JOURNAL OF CATALYSIS
·
2024
·
IF 6.5
Yin Che,Xuezhen Liu,Lifei Liu,Yali Du,Xia An,Xu Wu
Arranging an ammonia oxidation process after the selective catalytic reduction of NO x by NH 3 (NH 3 -SCR) system is an effective way for ensuring the DeNO x efficiency and controlling the slip ammonia. To improve operability and reduce operating costs in ammonia selective catalytic oxidation (NH 3 -SCO), developing feasible and efficient catalysts becomes meaningful. Herein, focusing on the dilemma of Ag/Al 2 O 3 catalysts in NH 3 -SCO applications, Ag/MgAlO x catalysts with different support different crystalline phase structures (5 %Ag/MgAl-LDO and 5 %Ag/MgAl 2 O 4 ) were innovatively synthesized and systematically evaluated application potential in NH 3 -SCO. Results indicated that the introduction of Mg apparently broadened reaction temperature window and catalytic performance of 5 %Ag/MgAl 2 O 4 was higher than 5 %Ag/MgAl-LDO, while the N 2 selectivity was completely opposite. The combination of series characterization and density functional theory (DFT) calculations revealed that 5 %Ag/MgAl 2 O 4 surface has more Ag 0 species with small particle size, which is favorable for ammonia adsorption and activated dehydrogenation to further promote reaction of NO x species, resulting in a higher NH 3 -SCO activity. In contrast, 5 %Ag/MgAl-LDO readily induces oxidized Ag species and Ag 0 is more inclined to be present in large particle sizes, which is more conducive to dissociation of O 2 to produce reactive O species (O*) leading to the peroxidation of ammonia to nitrate and thus, positively affects the improvement of N 2 selectivity. Model catalyst 5 %Ag/MgAl-650 (mixed-phase) was prepared by controlling the roasting conditions and exhibited excellent catalytic performance in NH 3 -SCO with almost 93 % of NH 3 oxidized at 250 °C (N 2 selectivity up to 71 %). This work could afford theoretical support for the optimization and application of catalysts with high performance at low temperatures in selective catalytic oxidation of slip ammonia.
研究领域:
环境科学
·
催化材料
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2019
·Vol. 7
·期 36
·20878-20890
·
IF 10.733
Aolei Gao,Xinjuan Hou,Zhenhua Sun,Shaopeng Li,Huiquan Li,Jianbo Zhang
Spinel-type lithium manganese oxides (LMOs) are the most promising lithium-adsorption materials. LMOs can be in the form of solid solutions of LiMn2O4, Li1.33Mn1.67O4, and Li1.6Mn1.6O4. However, uncertainty about the lithium-desorption mechanism restricts material development. The synthesis of intermediate products of spinel-type LMOs during acid treatment is important to investigate such a mechanism. In this work, precisely controlled acid treatment experiments were performed to successfully obtain the intermediate products of LiMn2O4, Li1.33Mn1.67O4, and Li1.6Mn1.6O4. For LiMn2O4, lithium was desorbed with the dissolution of manganese. For Li1.33Mn1.67O4 and Li1.6Mn1.6O4, the lithium-desorption mechanism was an ion-exchange reaction, where lithium ions (Li+) in the 8a sites were prioritized for the ion-exchange reaction compared with Li+ in the 16d sites. Density functional theory (DFT) calculation results confirmed the experimental results and explained that the prioritization of Li+ in the 8a sites arose from its lower reaction-energy barrier, thereby revealing that Li+ preferred to move to the nearest vacant 8a sites when lithium was desorbed because of the lower diffusion-energy barrier. This work is the first to clarify the lithium-desorption mechanism through experiments and DFT calculations, and thus lays a foundation for the further exploitation of LMOs.
研究领域:
材料科学
·
电化学
·
计算化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2025
·
IF 8.3
Yangbo Ma,Miao Fa,Yihui Zhang,Liuying Xiong,Xiying Li,Shuaishuai Zhou,Wei Chen,Liqun Mao
Precious metals loading strategy is an effective method to increase the reactivity of CdS based photocatalysts for hydrogen evolution from water splitting under visible light. The key problem of such strategy is the affecting mechanism, which determined by the composition, species and structure of the loaded metals. In this study, AgPd bimetallic nanoclusters (Ag x Pd y ) were prepared and then loaded onto the surface of snowflake-like CdS and the affecting mechanism was qualitatively and quantatively investigated through both instrumental analysis and computational method. The composition and structure of synthesized samples were examined through XRD, TEM, and XPS, by which the successful synthesis of AgPd bimetallic nanocluster alloys with an average particle size of approximately 3 nm were confirmed. Further, the hydrogen evolution performance of Ag x Pd y /CdS was tested under visible light and the prepared AgPd 3 /CdS achieved a hydrogen evolution rate of 73.93 mmol h −1 g −1 , which is a 28 % improvement over Pd/CdS and a 381 % improvement over CdS, with an AQY of 44.68 % at 420 nm. The photoelectrochemical tests (LSV, I-T, EIS, PL, and TR-PL), ESR, and TRPL were applied to qualitatively demonstrate the function of Ag x Pd y nano-cocatalyst, and the testing results indicated that the cocatalyst significantly enhances the separation and transfer efficiency of photoinduced electrons, while further lowering the hydrogen evolution reaction energy barrier. Based on that, affecting mechanism was further determined through DFT simulation quantitatively. The prediction results indicated that the unique nanoclusters structure of AgPd 3 contribute with the high work function and low d band center position increase the transfer efficiency of the photoinduced charge carriers. This study quantitatively revealed the relationship among compostion, structure and reactivity of the photocatalysts, provided an method to investigate the affecting mechanism of bimetallic hydrogen evolution photocatalysts and contributed to the advancement of renewable energy development.
研究领域:
材料科学
·
可再生能源
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
ChemSusChem
·
2024
·
IF 7.5
Xingyu Luo,Cheng Xie,Zhefei Zhao,Meiqin Shi,Huajun Zheng
Graphical Volcano plots are highly effective for understanding catalyst mechanisms and rational designing high-performance catalysts, particularly across different metals. However, the understanding of the relationship between different metals and their reaction mechanisms in 5-Hydroxymethylfurfural (HMF) reduction reactions is still limited. In this study, we explore the Gibbs free diagram of HMF reduction reactions on different metal surfaces and construct a volcano plot that connects HMF adsorption energy with the energy barriers of the rate-determining step. This provides a deeper understanding of HMFRR. Our theoretical findings align well with experimental results. Furthermore, we selectively constructed an AgPb bimetal interface based on our volcano plot, which boosted the catalyst activity. DFT calculations revealed that the AgPb bimetal surface effectively adjusts HMF adsorption energy and reduces energy barriers, suggesting that rational designing bimetal catalysts based on volcano plots is efficient. 2,5-bis(hydroxymethyl)furan (BHMF) derived from 5-Hydroxymethylfurfural (HMF) through a hydrogenation process has extensive applications in the production of resins, polymers, and artificial fibers. However, screening out the candidate and then modulating the active site to optimize the catalyst for high yield of BHMF are currently insufficient. In this study, Gibbs free energy diagrams of the reduction of HMF on 13 metals were presented, along with the identification of the rate-determining step (RDS) with the highest reaction barrier for each metal. We attempted to construct a volcano plot for HMFRR reaction. Additionally, a strategy was proposed to adjust the reaction barriers of RDS by combining two appropriate metals. Further experiments confirmed that Pb with the lowest energy barrier exhibited the highest HMF conversion (BHMF selectivity) among single metals. The modified catalyst by doping Ag on Pb, further boosted the HMF conversion (BHMF selectivity) from 42.1 % (59.4 %) to 80.8 % (80.9 %), respectively. These results provide an approach to rationally design and construct the catalyst system for efficient conversion of HMF.
研究领域:
催化化学
·
材料科学
·
理论计算
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Water Process Engineering
·
2024
·
IF 6.3
Xiaoqing Wang,Cong Du,Yue Yu,Weiyi Li,Tuo Li,Siyuan Wang,Shanjun Mao,Yongjiang Wang,Junzi Zhao,Chunhua Xiong
Given the crucial impact of lattice matching on the charge-transfer efficiency and overall catalytic activity in heterojunctions, we pre-designed an α-Bi 2 O 3 /Co 3 O 4 photocatalytic system with high lattice matching to reduce dangling bonds and lattice mismatches in heterojunctions (A-axis: 2.77 %, B-axis: 0.86 %). The α-Bi 2 O 3 /Co 3 O 4 heterojunction was synthesized using a coprecipitation strategy and showed a wide optical absorption range, with enhanced absorption beyond 420 nm, and ideal photoelectrochemical responses (the highest current intensity: 0.26 μA (cm 2 ) −1 ). Under simulated sunlight irradiation, the heterojunction removed 97.30 % and 85.32 % of methylene blue and tetracycline, respectively, within 120 min. The degradation was corroborated by total organic carbon removal efficiencies, with methylene blue achieving 92.51 % and tetracycline 87.33 % within 120 min, indicative of the effective mineralization process. Our density functional theory calculations indicated that α-Bi 2 O 3 and Co 3 O 4 generated an internal electric field during the Fermi equilibrium process, which caused the conduction band electrons of α-Bi 2 O 3 to flow towards the valence band of Co 3 O 4 , forming a Z-scheme electron flow. Electrons and holes could be separated and transported in heterojunctions with low interface resistance and then react with dissolved oxygen to generate highly active OH and O 2 − radicals, which induced the efficient degradation of organic pollutants. We explored the key influence of structure on catalytic activity on lattice matching and analyzed the catalytic mechanism of α-Bi 2 O 3 /Co 3 O 4 heterojunctions in terms of charge properties. Our findings should serve as a crucial reference for developing excellent structured photocatalytic materials.
研究领域:
材料科学
·
环境科学
·
计算化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2022
·
IF 5.907
Fayang Guo,Dabao Li,Jeremy B. Fein,Jingcheng Xu,Yingwei Wang,Qiaoyun Huang,Xingmin Rong
Reactions occurring at silicate minerals play a significant role in controlling phenolic endocrine disrupting chemicals' bioavailability and mobility. However, the underlying molecular mechanisms for BPA (bisphenol A) and BPS (bisphenol S) onto montmorillonite (MMT) remain poorly understood. To decipher the molecular-level interfacial configuration and dominant reaction mechanism, batch experiments, X-ray diffraction (XRD), Fourier transform infrared spectrum (FTIR), X-ray photoelectron spectroscopy (XPS) measurements, and density functional theory (DFT) calculations were performed. Our batch adsorption experiments showed that MMT exhibits a higher adsorption capacity for BPS than for BPA. The XRD analysis also suggested that BPA and BPS could enter the interlayer of MMT. FTIR and XPS results revealed that The Ca atoms and the oxygen atoms in the SiO 4 tetrahedra were involved in BPA and BPS adsorption process via non-covalent interactions. The electrostatic potential calculations suggested that the sulfonyl O site and the hydroxyl H site on the BPS molecule are more favorable for interacting with the MMT surface than the hydroxyl O and H sites of the BPA molecule. DFT calculations further confirmed that stronger binding of BPS than BPA onto the (001) surface and the interlayer of MMT. BPA tends to form Ca ion bridges through hydroxyl groups onto MMT. In contrast, BPS prefers to form Ca ion bridges onto MMT through its sulfonyl group and form hydrogen bonds via hydroxyl groups. This study provides new insights into the molecular-scale interactions that control BPA and BPS adsorption onto an important and environmentally-relevant clay mineral, and which affect the fate and behavior of BPA and BPS in soil systems.
研究领域:
环境科学
·
分子生物学
✓ 已验证
DOI
高影响因子
Journal of Cleaner Production
·
2024
·
IF 9.7
Chuantao Wang,Xiang Li,Xueting Lv,Xin Huang,Yueyue Zhao,Tiantian Deng,Jiale Zhang,Jun Wan,Yanzhong Zhen,Tuo Wang
The construction of S-scheme heterojunction with excellent redox ability holds promising prospects for photocatalytic environment remediation. However, the rationally design of the heterojunction interface to achieve efficient charge transfer still faces challenges. In this study, we fabricated a tight-contacted S-scheme heterojunction by in situ anchoring AgI nanoparticles onto WO 3 nanoplates. The significant difference in Fermi energy levels between WO 3 and AgI results in the formation of a space charge region around the interface and bending of the energy band, facilitating directional migration and spatial separation of charge carriers. This contributes to enhanced generation of superoxide radicals (•O 2 − ) and holes (h + ) active species, leading to a significant increase in chlortetracycline (CTC) degradation rate. The apparent rate constant for CTC removal using the WO 3 /AgI (WA-2) is approximately 15 times higher than that observed for pure WO 3 . Furthermore, WA-2 exhibits universal degradation effects on tetracycline (TC) and oxytetracycline (OTC). Molecular dynamics (MD) simulation reveals the synergistic adsorption effect of WO 3 and AgI on CTC and reactive oxygen species molecules. Based on Fukui function calculation of CTC molecules and degradation intermediates, liquid chromatography-mass spectrometry (LC-MS) analysis, photocatalytic degradation pathway over WO 3 /AgI was determined to be sequential demethylation followed by dechlorination and decarbonylation. These findings provide valuable insights into high-performance S-scheme heterojunctions interface design and elucidation of pollutant degradation mechanism.
研究领域:
环境科学
·
材料科学
·
计算化学
✓ 已验证
产品关联
DOI
高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2024
·
IF 5.3
Dongqing Guo,Junhong Jia,Zongyu Zhang,Jie Yang,Jian Wang,Xiaoyu Jiao,Yun Shi,Leping Cai,Nairu He
In effort to reveal the high-temperature lubrication mechanisms of ternary oxides containing Mo/Co/Ni, the tribological characteristics of atmospheric plasma sprayed (APS) NiCrAlY-MoO 3 /CoO composite coatings at elevated temperatures were investigated. The high-temperature lubrication mechanisms of Co/Ni-molybdate formed on worn surfaces were analyzed through experimental analysis and density functional theory (DFT) calculations. The results demonstrate that the coefficient of friction (COF) of NiCrAlY coating after 30 % MoO 3 /CoO added decreased from 0.43 to 0.30 and the wear rate reduced from 5.00 × 10 −5 to 8.32 × 10 −6 mm 3 N −1 m −1 at 800 °C. This is ascribed to the synergistic lubrication effects of the layer crystal structured ternary oxides CoMoO 4 and NiMoO 4 , which are self-generated through tribo-chemical reactions on the worn surface at elevated temperatures. DFT calculations show that the binding energies of Co O (−1.05 eV) and Ni O (−0.61 eV) in the detected ternary oxides CoMoO 4 and NiMoO 4 are weaker than those of the corresponding bonds in binary oxides CoO (−1.99 eV) and NiO (−1.44 eV), and have potential to break more easily at high temperatures. Such layered structures with easy-to-break bonds of the ternary oxides containing Mo/Co/Ni provides excellent lubrication properties in the composite coatings.
研究领域:
材料科学
·
表面工程
·
计算化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2026
·
IF 6.6
Huan Lin,Bin Li,Guangqi Li,Shu Yin,Yong Li,Junhong Chen
Low-temperature Acheson synthesis achieves energy-efficient SiC production; • DFT and experiments reveal the multiscale mechanism of 6H-SiC evolution; • Al-induced electronic reconstruction governs surface energy and morphology evolution. To achieve the regulation of 6H-SiC crystal morphology at low-temperatures in the Acheson process, this study investigates the growth direction evolution of 6H-SiC by altering the surface energy differences between crystal planes through Al doping, using a combination of density functional theory (DFT) calculations and experimental methods. DFT calculation results reveal that Al doping exerts differentiated effects on the surface energy of various 6H-SiC crystal planes through the modulation of electron distribution and reconstruction of local chemical bonding environments, which further alters the relative plane stability and surface energy anisotropy. This mechanism provides theoretical support for morphology regulation of 6H-SiC via doping in the low-temperature Acheson process. Experimental results demonstrate that Al doping facilitates the thickening of 6H-SiC particles and induces gradient morphological evolution correlated with the <0001> direction, which is consistent with the variation of surface energy anisotropy predicted by DFT calculations. Download: Download high-res image (106KB) Download: Download full-size image
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2026
·
IF 9.1
Xianyao Yan,Xinhui Ji,Jiawei Chen,Rongyue Sun,Huaqiang Chu
The sorption-enhanced steam gasification of biomass using CaO-based materials is considered a promising method for H 2 production, while the presence of H 2 S in the syngas results sulfur poisoning of the materials. In this work, DFT calculations were combined with experimental verification to elucidate the mechanism of H 2 S resistance and structural stability of Ce-doped CaO material. The theoretical results reveal that Ce-doping significantly modulates the surface electronic structure, and Ce-doped CaO surface exhibits less negative H 2 S adsorption energies and higher activation barriers for the initial dissociation steps compared with pristine CaO, thus the onset of the sulfidation reaction is inhibited. Furthermore, the formation of oxygen vacancies is energetically less favorable on Ce-doped CaO surfaces, which is a prerequisite for sulfidation reaction. Even under sulfur-poisoning conditions, the Ce-doped CaO retains superior CO 2 adsorption, and the adsorption of Ca 4 O 4 clusters demonstrates that a robust chemical anchoring effect was introduced by Ce-doping. Experimental results from 20 cycles of steam gasification of high‑sulfur Enteromorpha prolifera validate these theoretical findings, and Ce-doped CaO maintains high H 2 production and CO 2 capture performances with minimal sulfur-poisoning deactivation.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Water Process Engineering
·
2026
·
IF 6.6
Geng Xiang,Zhiguo Shao,Zhansheng Wang,Chunmao Chen,Qianwei Li
In this study, nanostructured Fe-loaded biochar (Fe-BC) was prepared from rice husk via pyrolysis using K 2 FeO 4 as an activator, and applied for the adsorption of pyridine. The structure of Fe-BC was systematically characterized by BET, SEM, XRD, FTIR, and XPS. The results revealed a high specific surface area of 434.2183 m 2 /g. The activating role of K 2 FeO 4 not only enabled the abundant loading of Fe 3 O 4 and Fe 2 O 3 on the biochar surface but also increased the oxygen-containing functional groups, thereby providing active sites for pyridine adsorption. The maximum adsorption capacity of Fe-BC toward Pyridine was 79.796 mg/g. The pseudo-second-order kinetic and Langmuir isotherm models were well suited to describe the Pyridine adsorption process onto Fe-BC. Thermodynamic analysis revealed that after K 2 FeO 4 modification, the negative Gibbs free energy change (ΔG) indicated a spontaneous adsorption process, while the positive enthalpy change (ΔH) and entropy change (ΔS) confirmed the endothermic nature of the adsorption and an increase in randomness at the solid-liquid interface. DFT calculations demonstrated a reduction in the energy gap (ΔE) upon the loading of OH, COOH, and Fe. Among all modifications, Fe loading resulted in the most substantial reduction in ΔE, reaching a minimum value of 0.066 eV. This ultimately demonstrates a significant enhancement in the surface reactivity of the Fe-modified biochar. Integrated DFT simulations and experimental characterization elucidated that the adsorption of pyridine by Fe-BC is governed by a combination of mechanisms, including electrostatic interactions, pore filling, π-π interactions, hydrogen bonding, and surface complexation.
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2026
·
IF 9.1
Shuting Chen,Yuqi Tong,Chenchen Zhan,Yutian Wang,Muhang Cai,Jisiyuan Qin,Huiyu Xu,Kun Wu,Yunhan Tang,Shan Jiang,Genyang Cao
In this study, a bilayer soft and bendable carbon aerogel was fabricated by combining sodium alginate (SA) aerogel with cotton fabric. Using the fabric as a supporting scaffold, a uniform aerogel coating and controlled carbonization were achieved, resulting in a significant increase in accessible adsorption active sites. Compared with pure SA aerogel, which suffers from severe shrinkage during carbonization, the bilayer SA/fabric carbon aerogel exhibited substantially enhanced adsorption capacity. Further investigation into the adsorption mechanism revealed that dye adsorption primarily relies on sodium and oxygen species retained after carbonization of SA, while nitrogen doping plays a key role in tailoring the porosity of the carbon matrix. DFT calculations further confirmed that carboxyl sites on the carbon substrate possess stronger binding energy with dye molecules than nitrogen sites. Electrostatic potential and frontier orbital analyses demonstrated enhanced interfacial charge transfer and orbital coupling at carboxyl edges, clarifying the origin of the superior adsorption performance. The final adsorption performance confirmed the great promise of this bilayer carbon aerogel in the field of dye adsorption.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）