Improve Reaction Efficiency Research Articles

Photosensitizer-Free Benzo[1,4]oxazin-2-one Synthesis by Continuous-Flow Photochemistry.

We report a photosynthetic method for producing 2H-benzo[b][1,4]oxazin-2-ones from aryl azides and α-ketoacids. This method is highly sustainable, requiring only visible light irradiation of the substrates and no external additives. Furthermore, we implemented a continuous-flow system to achieve efficient light irradiation and rapid mixing, significantly improving reaction efficiency and reducing reaction time compared to the batch process. The flow system enabled gram-scale synthesis. We also demonstrated the utility of the products, by employing the benzo[1,4]oxazin-2-one moiety as a directing group for C-H activation on the 3-aryl substituent. This green approach highlights the potential for developing environmentally friendly synthetic processes.

Development and Application of Green Catalysts: Challenges, Optimization, and Future Perspectives

This paper comprehensively reviews the development and application of green catalysts in modern chemical industries, with a focus on analyzing the significant advantages of various types of green catalysts, such as metal-organic frameworks (MOFs) and enzyme catalysts, in improving reaction efficiency, reducing energy consumption, and minimizing by-product generation. The paper delves into the design and synthesis of green catalysts, optimization of reaction conditions, and technologies for catalyst recycling and regeneration, highlighting their key roles in enhancing catalyst performance. Despite challenges such as high material costs, complex synthesis processes, and issues with stability and durability in practical applications, continuous technological innovation and process improvements offer promising solutions. As global attention to sustainable development grows, green catalysts are expected to have broad applications in emerging fields such as carbon capture and utilization, renewable energy conversion, and environmental remediation, thereby driving the green transformation and low-carbon development of the chemical industry and providing strong technical support for achieving global sustainability goals.

Trace Iron-Modified CeO₂-supported Core-shell CoO@Co Catalyst for Selective Conversion of Furfural to 1,5-Pentanediol.

In the conversion of furfural using non-noble metal catalysts, preferential cleavage of the C2-O bond followed by hydrogenation of the C=C bond facilitates selective access to valuable 1,5-pentanediol (1,5-Ped). Herein, we developed CeO₂ loaded core-shell CoO@Co nanoparticle catalysts. Adjusting Co loading, Fe doping, and reduction temperature improved reaction efficiency. 7Co-0.2Fe/CeO₂ catalysts reduced at 500 °C demonstrated optimal performance. 1,5-Ped produced at 54.76 mmol/g(Co)/h, representing the top activity levels among the reported catalysts. H₂-TPR, XRD, HAADF-STEM, FT-IR, XPS, and XANES were employed to investigate the catalyst structure-activity relationship. Co²⁺ cleaves furan ring C-O bond, Co⁰ promotes double-bond hydrogenation. The CoO@Co structure favors the desired 1,5-Ped production route. Trace Fe species optimize the Co²⁺/Co⁰ ratio, enhance the substrate adsorption, and inhibit the furan ring saturation. These findings emphasize the importance of fine-tuning catalyst structure and composition for selectivity improvement.

Apparent kinetics study and efficient continuous-flow synthesis of tert-butyl hydroperoxide & tert-butyl peroxybenzoate in a microreaction system

This study advances the synthesis of tert-butyl hydroperoxide (TBHP) and tert-butyl peroxybenzoate (TBPB) using a continuous microreaction system, meticulously detailing kinetic behavior and optimization processes through over 1250 experimental data points. We have developed a platform capable of high-throughput kinetic experiments and precise reaction quenching, determining kinetic parameters and optimal conditions that significantly improve reaction efficiency and safety. Tailored microreaction strategies, including micro-mixers, plate microreactors, and micro-packed beds, were employed to manage exothermic reactions and enhance mass transfer for each peroxide. For TBHP, conditions were optimized to achieve a 99% conversion rate of tert-butanol and an 82% conversion of hydrogen peroxide, with product selectivity reaching 92%. For TBPB, under optimal conditions, benzoyl chloride conversion reached 99.5%, and TBHP conversion was 80%, with a product selectivity of 94%. The integration of the TBHP and TBPB synthesis processes into a single continuous-flow system demonstrates scalable, safe, and efficient production, highlighting significant potential for advancements in organic peroxide manufacturing.

Synergistic Coordination and Surface Plasmon Resonance of Quantum Dots in Enhancing Photocatalytic Hydrogen Evolution.

Recent studies have revealed that the integration of metal nanoparticles (NPs) with photocatalysts allows the metal NPs to serve as cocatalysts, significantly enhancing reactant efficiency near nanostructures through the surface plasmon resonance (SPR) effect. On this basis, we synthesized highly reactive FePt quantum dots (FePt QDs) with tailored configurations, manipulating the Pt coordination environment and combining FePt QDs with ultrathin two-dimensional nickel metal-organic layer (Ni-MOL) nanosheets. X-ray absorption fine spectroscopy (XAFS) confirmed the distinctive Pt-Fe configuration after photoactivation. The optimized loading amount of FePt QDs led to a hydrogen evolution reaction (HER) yield of 113 mmol·g-1·h-1 after activation, with the catalyst remaining stable over five cycles. The improved reaction efficiency stemmed from Pt coordination adjustments and a localized SPR effect, supported by ultraviolet-visible (UV-vis), infrared (IR), Raman, and XAFS characterizations. A comparative analysis was conducted with Ni-MOL deposited with platinum NPs, further underscoring the distinct advantages of FePt QDs and corroborating by density functional theory (DFT) calculations, which revealed favorable d-band center properties. These findings offer a promising avenue for the development of highly efficient and stable nanoalloy photocatalysts.

Continuous Flow Microreactors for the High-efficiency Enzymatic Synthesis of 10-Hydroxystearic Acid from Oleic Acid.

Converting fatty acids into specialty chemicals is sustainable but hindered by the low efficiency and thermal instability of current oleic acid hydratases, along with mass transfer limitations in emulsion reactions. This study introduces an optimized continuous flow micro-reactor (CFMR) that efficiently transforms oleic acid at low (15 g L-1) and high (50 g L-1) concentrations, improving reaction efficiency and overcoming key conversion barriers. The first CFMR model showed reaction speeds surpassing traditional batch stirred tank reactors (BSTR). Optimizations were performed on three key components: liquid storage, mixer, and reaction section of the CFMR, with each round's best conditions carried into the next. This achieved a space-time yield of 597 g L-1 d-1 at a 15 g L-1 oleic acid load. To further enhance the yield, we optimized the emulsifier system to solve incomplete emulsification and developed a two-component feed microreactor (TCFMR) that addressed mass transfer limitations caused by the product at high substrate loads, reaching a 91 % conversion of 50 g L-1 oleic acid in 30 minutes, with a space-time yield of 2312 g L-1 d-1. These advancements represent significant progress in utilizing fatty acids and advancing sustainable chemical synthesis.

Bio‐Inspired Cu/Pd Bimetallic Catalysts Facilitating One‐Pot Relay Catalysis of Homo‐Couplings of Arylboronic Acids

ABSTRACTInspired by the multienzymatic relay catalysis in nature, herein, we reported a pioneering bio‐inspired Cu/Pd bimetallic composite microspheres (Cu/CMC@Pd/C) as a simple and efficient relay catalyst for the homo‐coupling of arylboronic acids. In this composite, Pd/C was encapsulated by Cu(II)‐crosslinking carboxymethyl cellulose (Cu/CMC). Cu/CMC@Pd/C microspheres were easily achieved by adding a mixture solution of Pd/C and carboxymethyl cellulose into a Cu(II) solution through an ion exchange reaction between carboxylate groups of CMC and Cu(II) ions. The morphology and composition of the as‐prepared Cu/CMC@Pd/C microspheres were well characterized using various analytical tools such as FT‐IR, XRD, XPS, SEM, TEM, elemental mapping, EDS, and ICP‐AES. The analysis indicated that the composite microspheres have a porous structure and Pd/C is uniformly distributed within the interior of the composite microspheres. The porous structure facilitates mass transfer of the substrate and increases the contact area of the catalyst, thus improving reaction efficiency. The performance of Cu/CMC@Pd/C microspheres was assessed in the homo‐coupling of arylboronic acid for the synthesis of symmetric biaryl without the need for an aryl halide as a partner. This process mimics a multienzyme catalysis through a relay Cu(I)‐catalyzed halogenation of one portion of arylboronic acid and a Pd(0)‐catalyzed Suzuki–Miyaura cross‐coupling between the in situ generated aryl halide and another portion of arylboronic acid. The results showed that this bio‐inspired Cu/CMC@Pd/C has excellent relay catalytic activity with tolerance of broad functional groups, producing the desired symmetrical biaryls in excellent yields within a short reaction time under mild conditions. Moreover, the catalyst can be easily recovered through simple filtration and still has good catalytic activity after six cycles. Consequently, this innovative pseudo‐homogeneous Cu/Pd relay catalyst emerges as a convenient and efficient alternative for the synthesis of asymmetric biaryls.

Control of burning rate pressure sensitivity for solid propellants by changing the interfacial contact of Al/HMX/AP with precisely located graphene-based energetic catalysts

The control of burning rate pressure sensitivity is essential for stable and reliable combustion of solid propellants. It has been proved that the combustion behavior of propellants can be effectively tuned by interfacial control of Al/oxidizers. In this work, core-shell Al-based composites, using oxidizers such as ammonium perchlorate (AP) and cyclotetramethylene tetranitramine (HMX) as the shell layer, have been prepared with a well-controlled location of graphene-based carbohydrazide complexes (GO-CHZ-M, M = Co2+ or Ni2+) as the catalysts. The catalysts can be located inside HMX or embedded on the surface of AP particles. The decomposition of AP and HMX could be greatly promoted with a trace amount of catalyst. Under the synergistic effects of Al/oxidizer interfacial control and GO-CHZ-M, the ignition delay time is shortened by >48 % with increased in flame radiation. More importantly, the burning rate (r) and pressure exponent (n) of the solid propellants are effectively regulated in a wide range. In particular, the use of Al@HMX/Co results in a lowered n of 0.29 within 1∼20 MPa compared to 0.79 for the blank reference sample. The agglomeration of Al particles during combustion was also inhibited due to the micro-explosion effect of Al@HMX composites. Novelty and Significance statementThe innovative approaches of integrating Al/HMX/AP composites and precise catalysis of graphene-based energetic catalysts in solid propellants have successfully achieved, regarding the modulation of the burning rates and pressure sensitivity. Moreover, the effect of catalyst location on the ignition delay and burning rates has also been studied thoroughly and clarified. This paper provides new insight into the regulation of combustion performance of solid propellants, with improved reaction efficiency and maintained energy density.

A Simple Approach for Modulating the Active Site in Fe-Based Electrocatalysts

Proton Exchange Membrane Fuel Cells (PEMFCs) have garnered attention as a next-generation, environmentally friendly energy solution to address issues like the climate crisis and depletion of fossil fuels resulting from excessive usage. Nevertheless, the commercialization of PEMFCs faces challenges due to the use of expensive platinum catalysts for the Oxygen Reduction Reaction (ORR). In contrast, Anion Exchange Membrane Fuel Cells (AEMFCs) offer advantages by utilizing cost-effective non-platinum catalysts, making ongoing research on non-platinum catalysts for AEMFCs essential. Numerous studies have been conducted to develop M-N-C catalysts in nanoparticle units using transition metals such as Fe, Co, and Ni for AEMFCs. Notably, Fe-based catalysts with FeNx active sites are considered representative candidates for AEMFCs. Moreover, recent research aims to advance Fe catalysts by incorporating single-atom active sites to enhance mass transfer and improve reaction efficiency at the atomic level.We have developed a straightforward method for synthesizing an Fe catalyst. The catalyst, synthesized through a redox reaction between aniline and a metal ion, followed by pyrolysis, exhibited remarkable durability and activity for the Oxygen Reduction Reaction (ORR). Notably, it possesses an active FeNx site crucial for ORR. Furthermore, by simply altering the solvent during the synthesis process, we observed a variation in the Fe-to-N ratio. Particularly noteworthy was the synthesis of Fe4N, which demonstrated activity for the Oxygen Evolution Reaction (OER). This synthesis method allows for the controlled manipulation of the catalyst's chemistry by varying the solvent, resulting in the production of Fe-based catalysts with either FeNx or Fe4N active sites, active for ORR and OER, respectively. To understand the catalyst's characteristics based on the solvent used during synthesis, we conducted a comprehensive characterization using techniques such as Thermogravimetric Analysis (TGA), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). The electrochemical activity was investigated through a half-cell test, and efforts were made to interpret the results based on the catalyst's properties.

Promoting the OH cycle on an activated dynamic interface for electrocatalytic ammonia synthesis

Renewable-driven electrocatalytic nitrate conversion offers a promising alternative to alleviate nitrate pollution and simultaneously harvest green ammonia. However, due to the complex proton-electron transfer processes, the reaction mechanism remains elusive, thereby limiting energy efficiency. Here, we adopt Ni(OH)₂ as a model catalyst to investigate the dynamic evolution of the reaction interface. A proposed OH cycle mechanism involves the formation of a locally OH-enriched microenvironment to promote the hydrogenation process, which is identified through in-situ spectroscopy and isotopic labelling. By further activating the dynamic state through the implementation of surface vacancies via plasma, we achieve a high Faradaic efficiency of almost 100%. The activated interface accelerates the OH cycle by enhancing dehydroxylation, water dissociation, and OH adsorption, thereby promoting nitrate electroreduction and inhibiting hydrogen evolution. We anticipate that rational activation of the dynamic interfacial state can facilitate electrocatalytic interface activity and improve reaction efficiency.

Photoexcitation Altered Reaction Pathway Greatly Facilitate Ammonia Synthesis Over Isolated Ru Sites

AbstractAmmonia, poised as a carbon‐neutral energy carrier, holds immense promise in reshaping the future energy landscape. Despite the enduring importance of the Haber–Bosch process in ammonia production, its substantial carbon emissions and energy demands necessitate more sustainable pathways. Here, an advanced ammonia synthesis route, enhanced by photoexcitation is demonstrated, which fundamentally modifies the activation pathways of N2 molecules. This alteration significantly lowers the reaction activation energy, resulting in remarkably improved reaction efficiency. The impact of light excitation culminates in an unprecedented ammonia synthesis rate of 18 mmol g−1 h−1, surpassing the traditional thermal catalytic process by 2.57‐fold. More importantly, light assistance reduces the thermal energy input by ≈16%, making it comparable to thermal catalysis while substantially improving energy utilization. This work introduces a greener strategy for ammonia synthesis, pushing the century‐old fossil‐fueled Haber–Bosch process to a new frontier.

Highly Selective Isomerization of Glucose to Fructose through a Biphasic and Recyclable Mimetic Enzyme Catalyst

AbstractDeveloping a biphasic catalyst is of great significance for improving reaction efficiency and its industrial application. Herein a novel biphasic catalyst containing three functional groups of chlorophenol, amino and carboxyl was synthesized and used as mimic glucose isomerase to catalyze the isomerization. The mimic enzyme exhibited excellent catalytic performance for isomerization of glucose to fructose under mild conditions. Temperature and pH of solution showed significant influence on the conversion of glucose and the selectivity of fructose. The yield and selectivity of fructose reached 32.4 % and 91.0 % after reacting 2 h, respectively, at pH 9.5 and 90 °C. The solubility of the catalyst exhibited dual sensitivity to both pH and temperature. The catalyst was in a soluble state during the reaction process and could be precipitated by reducing the pH and temperature of the reaction system. The catalyst could be reused and still maintained good catalytic activity after five consecutive cycles.

Confinement-enhanced electrochemiluminescence by Ru(dcbpy)32+-functionalized γ-CD-MOF@COF-LZU1 porous hybrid material as micro-reactor for CYFRA 21-1 detection

The improvement of electrochemiluminescence (ECL) performance relies on the electron transfer efficiency between luminophore and coreactant. An ultrasensitive ECL micro-reactor with confinement-enhanced performance was prepared by using the covalent organic framework-LZU1-functionalized metal-organic framework (MOF@COF-LZU1) as a platform to assemble enormous N,N-dibutyl-2-hydroxyethylamine (DBAE) and tris(4,4′-dicarboxylic acid-2,2′-bipyridyl) ruthenium(II) [Ru(dcbpy)32+] into its pore channels. Compared to individual substances of γ-CD-MOF and COF-LZU1, the synergistic effects can conduce to the enhancement of the intensity, durability and sensitivity of the micro-reactor. Besides, COF-LZU1 can provide a mild environment to accommodate a certain amount of DBAE by concentrating them from the aqueous solution into its hydrophobic cavities and boost the oxidation efficiency of DBAE to generate more DBAE●+ and profited the survival of DBAE●, leading to an improved reaction efficiency with the Ru(dcbpy)32+ intermediate. Thanks to the confinement-enhanced strategy, engineered as high-functioning luminescent materials, Ru@γ-CD-MOF@COF-LZU1 micro-reactors decorated with Au NPs can facilitate electron transfer and capture primary antibodies (Ab1). Moreover, Au–Pd–Pt noble metal aerogels (NMAs) functionalized MoS2 NFs (Au–Pd–Pt NMAs@MoS2 NFs) were chosen as base material due to its large specific surface areas, high porosity, and excellent electrical conductivity. Based on above merits, the sensor demonstrated a sensitive response to CYFRA 21-1 detection in a linear concentration gradient from 10 fg/mL to 50 ng/mL with a detection limit of 0.0055 pg/mL (S/N = 3). The COF-LZU1 decorated ECL micro-reactors were constructed based on the signal amplification strategies to realize accurate CYFRA 21-1 detection.

Electrolyte design for the manipulation of gas bubble detachment during hydrogen evolution reaction

During electrochemical gas evolution reactions, the continuous and vigorous formation of gas bubbles hugely impacts the efficiency of the underlying electrochemical processes. In particular, enhancing the detachment of gas bubbles from the electrode surface has emerged as an effective strategy to improve reaction efficiency. In this study, we demonstrate that the detachment of H2 gas bubbles can be controlled by the electrolyte composition, which can be optimized. We employ a well-defined Pt microelectrode and utilize electrochemical oscillation analysis to elucidate the features of H2 gas bubble detachment. Our investigation explores how the behaviour of H2 gas bubbles responds to variations in electrolyte composition and concentration. The coalescence efficiency of electrochemically generated microbubbles, a critical factor determining the mode of H2 gas bubble detachment (random detachment vs. single H2 gas bubble detachment), is profoundly influenced by the electrolyte composition. Specifically, coalescence efficiency follows the Hofmeister series concerning anions and coalescence is consistently inhibited in the presence of alkali metal cations. Furthermore, we establish a comprehensive model that accounts for both thermal and solutal Marangoni effects, allowing us to rationalize the trend of detachment size and period of single H2 gas bubbles under various conditions.

Dielectric barrier discharge combined with Fe(III)-NTA activated persulfate for efficient degradation of enrofloxacin in water

ABSTRACT Enrofloxacin (ENR) is widely used in aquaculture due to its broad-spectrum activity against a large number of pathogenic bacteria. However, ENR exhibits strong adsorption and a low biodegradation rate in the environment. This study proposes a new method for degrading ENR, which combines dielectric barrier discharge (DBD) with advanced oxidation of peroxymonosulfate (PMS, HSO5 −) and the use of nitrilotriacetic acid (NTA) combined with Fe(III) activator to improve reaction efficiency. The effects on the degradation efficiency were experimentally investigated by adjusting the internal process parameters and adding coexisting substances. The ESR and free radical scavenging experiments showed that both hydroxyl and sulfate radicals contributed to the degradation of the pollutant ENR. Based on the identified intermediates, and three possible degradation pathways were suggested. And the intermediates were less harmful. In conclusion, the Fe(III)-NTA/PMS/DBD system may be an efficient, environmentally friendly and new technology with development potential.

An Update on Recent Green Synthetic Approaches to Coumarins

Abstract: Coumarin and its derivatives are privileged heterocyclic motifs and important building blocks for developing the biologically active compound due to its significant role in the development of new drugs. As a result, many methodologies have been developed to synthesize this important class of compounds. However, some methods are associated with toxic and corrosive catalysts, longer reaction time, poor yield, less purity, and by-products along with the desired product. In order to minimize the utilization and generation of toxic organic substances, green synthetic methods are applied in this manner. Green chemistry methods cover a wide range of methods, including the application of ultrasound and microwaves, ionic liquids and deep eutectic solvents, solvent-free and catalyst-free synthesis, and mechanosynthesis. These green synthetic methods have successfully performed all typical condensation reactions for coumarin synthesis like Knoevenagel, Perkin, Kostanecki-Robinson, Pechmann, and Reformatsky reactions. Compared to conventional methods, these methods not only minimize the use and generation of harmful chemicals but also improve reaction efficiency in terms of product yields, purity, energy consumption, and post-synthetic procedures. Due to the implication of coumarin (2-oxo-2H-1-benzopyran) backbone as a biologically active ubiquitous fragment and the recent demands of reducing toxic solvents, catalysts, and energy consumption, this review summarized various green synthetic methods for coumarin synthesis. Moreover, researchers working on this coumarin scaffold synthesis can find handy information from this review on the green synthetic approaches to their synthesis.

A novel starch-active lytic polysaccharide monooxygenase discovered with bioinformatics screening and its application in textile desizing

BackgroundLytic polysaccharide monooxygenases (LPMOs) catalyzing the oxidative cleavage of different types of polysaccharides have potential to be used in various industries. However, AA13 family LPMOs which specifically catalyze starch substrates have relatively less members than AA9 and AA10 families to limit their application range. Amylase has been used in enzymatic desizing treatment of cotton fabric for semicentury which urgently need for new assistant enzymes to improve reaction efficiency and reduce cost so as to promote their application in the textile industry.ResultsA total of 380 unannotated new genes which probably encode AA13 family LPMOs were discovered by the Hidden Markov model scanning in this study. Ten of them have been successfully heterologous overexpressed. AlLPMO13 with the highest activity has been purified and determined its optimum pH and temperature as pH 5.0 and 50 °C. It also showed various oxidative activities on different substrates (modified corn starch > amylose > amylopectin > corn starch). The results of enzymatic textile desizing application showed that the best combination of amylase (5 g/L), AlLPMO13 (5 mg/L), and H2O2 (3 g/L) made the desizing level and the capillary effects increased by 3 grades and more than 20%, respectively, compared with the results treated by only amylase.ConclusionThe Hidden Markov model constructed basing on 34 AA13 family LPMOs was proved to be a valid bioinformatics tool for discovering novel starch-active LPMOs. The novel enzyme AlLPMO13 has strong development potential in the enzymatic textile industry both concerning on economy and on application effect.

The fabrication and application of a triphasic reaction interface based on superwettability for improved reaction efficiency

This review concentrates on recent developments in the application of triphasic systems based on superwettability in photocatalysis, electrochemistry, and bioelectronics.

Revolutionizing the capture efficiency of ultrasensitive digital ELISA via an antibody oriented-immobilization strategy.

Bead-based digital ELISA, the most sensitive protein quantification method, has drawn much attention to exploring ultra-low abundance biomarkers in the life sciences and clinical applications. However, its major challenge refers to the low antigen capture efficiency in the immunoreaction process due to the low probability of collision between the deficient concentration of the analytes and the captured antibody-immobilized on the beads. Here, we achieved significantly improved reaction efficiency in the digital signal formation by fixing the orientation of antibodies and revealed the kinetic mechanism for the first time. A facile and fast antibody conjugation strategy that formed boronate ester complexes was designed to retain the uniform orientation of antibodies with controllable antibody density. Remarkably, the oriented immobilized antibody exhibited stronger antigen-binding capacity and faster antigen-binding speed compared to randomly immobilized antibodies, with capture efficiency increasing approximately 14-fold at 15 μg of antibody per 1 mg microbeads (0.035 antibody nm-2) under 0.5 h incubation. Combined with theoretical analysis, we verified that the improved capture efficiency of the oriented antibodies mainly originated from the considerable rise in the binding rate constant (kon) rather than the increase in antigen-binding sites, which further prominently decreased the limit of detection (LoD) in a shorter incubation time compared with the randomly immobilized antibody. In conclusion, the antibody oriented conjugation method effectively overcomes the low capture efficiency challenge of bead-based digital ELISA. It paves a promising way for further improving the digital immunoassay performance and promotes the early diagnosis of diseases by recognizing more ultra-low abundance significant biomarkers.

Promoting the NH3-SCR performance of Fe2O3-TiO2 catalyst through regulation of the exposed crystal facets of Fe2O3

Iron oxide (Fe2O3)-based catalysts have garnered significant attention in the field of selective catalytic reduction with NH3 (NH3-SCR) due to their high thermal stability, N2 selectivity, low cost, and environmental friendliness. In this study, Fe2O3 catalysts with exposed {012}, {014}, and {113} facets were successfully synthesized using a hydrothermal method. Subsequently, TiO2 was loaded to construct Fe2O3-TiO2 catalysts with different crystal facets of Fe2O3. The results demonstrated that TiO2 was uniformly distributed on three different morphologies of Fe2O3. Among the catalysts, the Fe2O3{113}-TiO2 exhibited superior NOx removal capacity and a broader temperature operating range than Fe2O3{012}-TiO2 and Fe2O3{014}-TiO2. The promotion mechanism of NH3-SCR performance was determined by regulating the crystal facets of Fe2O3 in Fe2O3-TiO2 catalysts. The mechanism can be attributed to the improved redox properties, as well as the presence of additional active oxygens, surface acid sites, and adsorbed nitrate species on the Fe2O3{113}-TiO2 catalyst. In situ DRIFTS results indicated that the SCR reactions of Fe2O3-TiO2 catalysts with different crystal facets of Fe2O3 followed both the Langmuir-Hinshelwood and Eley-Rideal mechanisms. Furthermore, the Fe2O3{113}-TiO2 catalyst exhibited the improved reaction efficiency at both the Langmuir-Hinshelwood and Eley-Rideal pathways. This study provides novel insights on the influence of crystal planes on Fe2O3, which is important for optimizing Fe2O3-based NH3-SCR catalysts.