Steric Hindrance Research Articles

The synergistic anti‐corrosion performance and mechanism of meso‐tetra(4‐carboxyphenyl)porphine on steel bars in alkaline environments

AbstractCorrosion protection of steel bars in alkaline concrete environments poses a common challenge in marine engineering. One approach to mitigate steel bar corrosion is the addition of corrosion inhibitors to the concrete. In alkaline environments, the passivation of rebars occurs through anodic passivation coupled with the cathodic oxygen reduction reaction (ORR). The catalysis of ORR can expedite anode passivation. To investigate the corrosion inhibition of steel bars in alkaline environments, meso‐tetra(4‐carboxyphenyl)porphine (TCPP), known for its ORR catalytic properties, is selected. TCPP forms adsorption films on the surface of steel bars, facilitating the formation of passivation films. TCPP primarily adsorbs onto active sites on the surface of the passivation film, where lattice iron ions have leached. The adsorbed TCPP accelerates the formation of the passivation film through ORR catalysis, inhibiting the development of passivation film defects and enhancing the integrity and protection of the passivation film. The most significant effect is observed when the concentration of TCPP is 0.5 mmol/L. The physical adsorption of TCPP is primarily determined by the negative charge centers, namely the carboxyl group O and the pyrrole N. However, due to steric hindrance caused by the unrestricted rotation of the carboxyl benzene, the pyrrole N does not play a dominant role in chemical adsorption. Instead, the active site for chemical adsorption is the carboxyl group O. The adsorption process significantly reduces the diffusion coefficient of TCPP molecules, providing a robust and stable adsorption binding. Phthalocyanine molecules without carboxyl benzene groups adopt a planar structure, allowing them to form stable adsorption configurations on the iron surface through flat adsorption. This observation provides guidance for the design of novel metal phthalocyanine molecules. Specifically, the development of metal phthalocyanine molecules with modifying groups that are coplanar with the phthalocyanine ring and possess restricted rotation can achieve flat adsorption, improve coverage rate, and enhance adsorption configuration stability.

Effect and mechanism of Mn2+ on urease activity during anaerobic biological treatment of landfill leachate.

As a crucial hydrolytic enzyme, urease plays a vital role in anaerobic biological treatment. It is well-known that manganese ions are abundant in landfill leachate, but their concentration fluctuates significantly. However, few studies have investigated the effect and mechanism of different concentrations of Mn2+ on urease activity during anaerobic biological treatment of landfill leachate. This paper aimed to investigate the effects and mechanisms of different concentrations of Mn2+ on urease activity. The results showed that an appropriate amount of Mn2+ could significantly enhance urease activity, while a high concentration of Mn2+ could inhibit it. Insight into the mechanisms behind this phenomenon, various methods such as Zeta potential, particle size, ultraviolet spectroscopy, fluorescence spectroscopy, Fourier transform infrared spectroscopy, and statistical analysis were employed in our study. Research suggested that, on one hand, Mn2+ may form hydrogen bonds with the side chain amino or carboxyl groups of urease amino acid residues, affecting the structure of urease through hydrogen bonding. Additionally, Mn2+ also binds to urease through hydrophobic interactions. On the other hand, the C-OH and C-N functional groups in urease have a strong affinity for Mn2+, and changes in these functional groups can greatly enhance the activity of urease. Furthermore, under the action of high concentrations of Mn2+, while the structure of urease becomes more stable, there is also a steric hindrance phenomenon that affects the substrate from entering the catalytic center. Therefore, studying the mechanism of Mn2+ affecting urease activity has significant biological significance and provides a new perspective for exploring the impact of metals on anaerobic bioprocessing of landfill leachate.

Structure–property relationships of cationic polyurethane surfactants: Impact on surface activity and anticorrosion performance

Three cationic polyurethane surfactants (LC1–1, LC2–2, and LC2–3), each featuring different hydrophobic structures, were synthesized using isophorone diisocyanate, N-methyl diethanolamine, 1-bromohexadecane, and 1-bromobutane. The synthesized cationic polyurethane surfactants exhibited low surface tension, excellent foaming properties, and resistance to salt, attributed to steric hindrance among long-chain alkyl groups and their “multi-point anchoring” ability. The corrosion inhibition performance of polyurethane surfactants on carbon steel in 1 M HCl solution was evalutated, and LC2–2 showing a considerable corrosion inhibition efficiency of 97.0 %. This film effectively reduced/isolated contact between the corrosive solution and the steel interface. Furthermore, quantum chemical calculations corroborated the electrochemistry experiment results, affirming that the molecular structure of LC2–2 is particularly conducive to inhibiting the corrosion of carbon steel. This study explores the relationship between the molecular structure of surfactants and its impact on both surface activity and corrosion inhibition efficiency.

In vitro and in silico analysis for elucidation of α-amylase and α-glucosidase: Synthesis, structural confirmation and drug likeness of benzothiazole derived thiazole base bis-Schiff base derivatives

In this study, we have synthesized S-substituted benzothiazole derived thiazole bearing bis-Schiff base derivatives (1–19) and characterized via different spectroscopic techniques including NMR and HR-EIMS and then screened against α-amylase and α-glycosidase. All the analogues show excellent inhibitory capability. Analogues 1 (IC50 = 3.18 ± 0.72 µM and 2.30 ± 1.80 µM) and 4 (IC50 = 1.40 ± 0.59 µM and 2.10 ± 0.78 µM) were found to be the strongest among the all in contrast with standard drug acarbose (IC50 = 4.30 ± 0.18 and 6.45 ± 1.84 µM) for α-amylase and α-glycosidase. Some derivatives show good potency against both the enzymes while few were found moderately potent. For all the molecules structure–activity relationship was carried to determine the decrease/increase in potency due to steric hindrance, bulky nature, position, type, size, quantity of the substituent/s on phenyl rings. Molecular docking and ADME analysis were carried out to signify the binding interactions of the most potent derivatives with the active site of enzymes.

Electrophilic aryl spiroannulation induced by diaryliodonium salts： efficient synthesis of [5,5]-spiro lactone-lactam scaffolds from α-cyanocarboxylates

Spirocyclic architectures represent one of the privileged three-dimensional scaffolds in pharmaceutical chemistry and drug discovery, while the new-skeletal synthesis of spiromolecules from simple starting materials remains a challenging task. Here, we report a first diaryliodonium salts mediated electrophilic aryl spiroannulation reaction from simple substrates α-cyanocarboxylate. With this strategy, a broad spectrum of new [5,5] spiro-fused skeletons could be efficiently constructed in one step via Cu-catalyzed cascaded N-arylation-acylation and etheral skeleton rearrangement reaction. The key point of this transformation was the intramolecular electrophilic cyclization due to the nucleophilicity of O-atom and electrophilicity of α-C induced by diaryliodonium salts. With this protocol, the more challenging activation of ether bonds was achieved via diaryliodonium salts-mediated. This method has the major advantages of a broad substrate scope and excellent functional group compatibility. Further synthesis elaboration was performed using substrate with steric hindrance to showcase the versatility of this methodology.

Advanced magnetic adsorbents for enhanced phosphorus and fluoride removal from wastewater: Mechanistic insights and applications

A novel mesoporous magnetic nanoparticle adsorbent, Fe3O4@CSH-AAO, was synthesized using the atomization-precipitation method, effectively removing phosphorus (P) and fluoride (F) from wastewater, particularly from the recirculating water of wet-process phosphoric acid. The adsorbent achieved removal efficiencies of 99.6 % for P and 73.5 % for F under conditions of 20 g/L adsorbent dosage, pH ≈ 4, with initial P and F concentrations at 115 mg/L and 38 mg/L, respectively. Equilibrium adsorption data indicated that the adsorption kinetics followed the pseudo-second-order model for F and the pseudo-first-order model for P. The adsorption isotherms fitted the Langmuir model for P and the Freundlich model for F, with maximum adsorption capacities of 37.86 mg P/g and 6.764 mg F/g at pH 4 and 298 K. The surface properties, functionality, and crystallinity were analyzed using BET, SEM, TEM, XRD, and XRF. Furthermore, XPS analyses and molecular dynamics (MD) simulations elucidated that surface Ca in CSH and the exposed Al atoms on the γ-Al2O3 (110) surface serve as optimal adsorption sites for P and F. The steric hindrance imposed by phosphorus contributes to its preferentially higher adsorption capacity over fluoride. This study not only presents an effective method for the removal of phosphorus and fluoride suitable for practical applications but also provides deep insights into the adsorption mechanism, highlighting the pivotal role of steric hindrance in facilitating ion adsorption.

Photoredox/Cu-Catalyzed Decarboxylative C(sp3)-C(sp3) Coupling to Access C(sp3)-Rich gem-Diborylalkanes.

gem-Diborylalkanes are highly valuable building blocks in organic synthesis and the pharmaceutical chemistry due to their ability to participate in multi-step cross-coupling transformations, allowing for the rapid generation of molecular complexity. While progress has been made in their synthetic metholodology, the construction of β-tertiary and C(sp3)-rich gem-diborylalkanes remains a synthetic challenge due to substrate limitations and steric hindrance issues. An approach is presented that utilizes synergistic photoredox and copper catalysis to achieve efficient C(sp3)-C(sp3) cross-coupling of alkyl N-hydroxyphthalimide esters, which can be easily obtained from alkyl carboxylic acids, with diborylmethyl species, providing a series of C(sp3)-rich gem-diborylalkanes with 1°, 2°, and even 3° β positions. Furthermore, this approach can also be applied to complex medicinal compounds and natural products, offering rapid access to molecular complexity and late-stage functionalization of C(sp3)-rich drug candidates. Mechanistic experiments revealed that diborylmethyl Cu(I) species participated in both the photoredox process and the key C(sp3)-C(sp3) bond-forming step.

Antigen Delivery Controlled by an On-Demand Photorelease.

To eliminate infected and cancerous cells, antigen processing and presentation play a pivotal role through the recognition of antigenic peptides displayed on Major Histocompatibility Complex class I (MHC I) molecules. Here, we developed a photostimulated antigen release system that enables the temporal inception of antigen flux. Simple and effective photocaging of the human immunodeficiency virus (HIV)-Nef73-derived epitope, a representative high-affinity MHC I ligand, was provided by steric hindrance to block the recognition by the transporter associated with antigen processing (TAP) in the peptide loading complex (PLC). In response to light, a heteronomous release of antigens and subsequent translocation in various scenarios is demonstrated, including a TAP-related ATP-binding cassette (ABC) transporter reconstituted in liposomes and the native PLC in the endoplasmic reticulum (ER) membrane of human cells. The photochemically induced 'burst' of antigens opens new opportunities for a mechanistic analysis of the antigen translocation machinery and will help to provide insights into antigen processing pathways via an on-demand, subcellular pulse-chase release of antigens.

Homologous Design and Three-Dimensional Quantitative Structure-Activity Relationship Study of Acaricidal 2,4-Diphenyloxazolines Containing Different Heteroatoms and Alkyl Chains.

In order to speculate the three-dimensional structure of the potential binding pocket of the chitin synthase inhibitor, a series of 2,4-diphenyloxazoline derivatives with different lengths of alkyl chains and heteroatoms were designed and synthesized by a homologous strategy. The bioassay results indicate that both the length of the alkyl chains and the type of substituents can affect the acaricidal activity against mite eggs. Compounds containing chloropropyl, alkoxyalkyl, and para-substituted phenoxyalkyl or phenylthioalkyl groups exhibit good activity, while those containing steric hindrance substituents or carbonyl substituents on the benzene ring exhibit reduced activity. Three-dimensional quantitative structure-activity relationship (3D-QSAR) study showed that there may be a narrow hydrophobic region deep in the pocket, and the steric effect plays a more important role than the electrostatic effect. The current work will provide assistance for future molecular design and target binding research.

Quantum Dot-Fab' Conjugates as Compact Immunolabels for Microtubule Imaging and Cell Classification.

Antibodies and their conjugates of fluorescent labels are widely applied in life sciences research and clinical pathology. Among diverse label types, compact quantum dots (QDs) provide advantages of multispectral multiplexing, bright signals in the deep red and infrared, and low steric hindrance. However, QD-antibody conjugates have random orientation of the antigen-binding domain which may interfere with labeling and are large (20-30 nm) and heterogeneous, which limits penetration into biospecimens. Here, we develop conjugates of compact QDs and Fab' antibody fragments as primary immunolabels. Fab' fragments are conjugated site-specifically through sulfhydryl groups distal to antigen-binding domains, and the multivalent conjugates have small and homogeneous sizes (∼12 nm) near those of full-sized antibodies. Their performance as immunolabels for intracellular antigens is evaluated quantitatively by metrics of microtubule labeling density and connectivity in fixed cells and for cytological identification in fixed brain specimens, comparing results with probes based on spectrally-matched dyes. QD-Fab' conjugates outperformed QD conjugates of full-sized antibodies and could be imaged with bright signals with 1-photon and 2-photon excitation. The results demonstrate a requirement for smaller bioaffinity agents and site-specific orientation for the success of nanomaterial-based labels to enhance penetration in biospecimens and minimize nonspecific staining.

The two-step strategy for enhancing the specific activity and thermostability of alginate lyase AlyG2 with mechanism for improved thermostability

To overcome the trade-off challenge encountered in the engineering of alginate lyase AlyG2 from Seonamhaeicola algicola Gy8T and to expand its potential industrial applications, we devised a two-step strategy encompassing activity enhancement followed by thermal stability engineering. To enhance the specific activity of efficient AlyG2, we strategically substituted residues with bulky steric hindrance proximal to the active pocket with glycine or alanine. This led to the generation of three promising positive mutants, with particular emphasis on the T91S mutant, exhibiting a 1.91-fold specific activity compared to the wild type. To mitigate the poor thermal stability of T91S, mutants with negative ΔΔG values in the thermal flexibility region were screened out. Notably, the S72Ya mutant not only displayed 17.96 % further increase in specific activity but also exhibited improved stability compared to T91S, manifesting as a remarkable 30.97 % increase in relative activity following a 1-hour incubation at 42 °C. Furthermore, enhanced kinetic stability was observed. To gain deeper insights into the mechanism underlying the enhanced thermostability of the S72Ya mutant, we conducted molecular dynamics simulations, principal component analysis (PCA), dynamic cross-correlation map (DCCM), and free energy landscape (FEL) analysis. The results unveiled a reduction in the flexibility of the surface loop, a stronger correlation dynamic and a narrower motion subspace in S72Ya system, along with the formation of more stable hydrogen bonds. Collectively, our findings suggest amino acids substitutions resulting in smaller side chains proximate to the active site can positively impact enzyme activity, while reducing the flexibility of surface loops emerges as a pivotal factor in conferring thermal stability. These insights offer valuable guidance and a framework for the engineering of other enzyme types.

Ring Contraction by Rearrangement of Sterically Congested Cyclic (Amino)(aryl)carbenes.

The rearrangement of sterically congested cyclic (amino)(aryl)carbenes (CAArCs) by the reaction of related iminium salts with potassium bis(trimethylsilyl)amide is reported, allowing for forming benzocyclobutanimines via a ring contraction process. Mechanistic studies by theoretical calculations indicate that the formation of conjugated ketenimines as intermediates could be considered, in which steric hindrance caused by N-alkyl motifs of CAArCs plays an important role in promoting the ring-opening by the cleavage of C-N bond.

Lead sulfide quantum dot-linear low-density polyethylene composites for near-infrared Mini-LEDs

Lead sulfide quantum dots (QDs), presenting near-infrared (NIR) emissions, have gained extensive interest within the realm of NIR light-emitting diodes (LEDs). However, the intricate surface defect passivation poses a major impediment that curbs broader applications of PbS QDs. To address it, we introduce linear low-density polyethylene (LLDPE) as a facilitating agent for the aggregation of PbS QDs, aiming to improve their optical properties by harnessing a stress-inducing effect. Compared to the bare PbS QDs that are luminescence silent, the PbS aggregates formed with the addition of LLDPE show a notable photoluminescence quantum yield (PLQY) as high as 20.7 %. Moreover, the presence of LLDPE mitigates the oxidative degradation of lead ions on the PbS QD surface, thereby enhancing the stability of the PbS QDs through steric hindrance. Near-infrared nini-LEDs are demonstrated by combining the PbS QD/LLDPE composites with blue mini-LED chips, which show an emission maximum of 1517.9 nm, a full width at half maximum (FWHM) of 297.6 nm and an energy conversion efficiency (ECE) of 14.6 %. The proposed method opens up new avenues for enhancing the optical properties of PbS QDs without using traditional passivation procedures.

Crystal Face-Dependent Behavior of Single-Atom Pt: Construct of SA-FLP Dual Active Sites for Efficient NO2 Detection.

The strong potential of platinum single atom(PtSA) in gas sensor technology is primarily attributed to its high atomic economy. Nevertheless, it is imperative to conduct further exploration to understand the impact of PtSAon the active sites. In this study,the evolution of PtSAon (100)CeO2and (111)CeO2 is examined, revealing notable disparities in the position and activity of surface PtSAon different crystal planes.The PtSAin (100)CeO2surfacecan enhancethe stability of Ce3+and construct a frustrated Lewis pair (FLP) to form a double active site by combining the steric hindrance effect of oxygen vacancies, whichincreases the response value from 1.8 to 27 and reducethe response-recovery time from 140-192s to 25-26s toward five ppm NO2at room temperature.Conversely,PtSAtends to bind to terminal oxygen on the surface of (111)CeO2and become an independent reaction site.The response valueofPtSA-(111)CeO2surface onlyincreased from 1.6 to 3.8.This research underscores the correlation between single atoms and crystal plane effects, laying the groundwork for designing and synthesizing ultra-stable and efficient gas sensors.

A coarse-grained Poisson–Nernst–Planck model for polyelectrolyte-modified nanofluidic diodes

Abstract Polyelectrolyte (PE)-modified synthetic nanopores have gained substantial research attention because molecular modification promotes ion gating and rectification. However, theoretical research on PE-modified nanopores is relatively scarce because it is difficult to establish an elaborate model for PEs, and it accordingly causes a trade-off between the computational resources needed and the accuracy. Therefore, an appropriate simulation method for the PE-modified nanopore is in high demand and still an enormous challenge. Herein, we report the simulation result of ion transport through PE-modified nanopores through a coarse-grained Poisson–Nernst–Planck method. By modeling the stuffed PE molecules as PE particles in a well-established continuum model, adequate computational accuracy can be achieved with acceptable computational cost. Based on this model, we study the ion transport in PE-modified nanofluidic diodes and reveal the PE around ion selectivity, which can explain the previous experimental works. Intriguingly, we found that the ion enrichment state in the nanofluidic diode is sensitive to steric hindrance and charge distribution near the heterojunction region. This property is critical for the ion transport behavior in the PE-modified nanofluidic diodes. Based on this property, we predict a heterogeneous structure that can realize the single molecule response to charged analytes. These findings provide insights for understanding the ion transport in PE-modified nanofluidic systems and bring inspiration to the design and optimization of high-performance chemical sensors.

Aqueous Supramolecular Transformations of Motor Bola-Amphiphiles at Multiple Length-Scale.

Molecular motor amphiphiles have already been widely attempted for dynamic nanosystems across multiple length-scale for developments of small functional materials, including controlling macroscopic foam properties, amplifying motion as artificial molecular muscles, and serving as extracellular matrix mimicking cell scaffolds. However, limiting examples of bola-type molecular motor amphiphiles are considered for constructing macroscopic biomaterials. Herein, this work presents the designed two second generation molecular motor amphiphiles, motor bola-amphiphiles (MBAs). Aside from the photoinduced motor rotation of MBAs achieved in both organic and aqueous media, the rate of recovering thermal helix inversion step can be controlled by the rotor part with different steric hindrances. Dynamic assembled structures of MBAs are observed under (cryo)-transmission electron microscopy (TEM). This dynamicity assists MBAs in further assembling as macroscopic soft scaffolds by applying a shear-flow method. Upon photoirradiation, the phototropic bending function of MBA scaffolds is observed, demonstrating the amplification of molecular motion into macroscopic phototropic bending functions at the macroscopic length-scale. Since MBAs are confirmed with low cytotoxicity, human bone marrow-derived mesenchymal stem cells (hBM-MSCs) can grow on the surface of MBA scaffolds. These results clearly demonstrate the concept of designing MBAs for developing photoresponsive dynamic functional materials to create new-generation soft robotic systems and cell-material interfaces.

Transferability of Buckingham Parameters for Short-Range Repulsion between Topological Atoms.

The repulsive part of the Buckingham potential, with parameters A and B, can be used to model deformation energies and steric energies. Both are calculated using the interacting quantum atom energy decomposition scheme where the latter is obtained from the former by a charge-transfer-based energy correction. These energies relate to short-range interactions, specifically the deformation of electron density and steric hindrance, respectively, when topological atoms approach each other. In this work, we calculate and fit the energies of carbonyl carbon, carbonyl oxygen, and, where possible, amine nitrogen atoms to the repulsive part of the Buckingham potential for 26 molecules. We find that while the steric energies of all atom pairs studied display exponential behavior with respect to distance, some deformation energy data do not. The obtained parameters are shown to be transferable by calculating root-mean-square errors of fitted potentials with respect to energy data of the same atom in, as far as possible, all other molecules from our data set. We observed that 36% and 10% of these errors were smaller than 4 kJ mol-1 for steric and deformation energy, respectively. Thus, we find that steric energy parameters are more transferable than deformation energy parameters. Finally, we speculate about the physical meaning of the A and B parameters and the implications of the strong exponential and exponential-linear piecewise relationships that we observe between them.

Enhancing ion separation efficiency: Janus charged nanofiltration membrane fabricated via polyethyleneimine-manipulated interfacial polymerization

This research introduces highly efficient nanofiltration (NF) membranes designed for the effective rejection of both divalent cations and anions, a critical feature for advanced water treatment technologies. We have devised a simple yet adaptable approach for fabricating Janus polyamide (PA) thin-films characterized by dual charges, which exhibit pronounced selectivity towards both mono-/divalent anions and cations. Leveraging a straightforward interfacial polymerization (IP) process, we integrated high molecular weight polyethyleneimine (PEI) within the PA matrix. This strategy ensured the preferential formation of a dense, negatively charged upper layer dominated by piperazine (PIP), while cationic macromolecular PEI facilitated the emergence of a loose and positively charged lower layer, thus giving rise to a distinctively charged and structurally heterogeneous PA thin-film. Furthermore, the strategic inclusion of PEI inhibits the diffusion of the PIP, thereby promoting the development of nano-wrinkled structures. This structural innovation not only enhances pure water permeance (16.0 L m−2 h−1 bar−1) but also optimizes ion selectivity through the coordination of steric hindrance and Donnan effects. Consequently, the Janus charged NF membranes we developed exhibit exceptional selectivity for mono-/divalent ions, particularly demonstrating remarkable ion selectivity for Cl−/SO42− and Li+/Mg2+ of 102 and 24, respectively. Our findings introduce a pioneering avenue for fabricating NF membranes that proficiently separate mono-/divalent ions, promising significant advancements in water treatment and purification endeavors.

Bonding of Lignin and Coniferyl Alcohol by a Redox Shuttle of Low-Molecular-Weight Lignols in Enzymatic Oxidative Dehydrogenative Polymerization.

Lignin is an aromatic polymer that constitutes plant cell walls. The polymerization of lignin proceeds by radical coupling, and this process requires radicalization of the phenolic end of lignin by enzymes. However, due to the steric hindrance between enzymes, lignin, and polysaccharides, the direct oxidation of the phenolic end of lignin by the enzyme would be difficult, and the details of the growth of lignin are still unknown. In this study, enzymatic dehydrogenative polymerization experiments were conducted using coniferyl alcohol (CA) and the deuterium-labeled lignin model compound (D-LM) under a noncontact condition in which horseradish peroxidase cannot directly oxidize D-LM due to separation by a dialysis membrane. Analysis of deuterium-labeled degraded compounds obtained by a combination of methylation and thioacidolysis revealed the formation of the bond between the phenolic end of D-LM and CA, suggesting that membrane-permeable, low-molecular-weight lignols functioned as a redox shuttle mediator.

Flower-like hierarchical TS-1/Al2O3 composite supported NiMo catalysts for efficient hydrodesulfurization of dibenzothiophenes

Flower-like Al2O3 materials were successfully incorporated by TS-1 nanocrystals to synthesize Flower-like TS-1-Al2O3 (FTA) micro-mesoporous composite by a facile nano self-assembly method. FTA supported NiMo bimetallic catalysts (NiMo/FTA) were further constructed and applied to the hydrodesulfurization (HDS) reactions for dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT). FTA composites were constructed from flower-like pore structures stacked with nanosheets, which are conducive to the even load and dispersion of active species and the diffusion of macromolecular sulfur-containing compounds with relatively low resistance. The fabrication of TS-1 nanocrystals effectively enhanced the acidic sites, regulated the metal-support interaction, which could increase the stacking layer of MoS2 slabs, and producing more NiMoS-II type active phase. NiMo/FTA-10 presented the excellent HDS conversion of DBT (99.3 %) and 4,6-DMDBT (93.2 %) at 10 h−1, the highest reaction rate constant (2.6 × 10-7 mol g−1 s−1) and turnover frequency values (6.7 × 10-4 s−1) for 4,6-DMDBT HDS reaction. Compared to the direct desulfurization route (DDS), hydrogenation route (HYD) and isomerization route (ISO) can effectively eliminate the steric hindrance of 4,6-DMDBT, which is more conducive to the HDS reaction.