Bridging Hydroxyl Research Articles

Chitosan-polyethersulfone mixed matrix composite membranes utilizing amine and non-amine hafnium-MOFs for enhanced CO2 separation

Exploring the realm of advanced membranes with customizable separation capabilities holds great promise in CO2 separation. A particularly exciting path is the utilization of mixed matrix membranes (MMMs) to surpass the performance of commonly used polymeric membranes. In recent times, there has been a surge of interest in hafnium (Hf) metal–organic frameworks (MOFs) due to their multiple potential sites for CO2 adsorption. These MOFs feature four bridging hydroxyl groups (μ3-OH) positioned at the corners of the tetrahedral cavity, electronegative linker moieties, and Bronsted acid sites arising from undercoordinated metals. In this study, we synthesized task-specific UiO-66(Hf) and UiO-66-NH2(Hf) MOFs and integrated them into a chitosan (CS) matrix to explore their effects on CO2 separation performance of MMMs. Comprehensive analyses using various analytical techniques were conducted on synthesized MOFs and MMMs. At an optimal loading of 5 wt% of UiO-66-NH2(Hf) under humid conditions, the MMMs demonstrated a remarkable 408 % increment in CO2 permeance and a 113 % improvement in CO2/N2 selectivity compared to unfilled CS membranes. Notably, the UiO-66-NH2(Hf) MOF, enriched with amino ligands, exhibited superior dispersibility and enhanced CO2 separation ability compared to the UiO-66(Hf) MOF within the CS matrix. These findings not only approach the 2008 Robeson upper bound curve but also demonstrate consistency in the CO2 separation performance for over 120 hours of exposure at elevated temperatures (85°C) and a feed pressure of 2.21 bar under humid conditions. These challenging conditions, mirroring real-world applications, highlight the stability of the synthesized MMMs as efficient gas separation technologies.

Deep purification of perfluorinated electronic specialty gas with a scalable metal–organic framework featuring tailored positive potential traps

The sequestration of trace hexafluoropropylene (C3F6) is a critical yet formidable task in the production of high-purity perfluoropropane (C3F8), an important perfluorinated electronic specialty gas (F-gas) in the advanced electronics industry. Traditional adsorbents struggle with uneven, low-pressure uptake and compromises in selectivity. This work utilizes aperture size-electrostatic potential matching within a robust metal–organic framework (Al-PMA) to facilitate selective, reversible binding of C3F6 while excluding larger C3F8 molecules. The presence of bridging hydroxyl groups (μ2-OH) in Al-PMA creates positive electrostatic potential traps that securely anchor C3F6 through strong hydrogen bonding, evidenced by in-situ infrared and 19F magic angle spinning nuclear magnetic resonance spectroscopy. Breakthrough experiments demonstrate the efficient removal of trace C3F6 from C3F8 under ambient conditions, achieving C3F8 purity exceeding 99.999%. The scalability of Al-PMA synthesis, remarkable stability, and exceptional performance highlight its potential as a promising adsorbent for industrial C3F6/C3F8 separations.

Revealing the Bro̷nsted Acidic Nature of Penta-Coordinated Aluminum Species in Dealuminated Zeolite Y with Solid-State NMR Spectroscopy.

The inevitable dealumination process of zeolite Y is closely related to ultrastabilization, enhanced Bro̷nsted acidity, and deactivation throughout its life cycle, producing complex aluminum and acidic hydroxyl species. Most investigations on dehydrated zeolites have focused on the Bro̷nsted acidity of tetra-coordinated Al (Al(IV)) and Lewis acidity associated with tricoordinated Al (Al(III)) sites, which has left the penta-coordinated Al (Al(V)) in dealuminated zeolites scarcely discussed. This is largely due to the oversimplified view of detectable Al(V) as an exclusively extra-framework species with Lewis acidity. Here we report the formation of Bro̷nsted acidic penta-coordinated Al species (Al(V)-BAS) in the dealumination process. Two-dimensional (2D) through-bond and multiquantum 1H-{27Al} correlation solid-state NMR experiments demonstrate the presence of a bridging Si-OH-Al(V) structure in dealuminated Y zeolites. Different from the conventional belief that water attack leads to the breaking of zeolite framework Al-O bonds in the initial stage of zeolite dealumination, the observed Al(V) as a dealumination intermediate is directly correlated with a BAS pair because of the direct dissociation of water on the framework tetrahedral aluminum (Al(IV)), thus bypassing the cleavage of Al-O bonds. 1H double-quantum solid-state NMR experiments and theoretical calculations provide further evidence for this mechanism, whereas pyridine adsorption experiments confirm stronger acidity of Al(V)-BASs than the traditional bridging hydroxyl groups associated with Al(IV). We were also able to detect the Al(V)-BAS site from dealuminated SSZ-13 zeolite with CHA topology, suggesting that its creation is not specific to the framework structure of zeolites.

Understanding the Impact of Hydroxyls on Synthesizing the Bimetallic Alloy Pt3Co on Al2O3 for CO-PROX

The anchoring effect between surface hydroxyls (–OH) and metal species has been extensively utilized to enhance catalyst stability. Nevertheless, few studies have investigated the impact of alloying process involving different types of –OH species. In this research, we discovered that the formation of the alloy particles Pt3Co was significantly influenced by the presence of distinct –OH species on Al2O3. Intriguingly, those Pt3Co alloy particles exclusively formed on α-Al2O3 owing to the weak interaction between both Pt and Co species and the triply bridging hydroxyls (µ3-OH). In contrast, Pt and Co species were found to be separately dispersed on γ-Al2O3 because of the strong anchoring effect of terminal hydroxyls (µ1-OH), especially for Co atoms. Density functional theory (DFT) calculations highlighted the difference in adsorption energies of the two metals on different hydroxyl groups, providing a theoretical rationale for the influence of hydroxyl groups on alloy formation. The presence of Pt3Co alloy resulted in a fourfold increase in the specific catalytic rate of Pt3Co/α-Al2O3 in CO-PROX compared to Pt3Co/γ-Al2O3. Arguably for the first time, this study demonstrates the association between alloy formation and –OH groups, providing a unique perspective on the design of alloy catalysts.

Uncovering the roles of Ce and Mn for NH3-SCR over Mn-Ce/IM-5 with extraordinarily superior wide-temperature performance

The development of wide-temperature catalyst with glorious activity and the resistance of SO2 for NH3-SCR reaction are of great importance. However, the preparation of wide-temperature catalyst with outstanding NH3-SCR performance and the resistance of SO2 is still challenging. In this work, Mn and Ce modified IM-5 molecular sieve catalyst (MC-5) was synthesized by incipient wetness impregnation method and the relationship of structure-activity was studied. MC-5 exhibited superior NOx conversion and it was more than 87% in the temperature range of 150-500 °C and ca. 100% at 225 °C due to the high concentration of Mn4+ and chemisorbed oxygen, the excellent redox ability and the synergistic effect of Mn and Ce. Meanwhile, the redox cycle of Mn4++Ce3+↔Mn3++Ce4+ promoted the electron transfer. 27Al NMR spectra and NH3-TPD confirmed Mn ion was mainly located on the bridge hydroxyl group (Brønsted acid sites). The localization energies ΔE of (Al, Mn) for IM-5 was determined by theoretical calculation and the reaction mechanism of M-5 catalyst on Brønsted acid sites was proposed. The reaction mechanism of M-5 catalyst on Brønsted acid sites followed L-H mechanism. And interestingly enough, the NH3-SCR activity of MC-5 significantly increased in the presence of SO2 at 200 °C. One of the reasons was that Ce binded more easily to SO42- and thus protected the active site Mn from sulfation. The other reason was the generation of more acid sites.

Scanning Tunneling Microscopy Visualization of Polaron Charge Trapping by Hydroxyls on TiO2(110).

Using scanning tunneling microscopy (STM), we investigate the spatial distribution of the bridging hydroxyl (OHb) bound excess electrons on the rutile TiO2(110) surface and its temperature dependence. By performing simultaneously recorded empty and filled state imaging on single OHbs at different temperatures in STM, we determine that the spatial distribution of the OHb bound excess electrons retains a symmetric four-lobe structure around the OHb at both 78 and 7 K. This indicates that OHbs are much weaker charge traps compared to bridging O vacancies (Ob-vac). In addition, by sequentially removing the capping H of each OHb using voltage pulses, we find that the annihilation of each OHb is accompanied by the disappearance of some lobes in the filled state STM, thus verifying the direct correlation between OHbs and their excess electrons.

Effect of arsenate and phosphate substitution on hydroxyl group in libethenite Cu2PO4OH - olivenite Cu2AsO4OH solid solution series

Libethenite and olivenite have been regarded as intriguing photocatalysts because of their singular structures. Copper hydroxy-phosphates and -arsenates exhibit distinctive properties: they incorporate bridging hydroxyl (OH) groups shared by neighboring copper atoms. In materials employed for photoelectrochemical applications, the significance of surface OH groups and OH-related defects frequently varies and is contingent upon the specific material system and the reaction under consideration. Hydroxyl groups can enhance photocatalytic performance by generating OH radicals or serving as crucial agents in catalytic reactions. Therefore, the presence of an OH group within the crystal structure of the material can give rise to potentially interesting behaviors. Seven compounds within the solid solution series of libethenite Cu2PO4OH and olivenite Cu2AsO4OH with stoichiometric ratio (Cu2(Px,As1- xO4)OH, x = 0, 0.1, 0.3, 0.5, 0.7, 0.9, 1 were synthesized at 70 °C via aqueous solutions, and their properties were examined using X-ray diffraction (XRD), Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopy. The effect of substituting (PO4)3– ions with (AsO4)3– ions on the alteration of the lattice parameters and spectral characteristics was elucidated by analyzing the correlation between the chemical composition and X-Ray diffraction peak positions. The substitution process leads to modifications in the unit cell parameters and volume. These isomorphic substitutions can be also discerned through alterations in the infrared and Raman spectra, which exhibit variations in the position and intensity of the bands corresponding to phosphates, arsenates, and hydroxyl ions. The incorporation of As into the solid solution resulted in altered bond lengths and geometries, which is consistent with the symmetry transition from orthorhombic libethenite to monoclinic olivenite. The variations in the unit cell parameters and the shifts in the peak position exhibited non-linear trends, and a discernible step was observed between the Cu2(P0·3As0.7)O4OH and Cu2(P0·5As0.5)O4OH intermediate phases. The findings of this study will prove beneficial in evaluating the feasibility of the libethenite-olivenite isometric series as a photocatalysts.

2,2′‐Thienoviologens with Low Reduction Potential for Electrochromism and Visible‐Light‐Driven Hydrogen Evolution Using g‐C3N4‐Based Composites via Hydrogen Bonds

AbstractA series of sulfur‐bridged 2,2′‐viologens, 2,2′‐thienoviologens (2,2′‐SV2+) with propyl bridge and hydroxyl bridges, are synthesized for the first time. The 2,2′‐thienoviologens exhibited improved visible‐light absorption, narrow energy gap, more negative reduction potential (160 mV lower than 4,4′‐thienoviologens) and more stable free radical states compared with 4,4′‐thienoviologens and parent 2,2′‐viologens. The utilization of femtosecond transient absorption (fs‐TA) demonstrated that 2,2′‐thienoviologen can produce distinct charge‐separated states under visible light excitation. Due to their excellent photophysical and electrochemical properties, the 2,2′‐thienoviologens are used for electrochromic devices and combined with g‐C3N4 via hydrogen bonds for visible‐light catalytic production. Based on the advantageous electron‐donating properties of 2,2′‐SV2+, the hydrogen release efficiency of the 2,2′‐thienoviologens‐modified composites is 8542 µmol·h−1·g−1, a value that is the highest reported for hydrogen production from organic small‐molecule‐modified g‐C3N4 and 78 times higher than that of unmodified g‐C3N4. This study presents a concise method to convert solar energy and broaden the potential applications of 2,2′‐viologens in photocatalytic systems.

Evolution of Ce4+ Lewis acidity during dehydroxylation of ceria nanoparticles with different morphology: An integrated FTIR, DFT and HRTEM study

Ceria is an important redox catalyst and its activity depends on the open Ce4+/Ce3+ sites, anion vacancies, surface OH groups and the ratio between them. We investigated the effect of dehydroxylation on the evolution of Ce4+ Lewis acidity of oxidized ceria nanocubes, nanopolyhedra, and nanorods. The {111} face is not hydroxylated and the exposed Ce4+ sites, after dehydration, adsorb CO weakly, forming linear carbonyls. The hydroxyl coverage of the {110} face consists of terminal and bridging hydroxyls, and dehydroxylation occurs between 423 and to 573 K by interaction between these groups. The produced Ce4+ sites form stronger linear carbonyls. The {100} face is covered by bridging OH groups, which are progressively removed even at 773 K. The created Ce4+ sites coordinate CO in a bridging mode and, at higher coverage, connect two bridging CO molecules. Ce4+ sites on edges and defects appear at high evacuation temperature and form mono- and dicarbonyls.

Efficient Homolytic Cleavage of H2O2 on Hydroxyl-Enriched Spinel CuFe2O4 with Dual Lewis Acid Sites.

Traditional H2O2 cleavage mediated by macroscopic electron transfer (MET) not only has low utilization of H2O2, but also sacrifices the stability of catalysts. We present a non-redox hydroxyl-enriched spinel (CuFe2O4) catalyst with dual Lewis acid sites to realize the homolytic cleavage of H2O2. The results of systematic experiments, in situ characterizations, and theoretical calculations confirm that tetrahedral Cu sites with optimal Lewis acidity and strong electron delocalization can synergistically elongate the O-O bonds (1.47 Å → 1.87 Å) in collaboration with adjacent bridging hydroxyl (another Lewis acid site). As a result, the free energy of H2O2 homolytic cleavage is decreased (1.28 eV → 0.98 eV). H2O2 can be efficiently split into ⋅OH induced by hydroxyl-enriched CuFe2O4 without MET, which greatly improves the catalyst stability and the H2O2 utilization (65.2 %, nearly 2 times than traditional catalysts). The system assembled with hydroxyl-enriched CuFe2O4 and H2O2 affords exceptional performance for organic pollutant elimination. The scale-up experiment using a continuous flow reactor realizes long-term stability (up to 600 mL), confirming the tremendous potential of hydroxyl-enriched CuFe2O4 for practical applications.

Efficient Homolytic Cleavage of H2O2 on Hydroxyl‐Enriched Spinel CuFe2O4 with Dual Lewis Acid Sites

AbstractTraditional H2O2 cleavage mediated by macroscopic electron transfer (MET) not only has low utilization of H2O2, but also sacrifices the stability of catalysts. We present a non‐redox hydroxyl‐enriched spinel (CuFe2O4) catalyst with dual Lewis acid sites to realize the homolytic cleavage of H2O2. The results of systematic experiments, in situ characterizations, and theoretical calculations confirm that tetrahedral Cu sites with optimal Lewis acidity and strong electron delocalization can synergistically elongate the O−O bonds (1.47 Å → 1.87 Å) in collaboration with adjacent bridging hydroxyl (another Lewis acid site). As a result, the free energy of H2O2 homolytic cleavage is decreased (1.28 eV → 0.98 eV). H2O2 can be efficiently split into ⋅OH induced by hydroxyl‐enriched CuFe2O4 without MET, which greatly improves the catalyst stability and the H2O2 utilization (65.2 %, nearly 2 times than traditional catalysts). The system assembled with hydroxyl‐enriched CuFe2O4 and H2O2 affords exceptional performance for organic pollutant elimination. The scale‐up experiment using a continuous flow reactor realizes long‐term stability (up to 600 mL), confirming the tremendous potential of hydroxyl‐enriched CuFe2O4 for practical applications.

Acidity of Isomorphic Substituted Zeolites with B, Al and Ga Revisited.

Isomorphic substitution of zeolites with B, Al and Ga is a widely used approach in catalysis. The experimentally reported trend of their acidities decreases in the order: Al>Ga>B. However, a consistent explanation is still lacking in the literature. To bring more understanding of this trend, density functional theory computations were conducted on several model systems. First, the acidity of small clusters with two (2T) and five (5T) tetrahedral sites was analyzed. These systems were then projected onto three large void structures: H-[A]-BEA (52T), H-[A]-FAU (84T) and H-[A]-MOR (112T) with A=B, Al, Ga. Our electron density and Interacting Quantum Atom analyses show that the acidity of Al zeolites originates from the much stronger O-Al bond, which is dominated by the electrostatic attraction. The bridging hydroxyl therefore donates more charge density to the metal, the proton becomes more positive and consequently more acidic. Ga zeolites are more acidic than B zeolites due to the greater covalent nature on the O-Ga bond. The resulting acidity, as seen by ammonia, depends on both the acidic oxygen and the charge distribution of the surrounding oxygens exerted by the substituents.

Desulfurization performance and mechanism for H2S from blast furnace gas over FAU zeolite sorbent

The desulfurization of blast furnace gas is crucial to meet the strict requirements for clean production of steel industry. However, the composition of blast furnace gas is complicated, and the gases of H2O, CO, CO2, and O2 would significantly affect the desulfurization activity. Therefore, the desulfurization performance for H2S in simulated blast furnace gas by Na-type FAU zeolites with different Si/Al was investigated. The physicochemical properties of zeolite sorbents were measured, and their correlation with desulfurization performance was studied. Moreover, the adsorption mechanism of H2S was investigated. The breakthrough sulfur capacity improved with the increase of relative crystallinity, Na+ content, specific surface area, and the decrease of Si/Al ratio. The adsorption mechanism of H2S on Na-type FAU zeolite was proposed. One is the hydrogen bond interaction between the bridging hydroxyl groups and H2S, and the other one is the base-acid interaction between sodium ion and H2S. In blast furnace gas, when interacting with Na+, H2S would be transformed into S, which further oxidized into thiosulfate and sulfate by O2.

Bridging and terminal hydroxyl groups of Zr(OH)4 as active sites for the ultraselective transformation of biomass-based alcohols

Developing a cost-effective and multi-functional heterogeneous catalyst for various biomass transformations is important in both academic and industrial communities.

Double self-reinforced coordination modulation constructing stable Ni4+ for water oxidation

Nitrate ligands and Co atoms not only promote the formation of Ni4+ by accelerating deprotonation and attracting electrons, but also adsorb the electron-withdrawing bridge hydroxyl to stabilize Ni4+.

In English

Molecular models for tin dioxide nanoparticles containing 1-7 metal atoms and coordinated or constitutive water have been constructed. Dependent on the composition of the models, the coordination number of the tin atom varied from 4 to 6, and that of oxygen was 2 or 3. The considered models contained both terminal (Sn–OH) and bridging (Sn–OH–Sn) hydroxyl groups, and also bridging (Sn–O–Sn) groups. Their equilibrium spatial and electronic structures were calculated using the second-order Møller-Plesset perturbation theory method with the SBKJC valence-only basis set. To assess the gas-phase acidity of the dioxide surface, the deprotonation energy of the studied models was determined. The adsorption energy of water molecules and hydroxide ions on aprotic (incompletely coordinated) tin atoms, which act as Lewis acid centers, was calculated. In order to estimate the pKa value of the surface of tin dioxide, the Gibbs free energy was calculated for the process of formation of ion pairs due to the proton transfer from hydroxyl groups to adsorbed water molecules. Based on the analysis of the energy effects of the coordination of water molecules and of hydroxide ion, the removal of a proton and its transfer on the hydrated surface of tin dioxide, quantitative estimates have been made of the acid-base characteristics of the active sites of the SnO2 surface. The dependence of the acidity of hydroxyl groups and coordinated water molecules on the coordination number of the oxygen atom and the neighboring tin atom, as well as on the dimensions of the cluster model, was revealed. It is shown that the acidity of protonic and aprotic sites naturally decreases with an increase in the coordination number of the tin atom. The method of calculating the value of pKa used in the work for the smallest model of the SnO2×2H2O composition allows one to reproduce the experimental data for stannic acids.

Impact of Calcination Temperature on Tungsten‐based Composite Catalysts for Olefins Metathesis

AbstractThe thermal treatment is one of the key procedures for the distribution and transformation of active sites for the supported metal oxide catalysts. However, the underlying impacts of thermal treatment on composite supported catalysts receives limited attention due to the additional complexity of the composite support. In this work, the progressive gradient in the metathesis activity, as the function of enhanced calcination temperature, has been observed for the tungsten‐based catalysts supported on the hierarchical ZSM‐5 zeolite‐alumina composite. The metathesis activity, reflected by ethene conversion, undergoes a stepwise growth from 24.2 % to 38.9 % along with the enhanced calcination temperature from 723 K to 923 K. The supported W‐oxo species share high similarity in structural states except their interaction with the Brønsted acidic bridge hydroxyl groups in zeolite. The density of bridge hydroxyl groups is reduced as the function of enhanced calcination temperatures, which reflects the intensified anchoring of surface W‐oxo species. It should be noted that such dependence is not observed for their counterparts based on microporous ZSM‐5 zeolite‐alumina. These sharp comparisons highlight the critical routes of thermal migration of W‐oxo species along the intrazeolite‐alumina interface in the evolution of active sites for the olefins cross‐metathesis reaction.

Breaking the Trade-Off Between Polymer Dielectric Constant and Loss via Aluminum Oxo Macrocycle Dopants for High-Performance Neuromorphic Electronics.

The dielectric layer is crucial in regulating the overall performance of field-effect transistors (FETs), the key component in central processing units, sensors, and displays. Despite considerable efforts being devoted to developing high-permittivity (k) dielectrics, limited progress is made due to the inherent trade-off between dielectric constant and loss. Here, a solution is presented by designing a monodispersed disk-shaped Ce-Al-O-macrocycle as a dopant in polymer dielectrics. The molecule features a central Ce(III) core connected with eight Al atoms through sixteen bridging hydroxyls and eight 3-aminophenyl peripheries. The incorporation of this macrocycle in polymer dielectrics results in an up to sevenfold increase in dielectric constants and up to 89% reduction in dielectric loss at low frequencies. Moreover, the leakage-current densities decrease, and the breakdown strengths are improved by 63%. Relying on the above merits, FETs bearing cluster-doped polymer dielectrics give near three-orders source-drain current increments while maintaining low-level leakage/off currents, resulting in much higher charge-carrier mobilities (up to 2.45cm2 V-1 s-1 ) and on/off ratios. This cluster-doping strategy is generalizable and shows great promise for ultralow-power photoelectric synapses and neuromorphic retinas. This work successfully breaks the trade-off between dielectric constant and loss and offers a unique design for polymer composite dielectrics.

Research on Calcium Chloride Weighted Polymer Fracturing Fluid for Ultra Deep and High Stress Reservoirs

To enhance fracture and conversion effects in deep and ultra-deep oil and gas reservoirs, a low-cost polymer-weighted fracturing fluid technique was developed using industrial calcium chloride as a weighting agent and synthesizing a polyacrylamide polymer, FA-31, with a molecular weight of 4-6 million, as a thickening agent. In addition, we have developed an amphoteric metal crosslinker capable of forming multiple hydroxyl bridges with crosslinked groups, a novel XG160 high-efficiency gel breaker, and a complete set of stress corrosion inhibitors. The optimal concentration for the use of calcium chloride dihydrate is 46% and the density of aqueous solution is 1.35 g/cm3. The developed highly salt-resistant polymer dissolves rapidly in a high-density calcium chloride salt solution. The industrial calcium chloride gel formed by polymer has a maximum temperature resistance of 170 °C, a shear rate of 170 s-1 for 120 min, and a viscosity of more than 100 mPa·s. It also performs well in high-temperature suspension sand conditions. The viscosity of the gel breaker is less than 5 mPa·s. Laboratory tests have shown a core damage rate of about 20% and no stress corrosion cracking. The on-site application of liquid preparation and construction has been smooth, achieving the desired effect of reducing construction pressure. For example, when refurbishing a 7500 m reservoir, the building pressure can be reduced by 10-20 MPa. On-site testing of calcium chloride-weighted frac fluids has confirmed their effectiveness as a cost-effective alternative to conventional weighted frac fluids, providing a viable solution for the conversion of deep, ultra-deep, high-stress oil and gas reservoirs.

The effect of hydroxyl and metal synergetic structures on the FCC diesel hydrotreating performance of NiMo/Al2O3 catalysts

Two NiMo/Al2O3 catalysts were prepared using impregnation solutions with different acid-base properties. And the effects of the surface structural differences on FCC diesel hydrotreating and desulfurization performance were investigated. XRD, Raman, H2-TPR, TEM, XPS characterization showed that NiMoO4 and polymolybdates, the mainly metal phase on the surface of NiMo/Al2O3-A, would tend to form a three bridging hydroxyl structure with the γ-Al2O3 support. The abundant NiMo alloy structures weakened the interaction between metal and oxygen atoms. While the NiMo/Al2O3-B with more developed specific surface area, pore volume and acid content tended to form double bridging hydroxyl structures, which had more active interactions with metals. The higher sulfidation degree of NiMo/Al2O3-B could be observed, exhibiting more NiMoS structures and stronger metal synergetic effects. The performance evaluation results showed that NiMo/Al2O3-A had better desulfurization and denitrification performance, and the content of S and N in the diesel decreased to 211 μg/g and 96.3 μg/g, respectively, which was attributed to the more active phases brought about by the good MoS2 dispersion. On the other hand, NiMo/Al2O3-B exhibited better hydrotreating performance, with the content of alkanes and monocyclic aromatic hydrocarbons in the product increasing from 20.5% and 24.2% to 33.6% and 48.7%, respectively. The higher content of alkanes and monocyclic aromatic hydrocarbons provided a wider range of application for FCC diesel after upgrading.