of HNTs and a brilliant perspective for the rational design of inexpensive 4-NP reduction nanocatalysts. [ABSTRACT FROM AUTHOR]

Surface area, pore properties, synergistic behavior, homogenous dispersion, and interactions between carbon matrix and metal‐nanostructures are the key factors for achieving the better performance of carbon‐metal based (electro)catalysts. However, the traditional hydro‐ or solvothermal preparation of (electro)catalysts, particularly, bi‐ or tri‐metallic nanostructures anchored graphene (G) or carbon nanotubes (CNTs), often pose to poor metal–support interaction, low synergism, and patchy dispersion. At first, bimetallic flower‐like‐CuFeS2/NG and cube‐like‐NiFeS2/NCNTs nanocomposites were prepared by solvothermal method. The resultant bimetallic nanocomposites were employed to derive the 2D‐nano‐sandwiched Fe2CuNiS4/NGCNTs‐SW (electro)catalyst by a very simple and green urea‐mediated "mix‐heat" method. The desired physicochemical properties of Fe2CuNiS4/NGCNTs‐SW such as multiple active sites, strong metal‐support interaction, homogenous dispersion and enhanced surface area were confirmed by various microscopic and spectroscopic techniques. To the best of our knowledge, this is the first urea‐mediated "mix‐heat" method for preparing 2D‐nano‐sandwiched carbon‐metal‐based (electro)catalysts. The Fe2CuNiS4/NGCNTs‐SW was found to be highly effective for alkaline‐mediated oxygen evolution reaction at low onset potential of 284.24 mV, and the stable current density of 10 mA cm−2 in 1.0 m KOH for 10 h. Further, the Fe2CuNiS4/NGCNTs‐SW demonstrated excellent catalytic activity in the reduction of 4‐nitrophenol with good kapp value of 87.71 × 10−2 s−1 and excellent reusability over five cycles. Overall, the developed urea‐mediated "mix‐heat" method is highly efficient for the preparation of metal‐nanoarchitectures anchored 2D‐nano‐sandwiched (electro)catalysts with high synergism, uniform dispersion and excellent metal‐support interaction. [ABSTRACT FROM AUTHOR]

Catalytic conversion of water pollutants into environmentally benign products has emerged as a highly promising technique in the realm of environmental remediation. Among metal and metal oxide nanoparticles, copper/copper oxide nanoparticles serve as an ideal catalyst to reduce hazardous aquatic pollutants in order to protect the environment. In the present study, a simple chemical oxidation method was used for the synthesis of Cu(OH)2 nanowire, which was then annealed in argon atmosphere at different temperatures. On annealing, Cu(OH)2 gets transformed into oxide forms, CuO and/or Cu2O. The significance of the synthesized nanomaterial for the catalytic conversion of organic pollutants like para-nitrophenol (p-NP) and para-nitroaniline (p-NA), to para-aminophenol (p-AP) and para-phenylenediamine (p-PDA), respectively, in the presence of NaBH4 was studied and their catalytic activities were compared, and the rate constants were found to be 0.016 s−1 and 0.021 s−1 for p-NP and p-NA respectively. Due to the increased surface area, which improves charge carrier separation and adsorption, the CuO/Cu2O hybrid nanowires established excellent catalytic behavior for the conversion of these harmful pollutants into useful products within a few minutes. In addition to this, the heterojunction of CuO/Cu2O hybrid nanowires formed are effectively catalyze the "clock reaction," which is a periodic reversible switching of reactions between colorless leucomethylene blue and blue colored methylene blue. This property of the developed nanocomposite has been used in the visual colorimetric detection of Zn2+ions, with high limit of detection of 53 nM and high sensitivity. Morphology and surface analysis were obtained by X ray diffraction, Raman, and Scanning Electron Microscopic analysis and the reaction kinetics were studied by UV–visible spectroscopy. The recyclability of the synthesized catalyst was investigated over five cycles, and it maintained consistent performance, achieving 95% conversion efficiency for p-NP and 93% for p-NA after the five cycles. [ABSTRACT FROM AUTHOR]

Selective catalytic reduction (SCR) flue gas denitrification systems are inherently complex, typically embodying characteristics of non-linearity, significant time delays, and susceptibility to multiple disturbances. In the context of coal power units engaging in deep load cycling and rapid frequency adjustment, conventional proportional-integral-derivative (PID) control struggles to meet the demands of effective control. This study introduces a control strategy that incorporates a "state observer + Linear Quadratic Regulator (LQR) state feedback + Improved Quantum Genetic Algorithm (IQGA) optimized PID". Initially, local linear mathematical models of an SCR denitrification system at 340 MW, 450 MW, and 540 MW loads were used to design state observer and LQR state feedback control parameters for each operational condition. At a single load point, the IQGA was employed to optimize the outer loop PID parameters, followed by simulation experiments of load increases and decreases between 340 MW and 540 MW. The results demonstrated that, compared to two other strategies, the proposed approach reduced the overshoot by a minimum of 1.5% and shortened the adjustment time by 31.7% under conditions of step disturbances and internal perturbations. Throughout variable operational conditions, the strategy consistently exhibited minimal output fluctuations, rapid adjustment capabilities, strong disturbance rejection, and robust stability. This algorithm proves to be an effective method for controlling NOx concentrations, offering insights for precise ammonia injection control in future applications. [ABSTRACT FROM AUTHOR]

The effects of reaction temperature, reaction time, heating rate, nitrogen flow rate, and catalyst quality on the oil yield and oxygen content in oil were investigated by using the single-factor principle. Too high and too low reaction temperature, nitrogen flow rate, heating rate, and reaction time improved the yield of bio-oil, but the oxygen content in bio-oil was higher. The reduction in catalytic dose is beneficial to the increase in oil yield but not conducive to the increase in aromatic compound content. The optimal reaction conditions were observed as a reaction temperature of 500 °C, a nitrogen flow rate of 110 mL/min, a heating rate of 20 °C/min, a reaction time of 15 min, a mass ratio of catalyst to coconut coat powder of 1, an oil yield of 4.97%, a water yield of 35.80%, and a solid yield of 30.78%. The gas yield was 28.45%, the oxygen content was 10.3%, and the aromatic compound content was 89.7%. The analysis of the catalytic cracking mechanism shows that most of the oxygen-containing compounds in bio-oil are generated into water and aromatic compounds by a catalytic cracking reaction at high temperature, thus removing oxygen. [ABSTRACT FROM AUTHOR]

The proper selection of a relevant mixer generally requires an effective assessment of several models against the application requirements. This is a complex task, as traditional evaluation methods generally focus only on a single aspect of performance, such as pressure loss, mixing characteristics, or heat transfer. This study assesses a urea-based selective catalytic reduction (SCR) system installed on a ship, where the installation space is limited and the distance between the urea aqueous solution injection position and the reactor is low; therefore, the static mixer installed in this pipeline has special performance requirements. In particular, four evaluation indices are used in this study: The B value, C value, pressure loss correction factor (Z′), and the ratio of the required distance to the equivalent diameter of the pipe (LV/D) when the velocity field after the mixer attains uniformity. Six types of static mixers were simulated with varying concentrations, flow speeds, and positions. A fuzzy comprehensive evaluation method was introduced to evaluate and compare the related advantages and disadvantages. The results showed that 1) mixing performance was related to the shape of the mixer and had no direct relationship with flow velocity. 2) For the same mixer position, the lower the urea concentration, the greater the difficulty of evenly mixing the solution. 3) At a constant urea concentration, the mixing performance improved when the mixer was closer to the injection inlet. 4) The installation of a GK mixer in the SCR system of a 9L20C diesel engine was best. [ABSTRACT FROM AUTHOR]

Developing an efficient catalyst is the key to selective catalytic reduction (SCR) of NOx by CO (CO‐SCR) to simultaneously address the pollution of toxic NOx and CO. Herein, a novel Rh/TiO2/Ti monolithic catalyst is designed and synthesized, featuring Rh species in the form of single atoms (Rh1) and clusters (Rhn). This catalyst overcomes the inhibitory effects of oxygen, achieving low‐temperature NO conversion. The investigation substantively contributes insights into the strategic manipulation of active metal components, emphasizing the potential of single‐atom/cluster catalysts to enhance efficiency. The Rh/TiO2/Ti catalyst has demonstrated exceptional catalytic efficacy, achieving 100% NO conversion at a low temperature of 190 °C in the presence of oxygen. Additionally, it exhibits remarkable stability and water resistance for practical applications. Moreover, comprehensive characterization confirms that Rh clusters and single‐atom sites play an important role in the selective adsorption of NO and CO molecules, promoting the formation of –N2O species and ultimately resulting in the complete conversion of NO and CO to N2 and CO2. This study not only provides valuable guidance for designing high‐performance CO‐SCR catalysts but also underscores the potential of single atoms/clusters catalytic systems in both fundamental research and industrial catalysis. [ABSTRACT FROM AUTHOR]

Activated carbon can be used as a catalyst for the reduction of Co(III)TETA to Co(II)TETA so as to maintain the ability of removing NO from gas stream with Co(II)TETA solution. Calcium nitrate has been utilized to treat activated carbon to improve its catalytic ability in the regeneration of Co(II)TETA. The biggest Co(III)TETA conversion is gained by the carbon being soaked in 0.3 mol/L calcium nitrate solution at 65°C for 12 h with a solid/liquid ratio of 1 g/50 mL followed being carbonized at 400°C for 2 h in nitrogen. The characterization with Fourier transform infrared spectroscopy, XPS, BET (Brunauer‐Emmett‐Teller) and Boehm titration indicates that the modification with calcium nitrate increases the specific surface area and acidic groups on activated carbon. The continuous experiments reveal that the NO removal efficiency obtained by the modified carbon is over 12% up to that by the original one. [ABSTRACT FROM AUTHOR]

The cube‐like copper ferrite (CuFe2O4) nanocrystallines are produced by the hydrothermal method without using any surfactant. X‐ray diffraction (XRD), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT‐IR) are used to characterize the morphology, structure, and phase of the samples. CuFe2O4 nanocubes show the superior catalytic performance of reduction 4‐nitrophenol (4‐NP) to 4‐aminophenol (4‐AP). 20 mg CuFe2O4 nanocubes can totally convert 4‐NP to 4‐AP in 30 s at room temperature. Moreover, the reaction kinetics of 4‐NP catalytic reduction are also studied. Hence, this innovative CuFe2O4 nanocube has a lot of potential for organic pollutant destruction. [ABSTRACT FROM AUTHOR]

Furfural is an attractive bio‐based platform chemical that has many derivatives of commercial interest. Herein, we show that the selectivity of the direct furfural reduction can be steered from 2‐methylfuran and 2‐methyltetrahydrofuran to furfuryl alcohol and tetrahydrofurfuryl alcohol by varying the ratio of formic acid and sodium formate. These reagents take the role of terminal reductants in the disclosed heterogeneous Pd‐catalysed process. We report the development and optimisation of the reaction conditions for three different products directly from furfural: 2‐methyltetrahydrofuran, tetrahydrofurfuryl alcohol and 2‐methylfuran which were obtained in 59 %, 46 %, and 63 % selectivity, respectively. Furthermore, the protocol uses commercially available Pd/Al2O3 as catalyst and the formic acid and sodium formate can be obtained from biogenous sources. [ABSTRACT FROM AUTHOR]

The accurate and rapid detection of persulfate concentration is important for environmental decontamination and human health protection. In this work, a novel self-powered electrochemical sensor for the sensitive monitoring of persulfate was developed, which utilized cobalt tetroxide (Co3O4@CC) or tin-doped cobalt tetroxide (SnxCo3−xO4@CC) cathode as the sensing element and anode with electrogenic microorganisms as the power supplier. The Co3O4@CC and SnxCo3−xO4@CC electrodes were fabricated by in situ growing nanostructured Co3O4 or SnxCo3−xO4 catalysts on carbon cloth. Electrochemical tests revealed that these electrodes exhibited excellent catalytic reduction performance toward persulfate because of the synergistic catalysis by Co3O4 and electrode electrons, well-exposed Co2+/Co3+ catalytic sites, and high electron transfer efficiency. Tin doping could enhance the catalytic persulfate reduction by improving the conductivity and electron transfer of the Co3O4 catalyst. The electrode prepared at a hydrothermal temperature of 90 °C and a tin dosage of 0.286 g·cm−2 achieved the highest persulfate reduction activity under pH 7. The sensing properties of the self-powered sensors toward persulfate were explored in detail. Results showed that under the optimal external load of 300 Ω, the proposed sensor could display a broad detection range of 0 to 1500 μmol L−1 K2S2O8 with sensitivities of 1.13 and 0.12 μA μmol−1 L, a detection limit of 1.11 μmol L−1 (S/N = 3), and a fast response time within 30 s. The sensors also presented satisfactory reproducibility and selectivity during the detection of persulfate. The proposed sensor will provide a new approach for sensitive, on-site, and real-time monitoring of persulfate for a wide range of applications. [ABSTRACT FROM AUTHOR]

[Display omitted] The rational construction of highly active and robust non-precious metal oxygen reduction electrocatalysts is a vital factor to facilitate commercial applications of Zn-air batteries. In this study, a precise and stable heterostructure, comprised of a coupling of Co 3 Fe 7 and Fe 3 C, was constructed through an interface engineering-induced strategy. The coordination polymerization of the resin with the bimetallic components was meticulously regulated to control the interfacial characteristics of the heterostructure. The synergistic interfacial effects of the heterostructure successfully facilitated electron coupling and rapid charge transfer. Consequently, the optimized CST-FeCo displayed superb oxygen reduction catalytic activity with a positive half-wave potential of 0.855 V vs. RHE. Furthermore, the CST-FeCo air electrode of the liquid zinc-air battery revealed a large specific capacity of 805.6 mAh g Zn -1, corresponding to a remarkable peak power density of 162.7 mW cm−2, and a long charge/discharge cycle stability of 220 h, surpassing that of the commercial Pt/C catalyst. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Traditional reduction coupling reactions of two bromides typically rely on transition metal catalysis. Here, we introduce the development of a visible‐light catalytic direct reduction coupling reaction between α‐CF3‐alkyl bromides and alkynyl bromides to access valuable organic frameworks. Our research confirms the excellent compatibility of this reaction with various functional groups, which could be used to modify the substrate with biologically active molecular fragments. Mechanistic investigations, including control experiments, fluorescence quenching studies, and light‐switching experiments, have provided insights into the reaction mechanism. This study paves the way for the application of visible‐light catalysis in diverse synthetic transformations, offering a sustainable and efficient approach to organic synthesis. [ABSTRACT FROM AUTHOR]

Selective catalytic reduction of nitrogen oxides with NH3 at low temperatures remains a crucial goal for industrial applications. However, effective catalysts operating at 70–90 °C are rarely reported, limiting SCR scenarios to high‐temperature conditions. Herein, we report a unique MnO2 nanofilament catalyst grown on activated semi‐coke synthesized via a one‐step in situ hydrothermal approach, which exhibits a stable and marked 100 % conversion rate of NO to N2 with 100 % selectivity at 90 °C, superior to the other prepared structures (nanowires, nanorods, and nanotubes). Temperature‐programmed desorption shows a large number of acid sites on MnO2(NFs)/ASC, benefiting the formation of NH4+ ions. Meanwhile, diffuse reflectance infrared Fourier transform spectroscopy reveals the activation of NO with O2 to form bidentate nitrate/bridging nitrate NO2 intermediates via bidentate nitrate species, triggering the Fast SCR with NH3 at low temperatures. Such an effective, easy‐to‐prepare, and low‐cost catalyst paves a new pathway for low‐temperature SCR for a wide range of application scenarios. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Traditional reduction coupling reactions of two bromides typically rely on transition metal catalysis. Here, we introduce the development of a visible‐light catalytic direct reduction coupling reaction between α‐CF3‐alkyl bromides and alkynyl bromides to access valuable organic frameworks. Our research confirms the excellent compatibility of this reaction with various functional groups, which could be used to modify the substrate with biologically active molecular fragments. Mechanistic investigations, including control experiments, fluorescence quenching studies, and light‐switching experiments, have provided insights into the reaction mechanism. This study paves the way for the application of visible‐light catalysis in diverse synthetic transformations, offering a sustainable and efficient approach to organic synthesis. [ABSTRACT FROM AUTHOR]

Nitrogen oxides (NOx) are produced during the high‐temperature combustion process of fossil fuels, which are considered as an atmospheric pollutant that can lead to significant environmental issues such as acid rain and photochemical smog. Therefore, it is essential to minimize the concentration of NOx in the atmosphere in order to protect the ecological environment upon which human beings depends. The integrated utilization of NOx removal technology results in environmentally harmless compounds, such as N2 and H2O, through the processes like adsorption, separation, catalytic reduction and other methods. Metal‐organic frameworks (MOFs) are seen as ideal candidates for addressing NOx pollution issues in the atmosphere due to their high specific surface area, ultrahigh porosity and unlimited modifiability. Herein, the latest research progress in MOFs and MOFs‐derived materials related to NOx adsorption, separation and catalytic reduction is presented and summarized. Besides, some opportunities and problems need to be solved in this field are proposed and discussed. [ABSTRACT FROM AUTHOR]

The chemical absorption biological reduction process gained profound attention in NOx removal. Treatments for NOx are done popularly using NH3 in selective catalytic reduction (SCR), and deNOx is greatly influenced by catalyst. In recent years, zeolites have been widely explored in ammonia‐selective catalytic reduction (NH3‐SCR) under low‐temperature windows. Different methods were employed to juxtapose the performances of zeolite catalysts with denitrification and NH3‐SCR. In this NH3‐SCR reaction, the zeolite catalyst's sulfur and water poisoning effects were also investigated. The negatives of the low‐temperature NH3‐SCR reactions were demonstrated by using different methods. Ideally, this audit will set upon essential comprehension of the SCR response on zeolite catalysts and clear the way for future exploration to accomplish reasonable applications. The current review provides a new strategy to enhance the removal of NOx and reveals the fundamental effects of different types of sustainable catalysts for the environment. Further, the perspective of the economic aspects of each catalyst is also examined. [ABSTRACT FROM AUTHOR]

For the development of Bi/Bi2O3@Al2O3 nanocomposites for wastewater treatment, corrosion resistance, and self-cleaning properties, it is imperative to carefully combine and analyze various elements for the optimization of catalyst performance. We aim to provide effective and long-term environmental remediation solutions. FTIR spectroscopy, XRD, SEM, EDS, TEM, UV-vis spectroscopy, PL, and TGA techniques were used to characterize the Bi/Bi2O3@Al2O3 nanocomposite. The nanocomposite displayed significant supercapacitance and self-cleaning properties. A composite of bismuth–aluminum oxides was used as a catalyst to facilitate the catalytic reduction of 4-nitrophenol (4-NP) dye in aqueous solutions, and excellent catalytic reduction results were obtained. The photocatalyst catalyzed the reduction of 4-NP to 99% with a rate constant of 2.592 × 10−2 (10−2 min−1) in a short period of 40 minutes under UV-visible irradiation. Photogenerated electrons migrate from Bi/Bi2O3@Al2O3 when exposed to visible light as a result of the significant band gap in the conduction band and the structure of the core electrostatic field within the p–n heterojunction. When exposed to visible light, the Bi/Bi2O3@Al2O3 nanocomposite exhibited more charge separation with excellent catalytic reduction efficiency. It represents an important development since it offers effective wastewater treatment remedies, energy storage, and self-cleaning properties. [ABSTRACT FROM AUTHOR]

We employ UV/Vis Diffuse Reflectance spectroscopy directly coupled with a packed bed flow reactor to extract quantitative kinetic information. We use as a show‐case the CuII/CuI redox dynamics during the reduction half cycle of the NH3‐Selective Catalytic Reduction (SCR) on Cu‐CHA catalysts. Our measurements enable quantification of the fraction of oxidized Cu, reconstructed by Multivariate Curve Resolution (MCR) together with monitoring of the gas‐phase evolution during the reaction. These data both on the dynamics of the gas‐phase and of the active site oxidation state have been used to assess the reduction half cycle rate equation and estimate the rate constant. Our results in terms of reaction orders and kinetic constant are in line with previous findings in the literature. Overall, our results demonstrate that the combined analysis of the UV spectra and of the gas‐phase dynamics provides converging and unparalleled kinetic insight: this approach effectively resolves ambiguities concerning RHC kinetics and mechanism. More in general, this work provides evidence that operando spectroscopy can be used to extract quantitative kinetic information on catalytic cycles. [ABSTRACT FROM AUTHOR]

The document is a contents list for the journal CrystEngComm, which focuses on the design and understanding of solid-state and crystalline materials. It includes a cover image and features several communications and papers on various topics such as supramolecular self-assembly, electrocatalysts for water splitting, and temperature sensing applications. The journal is published by The Royal Society of Chemistry, a leading chemistry community that reinvests its profits back into the chemistry community. [Extracted from the article]

The electrochemical proton reactivity of transition metal complexes receives significant attentions. A thorough understanding of proton-coupled electron transfer (PCET) pathways is essential for elucidating the mechanism behind a proton reduction reaction, and controlling the pathway is a key focus in the field of the catalyst development. Spin interactions within complexes, which arise during electron transfer, can affect significantly the PCET pathway. Herein, we explore the phenomenon of spin rearrangement during the electrochemical reorganization of high-spin cobalt complexes. Our findings reveal that opposing spin interactions, induced by different coordination environments, can alter the PCET pathway. Finally, detailed analysis of the PCET pathway allows us to propose mechanisms for proton reduction in high-spin cobalt complexes. Proton-coupled electron transfer (PCET) is an essential process of catalytic proton reduction and can be tuned by altering external or internal factors. Here, the authors control the exchange coupling types of Co complexes as model systems and demonstrate selective control of the PCET process. [ABSTRACT FROM AUTHOR]

Microporous zeolite is commonly employed as the catalyst for selective catalytic reduction of NOx using NH3 as reducing agent (NH3‐SCR) because of its strong acidity and exceptional hydrothermal stability. However, the channel of microporous zeolite limits mass transfer under low temperature. Hierarchical porous molecular sieves can overcome the above imperfections. Hierarchical pore (microporous/mesoporous/macroporous) ZSM‐5 molecular sieves were prepared using polystyrene(PS) microspheres with different particle size as the hard templates and then the ion exchange method was utilized to introduce the active components Ce, Cu, and La. In addition, the effect of PS microspheres with different size and H2O+SO2 on denitrification performance was also investigated. The results exhibited that the specific surface area of the hierarchical pore ZSM‐5 was the smallest when the size of polystyrene microspheres was the largest. The NOx conversion of all supported hierarchical porous catalysts is more than that of supported microporous ZSM‐5 catalyst in the low temperature (200 °C), which was because that the presence of the mesopores favored diffusion‐control in the low temperature, expediting the reactant transport. Furthermore, the supported hierarchical pore ZSM‐5 catalyst exhibited excellent denitrification performance in a wide temperature range of 250–500 °C (the conversion of NOx exceeded 80 % and the N2 selectivity was approaching 100 %). More importantly, the supported hierarchical pore ZSM‐5 catalyst demonstrated notably superior water and SO2 resistance in comparison to the supported micropore ZSM‐5 catalyst. [ABSTRACT FROM AUTHOR]

In this work, small-sized CaO–PdNps nanocomposites were synthesized using Lawsonia inermis leaf extract as a reducing and capping agent. X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) were used to analyze the produced nanocomposites. Based on these investigations, the average particle size was found to be 8±12nm, with a predominantly spherical morphology. The resulting nanocomposite was then tested for catalytic activity in methylene blue reduction. The mass of the catalyst and dye, the concentration of sodium borohydride ([NaBH4]), and the reaction time were all optimized using a central composite design (CCD). A significant correlation between predicted and experimental degradation percentages was shown by the CCD model (R2=0.9901), which also proved statistically significant (p-value=0.0016). Furthermore, a deep learning neural network (DLNN) was used to improve the prediction accuracy over and beyond CCD. There was a good connection between the two models as a result of using the CCD output as DLNN validation data. Mean absolute error (MAE), mean squared error (MSE), root mean squared error (RMSE), mean absolute percentage error (MAPE), and R2 were used to assess the performance of the DLNN. The results (MAE=0.001, MSE=0.01, RMSE=0.001, MAPE=0.001, R2=0.999) validated that all four metrics were successful in forecasting the percentage of degradation. [ABSTRACT FROM AUTHOR]

Background: All light-duty (LD) and heavy-duty (HD) vehicles circulating in the European Union undergo regular checks during mandatory periodic technical inspections (PTI). These inspections promote road safety and environmental protection. Vehicles with defective deNOx aftertreatment systems can result in high emissions of NOx, which is an important air pollutant. The ongoing revision of the "so-called" Roadworthiness Package by the European Commission propose including a new method for measuring NOx from vehicles' exhaust during PTI (NOx-PTI). Results: The results obtained showed an increase in NOx emissions, 8 to 28 times, when the selective catalytic reduction (SCR) unit was not working. The applicability of the NOx-PTI idling test procedure to Euro VI HD vehicles was also investigated satisfactorily. Furthermore, methods to warm-up the vehicle's aftertreatment prior to the NOx-PTI idling test, including standing still free accelerations and urban speed drives, as well as systems conditions before the test, were studied. Five different NOx analysers were assessed against reference equipment to ensure the accuracy of NOx measurements to assess their suitability for PTI purposes. The findings indicate that an urban speed drive is suitable for warming up both LD and HD vehicles. The tested analysers appeared to be suitable for use in PTI. Conclusions: The high NOx emissions recorded when the SCR unit was not working, and their potential environmental impact, highlight the importance of a PTI test capable of detecting malfunctioning vehicles. The study demonstrated that the idle test procedure, testing conditions, and NOx analysers used were effective in performing a NOx-PTI check on both light- and heavy-duty Diesel vehicles, successfully discriminating between functioning and malfunctioning SCR systems. [ABSTRACT FROM AUTHOR]

Transition metal-based mixed metal oxides (MMOs) are nexus nanomaterials that garner significant interest from scientists because of their unique magnetic, electronic, optical and catalytic properties that can easily be tailored by varying their composition and structure. Although MMOs hold significant potential in multifunctional applications, but they are plagued by certain challenges such as identifying the appropriate method for synthesis, complications in controlling the surface area and the oxidation states of the constituent transition metals, while also ensuring the homogenous distribution of the constituent metal ions. Therefore, the present work aims to study the formation of homogenous and porous zinc-copper-nickel mixed metal oxide (ZnCuNi-MMO) by performing calcination of ZnCuNi-LDH at 350 °C. The obtained ZnCuNi-MMO was characterized using PXRD, SEM–EDX and BET techniques. Thereafter, ZnCuNi-MMO was applied as a heterogeneous catalyst for the hydrogenation of p-nitroaniline (p-NA) and catalytic reduction of methyl orange (MO) dye. The pollutant degradation characteristics were assessed using time-dependent UV–Visible absorption spectroscopy showing advanced efficient behavior of ZnCuNi-MMO towards the hydrogenation of p-NA (96.98%) and reduction of MO (95.58%). The catalyst exhibited fast reaction rates (0.402 min−1 for hydrogenation of p-NA and 0.471 min−1 for catalytic reduction of MO) and kinetics analysis of the experimental data was found to be coherent with the pseudo-first order model, thereby implying that the catalysis proceeded through the Langmuir–Hinshelwood mechanism. Thus the obtained experimental results highlight the utility and viability of synthesized MMO as an efficacious and sustainable catalytic material. [ABSTRACT FROM AUTHOR]

Cisplatin (CDDP) is an FDA‐approved chemotherapeutic drug used for treating various solid tumors. Despite of its effectiveness towards chemotherapy, it faces several challenges, such as multi‐drug resistance (MDR) and significant damage to the normal tissues. To address these challenges, various nanoformulations were developed to improve the delivery and safety of CDDP. One of the limitation in these CDDP loaded nanoformulations is that the effective CDDP loading concentrations are very poor. Therefore, this leaves a grand challenge to develop an effective strategy to carry higher concentrations of CDDP molecules, and also simultaneously exhibit very unique properties. Herein, we have developed an one‐pot synthesis of Cisplatin encapsulated Plasmonic blackbody (CiP), which offers a double play for near infrared (NIR) light activatable chemo‐photothermal therapy in destructing cancer cells as well as mediate catalytic reduction of 4‐nitrophenol (4‐NP). The CiP nanoformulation exhibits superior light absorbing capabilities in the NIR region with an appreciable photothermal conversion efficiency of 41 %. Further, NIR light activatable combinatorial therapeutic approach of CiP was demonstrated against ovarian cancer cells and as a catalyst for the reduction of model pollutant 4‐nitrophenol. Our findings highlight the potential of CiP as a versatile platform for light‐activated combinatorial cancer therapy and environmental pollutant remediation. [ABSTRACT FROM AUTHOR]

7-Methyladenine is a biomarker of DNA damage from exposure to methylating agents. Also, it is a partial agonist for the G protein-coupled receptor in rats. So far, the reported synthetic methods for 7-methyl-adenine are not convenient enough. We herein report an improved four-step synthesis of 7-methyladenine via cyanation, Raney Ni catalytic reduction, cyclization, and bis(pinacolato)diboron (Bpin)2 reduction. The advan-tages of this procedure include the avoidance of precious metal catalysts, simple operation, and good yields. [ABSTRACT FROM AUTHOR]

The reactivity of nitrogen oxide, NO, as a ligand in complexes with [Fe2-S2] and [Co2-S2] non-planar rhombic cores is examined by density functional theory (DFT). The cobalt-containing nitrosyl complexes are less stable than the iron complexes because the Co-S bonds in the [Co2-S2] core are weakened upon NO coordination. Various positions of NO were examined, including its binding to sulfur centers. The release of NO molecules can be monitored photochemically. The ability of NO to form a (NO)2 dimer provides a favorable route of electrochemical reduction, as protonation significantly stabilizes the dimeric species over the monomers. The quasilinear dimer ONNO, with trans-orientation of oxygen atoms, gains higher stability under protonation and reduction via proton–electron transfer. The first two reduction steps lead to an N2O intermediate, whose reduction is more energy demanding: in the two latter reaction steps the highest energy barrier for Co2S2(CO)6 is 109 kJ mol−1, and for Fe2S2(CO)6, it is 133 kJ mol−1. Again, the presence of favorable light absorption bands allows for a photochemical route to overcome these energy barriers. All elementary steps are exothermic, and the final products are molecular nitrogen and water. [ABSTRACT FROM AUTHOR]

Nanowire‐MnO2 and a series of Zr‐doped MnO2 catalysts with different Zr/Mn molar ratios were successively prepared by hydrothermal and impregnation methods. The Zr‐doped MnO2 catalyst with Zr/Mn molar ratio of 0.04 and calcination temperature of 400 °C, proved to be the optimal that possessed the highest low‐temperature denitration efficiency. It showed the NO conversion of ~92 % and N2 selectivity of ~80 % at 150 °C. Characterization results demonstrated that the main active phase of the catalyst was β‐MnO2, Zr atoms interacted with Mn atoms, and Zr doping increased the structural defects, oxygen vacancies and weak acid sites, which effectively enhanced the low‐temperature denitration activity and N2 selectivity of β‐MnO2, also improved the water and sulphur resistance to some extent. [ABSTRACT FROM AUTHOR]

Tetrapyrrolic containing metal complexes are among the most efficient molecular catalysts for the CO2 reduction. Metalloporphyrins and phthalocyanines are currently under investigations and their catalytic properties are among the best molecular catalysts. Corrole, a contracted tetrapyrrolic macrocycle has been also used to design molecular for the CO2 reduction. The electrochemical activity towards CO2 reduction can rival those of their porphyrin analogues. However, the catalytic activity of the metallocorrole is initiated at the corresponding MII/I couple. Accordingly, a catalytic current in presence of CO2 with cobalt corrole appears when the CoI species is generated. We have designed an electron deficient A2B corrole holding two −CF3 groups and a benzonitrile in the meso positions and its cobalt complex (1). We reasoned that these groups could shuffle the redox potentials to reach the M(I) oxidation states at more positive values thereby lowering the overpotential for the catalytic CO2 reduction. Our results clearly show that catalyst 1 when adsorbed on a carbon electrode, shows the most favourable catalytic performance for CO production, achieving an efficiency of 85 % with a current density of −1.5 mA cm−2 at −1.0 V vs NHE. The current densities of controlled potential electrolysis with increasing amount of KHCO3, were found to increase more than one order of magnitude with the formation of MeOH. [ABSTRACT FROM AUTHOR]

Tetrapyrrolic containing metal complexes are among the most efficient molecular catalysts for the CO2 reduction. Metalloporphyrins and phthalocyanines are currently under investigations and their catalytic properties are among the best molecular catalysts. Corrole, a contracted tetrapyrrolic macrocycle has been also used to design molecular for the CO2 reduction. The electrochemical activity towards CO2 reduction can rival those of their porphyrin analogues. However, the catalytic activity of the metallocorrole is initiated at the corresponding MII/I couple. Accordingly, a catalytic current in presence of CO2 with cobalt corrole appears when the CoI species is generated. We have designed an electron deficient A2B corrole holding two −CF3 groups and a benzonitrile in the meso positions and its cobalt complex (1). We reasoned that these groups could shuffle the redox potentials to reach the M(I) oxidation states at more positive values thereby lowering the overpotential for the catalytic CO2 reduction. Our results clearly show that catalyst 1 when adsorbed on a carbon electrode, shows the most favourable catalytic performance for CO production, achieving an efficiency of 85 % with a current density of −1.5 mA cm−2 at −1.0 V vs NHE. The current densities of controlled potential electrolysis with increasing amount of KHCO3, were found to increase more than one order of magnitude with the formation of MeOH. [ABSTRACT FROM AUTHOR]

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The development of catalysts composed of single atoms is crucial for enhancing the performance of oxygen reduction reaction (ORR). However, the unsatisfactory intrinsic activity of these catalysts still poses a major challenge, limiting their overall effectiveness. One approach to addressing this challenge is the introduction of metal clusters, which can form a synergistic effect with the single atoms, ultimately improving their performance. In this study, core‐shell structured carbon polymer is constructed with Zn atoms and Sn nanoclusters by directly subjecting pyrolysis of the covalent organic polymer (COP) and metal organic framework (MOF) (COP@MOF). The thin COP shell serves a dual purpose: it prevents the collapse and aggregation of zeolitic imidazolate framework‐8 (ZIF‐8) and promotes the formation of mesopores, facilitating mass transport and enhancing the graphitization degree to improve conductivity. The resulting Sn‐COP@MOF800 exhibits promising catalytic performance in the ORR, demonstrating a half‐wave potential of 0.81 V and current density of 5.56 mA cm−2 in 0.1 m KOH, which is comparable to that of Pt/C. This study provides new ideas for exploring the application of metal single atoms and metal nanoclusters in ORR catalysis through synergistic effects. [ABSTRACT FROM AUTHOR]

A novel La/O co‐doped SnS oxysulfide catalyst (labeled SnLaOS) with heterovalent tin states and sulfur vacancy defects is successfully synthesized for effective catalytic reduction of toxic organics heavy metal ions with NaBH4 in the dark. La/O co‐doped and hydrogen peroxide‐driven SnLaOS catalyst with suitable heterovalent Sn2+/Sn4+ states and sulfur vacancy defects exhibited excellent catalytic reduction capability. The 100 mL 20 ppm of 4‐nitrophenol (4‐NP) and 50 ppm of rhodamine‐B (RhB), methylene blue (MB), methyl orange (MO), and Cr(VI) solution are entirely reduced by 5 mg SnLaOS‐3 within 10, 12, 12, 16, and 14 min, respectively, with durable stability. Synergistic transition metal La3+‐cation and O2−‐anion co‐doped SnS adjusted the energy bandgap and introduced sulfur vacancy defects, and the hydrogen peroxide‐driven regulated the SnLaOS with suitable Sn4+/Sn2+ states ratio. The sulfur vacancies in SnLaOS provide active sites for adsorbed proton for pollutants reduction, and heterovalent Sn2+/Sn4+ states in SnLaOS facilitates electrons efficient transfer through electron hopping between Sn2+ and Sn4+ for pollutants reduction. This study provides a novel efficient catalyst for the water pollutants treatment. [ABSTRACT FROM AUTHOR]

When platinum-containing diesel oxidation catalysts (DOC) are exposed to high temperatures under lean conditions, the platinum nanoparticles form volatile platinum dioxide on the catalyst surface. The exhaust flow carries the volatile platinum dioxide to the downstream aftertreatment catalyst, such as the selective catalytic reduction (SCR) catalyst, that is responsible for reducing the nitrogen oxides (NOx) emissions and can negatively impact its performance, by promoting the parasitic oxidation of ammonia. Here we investigate the factors such as exposure time, temperature and DOC design characteristics for their impact on the platinum dioxide migration, by characterising the amount of platinum deposited on the SCR catalyst at very low levels (<5 ppm), using inductively coupled plasma optical emission spectroscopy (ICP-OES) fire assay technique. Our results indicate that welldispersed platinum, not associated with palladium, is most prone to platinum dioxide migration. We also compare several methods to suppress the platinum dioxide migration from the DOC, such as sintering of the platinum nanoparticles, stabilising the platinum nanoparticles via interaction with palladium or covering the platinum nanoparticles with a high surface area capture layer to trap the volatile platinum dioxide. [ABSTRACT FROM AUTHOR]

Abstract Layered double hydroxides (LDHs) can serves as catalysts for CO2 photocatalytic reduction (CO2PR). However, the conventionally synthesized LDHs undergo undesired aggregation, which results in an insufficient number of active sites and limits the desirable electron transfer required for CO2PR. The metal‐organic framework (MOF) template‐grown LDHs demonstrate excellent promise for exploiting the strengths of both MOFs and LDHs. Herein, the in situ growth of MIL‐68(In)‐NH2 MOF‐templated Co–In bimetallic catalyst (CoIn‐LDH/MOF) having an ultrathin nanosheet morphology on the preserved rod‐like MOF template is demonstrated. Compared to the conventionally grown bimetallic LDH (CoIn‐LDH), CoIn‐LDH/MOF not only exposes more active sites but also possesses hydroxyl vacancies (VOH) and Co vacancies (VCo). Thus, CoIn‐LDH/MOF performs a higher CO generation rate of 2320 µmol g−1 h−1 during CO2PR, demonstrating improved activity and selectivity than those in CoIn‐LDH. Experiments coupled with calculations reveal that the CoIn‐LDH/MOF‐driven CO2PR follows the *COOH pathway. The lower energy barriers for the formation of *COOH and CO(g) can be attributed to the coexistence of VOH and VCo in CoIn‐LDH/MOF, effectively promoting charge transfer and enhancing CO2PR performance. This study provides a new strategy to obtain high‐performant LDH‐based catalysts with improved morphology.

Silver nanoparticles (Ag NPs) supported on natural materials have garnered significant attention due to their wide applicability across various research fields. This study presents an eco-friendly, scalable, and one-step approach to synthesizing high-purity Ag NPs supported by bentonite-graphitic carbon nitride (Bt-g-C3N4) nanocomposites via thermal reduction. The successful integration of Ag NPs into the Bt-g-C3N4 matrix was confirmed through several characterization techniques, including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), X-ray fluorescence (XRF), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive spectroscopy (EDX). XRF analysis identified the clay as beidellite-rich (Si/Al molar ratio less than 2), while EDX spectra and XRD patterns confirmed the presence of Ag NPs, with characteristic peaks at 38.04° and 44.24°. SEM and TEM images showed uniform Ag NP distribution with an average particle size of 4.75 nm and a spherical morphology. Acid-activated bentonite preserved its layered structure and exhibited a significant surface area increase, reaching 113.77 m²/g after hydrochloric acid treatment, thereby enhancing its capacity for supporting nanoparticle-based catalysts. The synthesized nanocomposites demonstrated exceptional catalytic performance, achieving reduction efficiencies of approximately 99 % for various organic pollutants, including nitrophenols (within 7 min for 4-nitrophenol), cationic dyes (within 12 min for Rhodamine B), and anionic dyes (within 5 min for methyl orange), using sodium borohydride (NaBH4) as the reducing agent. The reduction followed first-order kinetics, with activity factors (k′) calculated as 134 s−1.g−1, 260 s−1.g−1, and 92 s−1.g−1 for 4-NP, MO, and RhB, respectively. Furthermore, the Ag NPs/Bt-g-C3N4 nanocomposites exhibited remarkable recyclability, maintaining high catalytic efficiency across multiple cycles.

Abstract One of the biggest issues affecting the entire world currently is water contamination caused by textile industries’ incapacity to properly dispose their wastewater. The presence of toxic textile dyes in the aquatic environment has attracted significant research interest due to their high environmental stability and their negative effects on human health and ecosystems. Therefore, it is crucial to convert the hazardous dyes such as methyl orange (MO) azo dye into environmentally safe products. In this context, we describe the use of Copper Nitroprusside Chitosan (Cu/SNP/Cts) nanocomposite as a nanocatalyst for the chemical reduction of azodyes by sodium borohydride (NaBH4). The Cu/SNP/Cts was readily obtained by chemical coprecipitation in a stoichiometric manner. The X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FT-IR) spectroscopy were applied to investigate chemical, phase, composition, and molecular interactions. Additionally, Scanning electron microscope (SEM) was used to examine the nanomaterial's microstructure. UV–vis spectroscopy was utilized for studying the Cu Nitroprusside Chitosan's catalytic activity for the reduction of azodye. The Cu/SNP/Cts nanocomposite demonstrated outstanding performance with total reduction time 160 s and pseudo-first order constant of 0.0188 s−1. Additionally, the stability and reusability study demonstrated exceptional reusability up to 5 cycles with minimal activity loss. The developed Cu/SNP/Cts nanocomposite act as efficient nanocatalysts for the reduction of harmful Methyl orange azodye.

Herein, silver phosphate nanoparticles decorated with melamine–formaldehyde polymer nanocomposite (Ag3PO4-MFP) were fabricated. The synthesized nanocomposite was assessed for the catalytic reduction of mono, di, and tri-nitrophenols, such as p-nitrophenol (PNP), di-nitrophenol (DNP), and tri-nitrophenol (TNP), to their corresponding aminophenols (APs) using NaBH4 in an aqueous medium, particularly at ambient conditions. The % reduction of PNP, DNP, and TNP was ∼99%, ∼96%, and ∼63%, respectively. [ABSTRACT FROM AUTHOR]

The present study conducts a comparative analysis between selective catalytic reduction (SCR) using a Cu-zeolite catalyst and selective non-catalytic reduction (SNCR) for the removal of NO x from industrial waste gas. The primary objective of this investigation is to computationally explore the removal of NO x using NH3 at various reactor conditions, along with the study of different hydrodynamic aspects. The study revealed the impact of different porosity of the catalyst (in SCR) and the number of baffles (in SNCR) on the reaction and fluid flow profile. Distinct geometries were employed to model each process, incorporating a turbulent model and kinetic parameters with an eddy-dissipation model (EDM) for simulations. Analyzing the effect of the NH3/NO ratio on NO conversion efficiency is a crucial component of the study. With diminishing efficiency at higher ratios, the SCR process demonstrated nearly complete NO conversion at a certain NH3/NO ratio, and this value changes with the inlet gas temperature. In contrast, SNCR produced less favorable conversion rates than SCR, indicating that the amount of NH3 supply affects conversion efficiency. At the SCR system’s optimum NH3/NO ratio, SNCR achieved an 83 % conversion, and the conversion rate remained relatively constant as the ratio was increased. The results highlight the various possibilities for optimization of the reactor systems in terms of efficiency and economic feasibility. [ABSTRACT FROM AUTHOR]

We successfully fabricated Ag@Cu2O core–shell decorated on reduced graphene oxide (rGO) nanocomposites (ACRN) with a simple and convenient in situ substitution method. The properties of these ACRNs with heterostructure layers were characterized by scanning and transmission electron microscopy and absorption spectroscopy. We used 4-nitrophenol (4-NP) as a probe molecule to determine the chemical catalytic activity of the ACRN. Upon introduction of rGO, a high electron transfer efficiency was achieved; thus, the catalytic activity was improved significantly. Therefore, the ACRN exhibited significantly improved catalytic activity for the reduction of 4-NP and showed high application value in the removal of toxic and harmful substances from water. The catalytic efficiency was improved by 1.7 times by using the ACRN compared to Ag–rGO. In addition, the fabricated ACRN was used for the reduction of an organic dye (methyl orange, MO), and explosive pollutant (trinitrophenol, TNP) to generate nontoxic products. Furthermore, the high charge redistribution and transfer among Ag, Cu2O, and rGO in the ACRN induced the high catalytic reduction of organic pollutants, indicating the excellent potential of these materials for applications in water pollution treatment. [ABSTRACT FROM AUTHOR]

Selective catalytic reduction of nitrogen oxides (NOx) with ammonia (NH3-SCR) has been implemented in response to the regulation of NOx emissions from stationary and mobile sources above 300 °C. However, the development of NH3-SCR catalysts active at low temperatures below 200 °C is still needed to improve the energy efficiency and to cope with various fuels. In this review article, recent reports on low-temperature NH3-SCR catalysts are systematically summarized. The redox property as well as the surface acidity are two main factors that affect the catalytic activity. The strong redox property is beneficial for the low-temperature NH3-SCR activity but is responsible for N2O formation. The multiple electron transfer system is more plausible for controlling redox properties. H2O and SOx, which are often found with NOx in flue gas, have a detrimental effect on NH3-SCR activity, especially at low temperatures. The competitive adsorption of H2O can be minimized by enhancing the hydrophobic property of the catalyst. Various strategies to improve the resistance to SOx poisoning are also discussed. [ABSTRACT FROM AUTHOR]

Phenylhydroxylamine and its derivates (PHAs) are important chemical intermediates. Phenylhydroxylamines are mainly produced via the catalytic reduction of aromatic nitro compounds. However, this catalytic reduction method prefers to generate thermodynamically stable aromatic amine. Thus, designing suitable catalytic systems, especially catalysts to selectively convert aromatic nitro compounds to PHAs, has received increasing attention but remains challenging. In this review, we initially provide a brief overview of the various strategies employed for the synthesis of PHAs, focusing on reducing aromatic nitro compounds. Subsequently, an in-depth analysis is presented on the catalytic reduction process, encompassing discussions on catalysts, reductants, hydrogen sources, and a comprehensive assessment of the merits and drawbacks of various catalytic systems. Furthermore, a concise overview is provided regarding the progress made in comprehending the mechanisms involved in this process of catalytic reduction of aromatic nitro compounds. Finally, the main challenges and prospects in PHAs' production via catalytic reduction are outlined. [ABSTRACT FROM AUTHOR]

Ammonia (NH3) is a crucial industrial raw material, but the traditional Haber-Bosch process is energy-intensive and highly polluting. Electrochemical methods for synthesizing ammonia using nitric oxide (NO) as a precursor offer the advantages of operating under ambient conditions and achieving both NO reduction and resource utilization. Defect engineering enhances electrocatalytic performance by modulating electronic structures and coordination environments. In this brief review, the catalytic reaction mechanism of electrocatalytic NO reduction to NH3 is elucidated, with a focus on synthesis strategies involving vacancy defects and doping defects. From this perspective, the latest advances in various catalytic reduction systems for nitric oxide reduction reaction (NORR) are summarized and synthesized. Finally, the research prospects for NO reduction to NH3 are discussed. [ABSTRACT FROM AUTHOR]

Selective catalytic reduction (SCR) technology is the main means of reducing NO X emissions. Urea injection structure parameters (i.e., the hole number in a nozzle, spray angle, the distance between the nozzle and the front section of the catalyst) and operating parameters (i.e., exhaust gas temperature, gas hourly space velocity, ammonia-to-nitrogen ratio (ANR)) of the SCR systems have a significant impact on denitrification efficiency (deNO X). A three-dimensional simulation model is developed to investigate the impact of diverse parameters on deNO X. The influence of temperature, ANR and space velocity on the deNO X of SCR system is studied by using the control variable method. The simulation model is modified according to the SCR catalyst gas distribution test results. A diesel bench experiment is conducted to test the deNO X of the SCR system of D2 cycle and two additional operating points to verify the accuracy of the numerical simulation model. Based on this model, the influence of key factors on the deNO X of SCR system is studied. In SCR system, the optimal urea injection angle is about 75°, the optimal number of nozzle holes is 4, the distance between the optimal urea injection point and the front section of the catalyst is 8 times of the pipe diameter, and the optimal operating temperature is 300 ∼ 420℃. The influence trend of ANR on deNO X at different temperatures is obtained. This provides a theoretical support for the realization of SCR system in the future. • The factors influencing the denitrification efficiency (deNO X) of SCR were studied. • Both experimental research and numerical simulation were combined for this study. • When the injection angle of urea was 75 degrees, the atomization effect was the best. • The optimal temperature range for the SCR reaction was between 270°C and 420°C. • DeNO X in the high-temperature range was essentially unaffected by the gas hourly space velocity. [ABSTRACT FROM AUTHOR]

Ammonia (NH3) is a crucial industrial raw material, but the traditional Haber-Bosch process is energy-intensive and highly polluting. Electrochemical methods for synthesizing ammonia using nitric oxide (NO) as a precursor offer the advantages of operating under ambient conditions and achieving both NO reduction and resource utilization. Defect engineering enhances electrocatalytic performance by modulating electronic structures and coordination environments. In this brief review, the catalytic reaction mechanism of electrocatalytic NO reduction to NH3 is elucidated, with a focus on synthesis strategies involving vacancy defects and doping defects. From this perspective, the latest advances in various catalytic reduction systems for nitric oxide reduction reaction (NORR) are summarized and synthesized. Finally, the research prospects for NO reduction to NH3 are discussed. [ABSTRACT FROM AUTHOR]