PROGRESS IN ORGANIC COATINGS
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2024
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IF 6.5
Beibei Chen,Wenquan Dong,Wenchao Shi,Xuanlin Li,Bi Yang,Yang Tong,Lin Zhang,Jianzhang Wang
Developing high-performance of organic solid lubricating coating is of great significance for extending the life of the moving systems/parts. Herein, the non-covalently modified h-BN nanosheets by graphene oxide (BNNSs/GO) were elaborately constructed to enhance the mechanical, friction and wear properties of epoxy nanocomposite coating. The microstructure feature and chemical composition of BNNSs/GO were determined by various spectroscopic techniques. The tribological performance of nanocomposite coatings were tested using ball-on-disc friction tester, and 440C stainless-steel ball with diameter of 8 mm was used as the counterface material. The GO nanosheets acted an active platform for BNNSs, which improved the dispersion of BNNSs and interface interaction with epoxy. The anchoring BNNSs could break the strong π-π, and van der Walls forces among GO nanosheets. The thickness of epoxy nanocomposite coatings was about 60 μm. And the epoxy-1.0 wt%BNNSs/GO demonstrated much higher hardness and elastic modulus than epoxy, increased by 112.62 % and 53.37 %, respectively. The coefficient of friction (COF) and wear rate of epoxy-1.0 wt%BNNSs/GO were the lowest, with a reduction of 89.7 % and 97.5 %, respectively. The synergistic lubricating mechanism of epoxy-BNNSs/GO coating was proposed, which could provide a new light on the design of high antifriction and wear resistance of organic nanocomposite coating.
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POLYMER
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2024
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IF 4.1
Zaoxia Wen,Liang Xu,Xingyu Liu,Linxuan Fang,Lianbin Wu
A novel method was developed for constructing cross-linked silsesquioxane, utilizing Q-type H-POSS as a precursor. The Piers-Rubinsztajn (P–R) like reaction of Q-type H-POSS was catalyzed by B(C 6 F 5 ) 3 , resulting in the production of a prepolymer containing partial Si–H. Upon heating at high temperature in air, the prepolymer transformed into an insoluble and infusible cross-linked polymer, named Cured poly(H-POSS). This polymer exhibited high thermostability, with a 5 % weight loss temperature ( T 5d ) of 709 °C and a residue of 92 % at 800 °C. Additionally, Cured poly(H-POSS) exhibited high transparency, with a transmittance of 90 % in the 400–800 nm wavelength range, and favorable dielectric properties, with a dielectric constant ( D k ) of 2.88 at 14 GHz.
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CATALYSIS COMMUNICATIONS
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2024
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IF 3.4
Chenan Yang,Yi Liu,Ying Hu,Peng Wang,Yuling Yang,Shangxing Chen,Zongde Wang,Xiang Li
Catalytic valorization of biomass into high energy density fuels plays a vital role in order to achieve future carbon neutrality. Herein, a class of H-MZ-5 catalysts with different mesoporous pore structures and acid site properties were synthesized. Among them, HMZ-5 prepared with tetrapropylammonium bromide (TPABr) and hexadecyltrimethylammonium bromide (CTAB) as templating agents showed the most excellent catalytic activity and selectivity of α-pinene dimerization. Under optimal catalytic conditions, 100% α-pinene was converted with 89.6% selectivity to dimers. The efficient catalytic activity and affordability of the catalysts in this system make it promising for industrial applications.
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高影响因子
Catalysts
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2024
·Vol. 14
·期 4
·248
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IF 3.8
Xinyi Xing,Wanni Liu,Siquan Xu,Jianxiu Hao
H-Beta zeolite is a solid acid catalyst commonly utilized in the catalytic conversion of biomass resources. In this study, H-Beta zeolite was calcined at different temperatures (350, 550, 750, and 1000 °C) to explore the effects of high temperature-induced dealumination on its physicochemical properties and its catalytic ability to convert glucose into 5-hydroxymethylfurfural (HMF). It was shown that as the calcination temperature increased, the Si-O-Al bond of H-Beta zeolite was broken and its dealumination effect was enhanced. Dealumination led to the collapse of the framework of H-Beta zeolite and a reduction in the number of acid sites, which in turn reduced its catalytic performance and the efficiency of HMF formation from glucose. Furthermore, H-Beta zeolite exhibited an extraordinary catalytic ability for the production of HMF from carbohydrates. Using glucose and cellulose as substrates, superior HMF yields of 91% and 46%, respectively, were achieved under optimal reaction conditions. Further, calcination removes carbon deposits in the recovered H-Beta zeolite, but it affects the cycling stability of the catalyst. Meanwhile, the by-products formed during the synthesis of HMF from glucose catalyzed by H-Beta zeolite catalyst were also clearly detected.
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Journal of Materials Chemistry A
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2024
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IF 10.7
Zhichao Ma,Chenyi Wang,Tianfang Yang,Gangya Wei,Jinrui Huang,Mengran Liu,Kun Zhang,Zunjie Zhang,Yang Liu,Shuyan Gao
Electrocatalytic nitrate (NO3−) reduction to ammonia (NH3) (NRA) is of great significance for solving the problem of urgent NO3− pollution in the environment and opening up a new route to synthesize NH3. However, NRA is limited by its multi-electron/proton transfer process and the NRA process relies heavily on atomic H* produced by H2O splitting, undergirding the necessity for effective NRA catalysts. Herein, three-dimensional (3D) porous phosphorus (P)-doped Cu–Ni alloy materials are constructed through a one-step electrodeposition synthesis. 3D porous materials modulate hydrophilicity and enrich active sites. The Cu d-band center can be tuned through Ni alloying to modify the adsorption energies of intermediates such as *NO3−, *NO2−, and *NH2. The hydrogenation evolution capacity of P promotes the hydrogenation process in the atomic H* path and effectively accelerates the NRA reaction rate. Density functional theory (DFT) calculations demonstrate that the charge transfer between the negatively charged Pδ− and the positively charged Niδ+ and Cuδ+ assists in generating more atomic H* for coupling with reaction intermediates, showing an enhanced catalytic activity at low overpotential. The optimal sample exhibits an exceptional NRA performance with an ammonia yield rate of 848.1 μmol h−1 cm−2 and a faradaic efficiency of 96.1%. This work provides a strategy for creating effective NRA catalysts through enhancing the atomic H* reduction strategy.
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INORGANIC CHEMISTRY
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2024
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IF 4.3
Yu Gu,Zhiqiang Tao,Shujia Zhang,Xiaohui Wang,Hao Yan,Xinmei Liu,Lei Wang,Jun Xu,Hui Shi
Methane–propane coaromatization (MPCA) upgrades two abundant and inexpensive light alkanes into value-added aromatic products. While Ga-loaded MFI zeolites represent by far the most promising catalysts for MPCA reaction, they often contain a sizable portion of Ga species at the external surface of zeolites, which are remote from the Brønsted acid sites (BAS) within MFI pores and thus inefficient for MPCA. Here, we show that Ga can be introduced into MFI pores at fairly high loadings via a simple cocrystallization approach, yielding catalysts possessing well-dispersed Ga sites predominantly residing inside the pores and framework. Adjacency between Ga and BAS within the constraints of MFI channels makes these (Ga, Al)-H-MFI catalysts more active toward methane and propane activation and more selective toward aromatics compared to the Ga/MFI counterparts prepared by impregnation that inevitably leaves a large fraction of Ga at the external surface (i.e., without confinement and few adjacent BAS). Further, the effects of the Si/Al ratio on MPCA performance have been investigated for (Ga, Al)-H-MFI catalysts. Due to the multifold roles of BAS in the overall reaction sequence, an increased BAS concentration generally results in higher propane conversion and productivity of aromatics together with lower net methane conversion and severer coking.
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PubMed
高影响因子
MATERIALS RESEARCH BULLETIN
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2024
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IF 5.3
Yu Chang,Jianan Zhang,Ivan S. Babichuk,Hailong Liu,Yijie Liu,Jian Yang
The release of ammonia (NH 3 ) in industry or daily life is harmful to human health. A gas sensor was developed using h -MoO 3 nanorods and graphene film to detect and eliminate this. The h -MoO 3 nanorods were first synthesized by chemical bath deposition using ammonium molybdate tetrahydrate (NH 4 ) 6 Mo 7 O 24 •4H 2 O and HNO 3 and then deposited on the graphene film transferred to SiO 2 /Si substrate by electrochemical bubbling method. Subsequently, gas-sensitive h -MoO 3 @Graphene composite films were prepared and analyzed using Raman, XRD, SEM, and UV–vis. The gas sensor's performance was evaluated to detect NH 3 at a room temperature concentration range of 1–60 ppm. Compared with graphene, the conductivity of the composite film with 10 mg/ml h -MoO 3 nanorods was increased by 40 % and the sensitivity increased by 10 times. The sensor h -MoO 3 @G-10 showed the best sensing performance to 1 ppm NH 3 . Sensor sensitivity, response and recovery time are 1.1 %, 46.8 s and 17.8 s.
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Journal of Environmental Chemical Engineering
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2024
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IF 7.4
Yuhang Ren,Yu Tian,Yating Lu,Dongyu Nie,Huayi Zhu,Xia Yang
Malathion (MA) is a widely used organophosphorus pesticide globally. Developing efficient photocatalysts is crucial for eliminating MA pollution in water by photocatalytic technology. This study focuses on preparing a series of H-PDI supermolecule/NH 2 -MIL-101(Fe) (PM) materials by amidating NH 2 -MIL-101(Fe) with the more stable H-PDI supermolecule, forming a covalent O C–NH bond. Among these materials, 40 %PM (indicating a mass percentage content of 40 % H-PDI supermolecule in PM) exhibited the best performance for degradation of MA. Under simulated sunlight irradiation of a 10 mg·L 1 MA solution for 180 min, the reaction rate constants of 40 %PM were 5.95 times and 3.13 times higher than those of NH 2 -MIL-101(Fe) and H-PDI supermolecule, respectively. The enhanced performance is attributed to the formation of Z-scheme heterojunctions in the 40 %PM composite lead to fast separation of photogenerated e − and h + . Combining the results of HPLC-MS with Fukui Function, the HOMO, LUMO, and pathway of degradation of MA attracted by 1 O 2 , •OH, and h + were speculated. The pathway involves oxidation, demethylation, P-S bond breakage, decarboxylation, and final conversion to some inorganic molecules. The toxicity of the degradation byproducts were lower than that of MA estimated by Toxicity Estimation Software Tool.
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ELECTROCHIMICA ACTA
·
2025
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IF 5.6
Yan Zhou,Desheng Sui,Qi Yin,Hui Zhang,Jiabing Luo,Guizheng Qi,Wenhui Zhang,Hailin Ma,Jun Zhang
Ammonia has recently been recognized as a promising energy carrier for long-term and large-scale energy storage. Direct ammonia fuel cells (DAFCs) stand out among ammonia utilization technologies due to their high theoretical energy conversion efficiency and environmental compatibility. Although Pt has been widely regarded as the most effective electrocatalyst for ammonia oxidation in alkaline media compared to other noble metals, designing composite structures of Pt to improve the AOR performance of Pt-based catalysts through carrier modulation is still the best solution for designing fuel cell anode materials at present. This work presents an electrochemical synthesis strategy for in situ reduction of [PtCl 6 ] 2− precursors into Pt nanoparticles anchored on NiFe-layered double hydroxide/nickel foam substrates. The unique structure supplies sufficient OH ad for the gradual dehydrogenation of Pt, the two-dimensional layered structure provides a vast loading space for Pt, and more importantly, the bimetallic nature of LDH modulated the electronic state of Pt and thus further regulated the adsorption state of Pt with N 2 H 4 and was verified by in situ IR spectroscopy, which facilitated the reaction towards the G-M mechanism, reduced the toxicity of the *N atoms, and improved the CV cycling stability of the catalyst. The study of the composite structure of Pt and LDH provided a new approach for the exploration of Pt composite catalysts used in the anode catalysts of DAFC.
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CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Shuangxi Lin,Longchen Gong,Ning Zhao,Huibo Zhao,Feigang Zhao,Yang Bai,Zhenhua Li,Wen Liu
Modulating metal-support interactions is critical for improving catalytic activity and product selectivity for CO 2 hydrogenation. Such modulation can be achieved by modifying the metal nanoparticles as well as the supports. Here, we prepared a novel catalyst, in which Ni nanoparticles were dispersed on CeO 2 and hexagonal boron nitride (h-BN) hybrid supports. The introduction of h-BN to Ni/CeO 2 -BN effectively improves the dispersion of Ni nanoparticles. More importantly, the abundant Ni-CeO 2 interfacial sites with enriched oxygen vacancies are formed over h-BN edge sites. The dispersed Ni species are anchored on CeO 2 via a unique interfacial structure, with electron-rich Ni (Ni δ− ) species. At the interfacial sites on Ni/CeO 2 -BN, the synergy between oxygen vacancies and Ni δ− , which enhances CO 2 activation and H 2 dissociation, respectively, renders superior catalytic performance for CO 2 methanation. In situ DRIFTS suggests formate as key rate-limiting intermediates on Ni-CeO 2 sites, while the formation of B-H bonds further promotes hydrogen activation and subsequently the catalytic performance. The modulation of metal-support interactions by spatial confinement effect by BN offers a new paradigm for designing metal/oxide catalysts for chemical transformations that requires bifunctionality as CO 2 hydrogenation.
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Molecular Catalysis
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2024
·
IF 3.9
Guiyu Chen,Wei Liu,Shiqiang Wang,Yongxiang Miao,Zhibin Song
Quinazolinone-based boron difluoride (BF 2 ) complexes were developed for the synthesis of dihydroisoquinolones, 2-phenylisoindolinone, 1-isochromanone and diarylketone through α-C(sp 3 )-H photooxidation. Seven selected quinazolinone-based BF 2 complexes exhibited good activity for photooxidation reaction using air as oxidant. It is worth noting that quinazolinone-based BF 2 as photocatalysts do not require the introduction of halogen heavy atoms to improve catalytic activity. Mechanism exploration indicated these BF 2 catalysts may involve a single electron transfer (SET) mediated photoredox catalysis to achieve α-C(sp3)-H oxidation. These quinazolinone-based BF 2 catalysts with facile preparation and structural modifiability would be good choice for organic oxidative transformation in the future.
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SOLAR ENERGY MATERIALS AND SOLAR CELLS
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2024
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IF 6.3
Jianfeng Hu,Jianbin He,Yanping He,Xiaoming Fang,Zhengguo Zhang
Encapsulated phase change materials (MPCMs) can be used to address thermal runaway issues in electronic devices and battery systems in small spaces or flexible requirements. In this work, polyurea microcapsules incorporating h-BN and encapsulating n-eicosane were successfully synthesized. The h-BN was embedded to enhance the microcapsules' thermal conductivity. Comprehensive characterizations revealed that the microcapsules' area change rates before and after phase transition were approximately 3 %. Among the various microcapsules, h/MC-2 exhibited the best performance, with an enthalpy value of 184.37 J/g, an encapsulation efficiency of 79.72 %, and a high thermal storage efficiency of up to 99 %. Moreover, the thermal conductivity coefficient increased by 51.24 % to 0.3297 W/(m·K) due to the addition of h-BN. Mechanical properties testing was conducted on individual h/MC-2 microcapsules, revealing an average nominal rupture tension of 46.31 ± 2.09 N/m and an average Young's modulus of 0.17 ± 0.01 GPa. Furthermore, the h/MC-2 microcapsules were combined with silicone gel to prepare composites, incorporating h-BN to enhance thermal conductivity. The composites were found to reduce the simulative chip temperature by 15.90 %, demonstrating their potential application in thermal management.
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