Journal of Materials Chemistry A
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2020
·Vol. 8
·期 18
·9049-9057
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IF 11.301
Qifeng Yang,Peng Jin,Bing Liu,Liang Zhao,Jiahao Cai,Zhan Wei,Shouwei Zuo,Jing Zhang,Lai Feng
Encapsulating metallic nanoparticles (NPs) with a graphitic carbon shell is a promising strategy to achieve highly efficient and stable electrocatalysts for the hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and electrochemical overall water splitting (OWS). This work presents a simple and facile synthesis of graphitic carbon coated NixRuy alloys. The optimized catalyst (e-Ni0.6Ru0.4@C) displays an ultrafine morphology and outstanding HER and OER activities in alkaline media, which are among the best reported so far for various carbon-based electrocatalysts. Remarkably, the e-Ni0.6Ru0.4@C‖e-Ni0.6Ru0.4@C pair needs a low cell voltage of 1.51/1.62 V for driving OWS to reach 10/100 mA cm−2, far outperforming the benchmark electrode pair Pt/C‖RuO2. As expected, this carbon-based catalyst also exhibits superior durability as compared to that of precious catalysts. The experimental evidence combined with density functional theory (DFT) computations thus demonstrates for the first time that minor Ru alloying enables not only the morphological modulation but also the fine electronic modification of the catalyst, which both facilitate the overall electrochemical reactions on the carbon shell surface. Thus, our results may further shed light on how to design and optimize carbon-based electrocatalysts to achieve enhanced catalytic performance for OWS.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
CRYSTENGCOMM
·
2020
·Vol. 22
·期 25
·4268-4274
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IF 3.117
Dan Lin,Qinxin Luo,Hui Zheng,Lulu Tang,Wenqi Zhan,Kaibin Tang
A new quaternary oxygen-free cobalt-based compound, SmCoAsF, which crystallizes with a tetragonal ZrCuSiAs-type structure, was synthesized via a solid state metathesis (SSM) reaction. The lattice constants a and c of SmCoAsF were 3.9555(0) Å and 8.2462(2) Å, respectively. Based on the measurements of electrical resistivity and magnetization, it was inferred that the as-synthesized sample mainly underwent a ferromagnetic (FM) transition at Tc ∼ 70 K, followed by an antiferromagnetic (AFM) transition at a lower temperature, TN1 ∼ 40 K. The third magnetic transition at TN2 ∼ 6 K was also observed clearly in the magnetic measurements. SmCoAsF with a rich magnetic phase is expected to be a new member of the quaternary cobalt-based system and contribute to the explorations of the origin of magnetic state transitions.
研究领域:
材料科学
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磁性材料
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固体化学
✓ 已验证
DOI
高影响因子
CHEMICAL PHYSICS LETTERS
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2019
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IF 1.901
Shenghan Zhang,Yang Jiao
Aqueous ammonia is a potential absorbent for post-combustion carbon capture. Desorption of carbon dioxide (CO 2 ) from ammonium bicarbonate (NH 4 HCO 3 ) solution is one of key reactions of regeneration of the absorbent. Experimental studies on decomposition of NH 4 HCO 3 solution with and without nano-TiO 2 at different temperatures were conducted. Additions of nano-TiO 2 into ammonium bicarbonate solutions decrease the apparent activation energy of overall decomposition reaction and accelerate the decomposition of ammonium bicarbonate solutions. Moreover, compared to hydrophilic nano-TiO 2 , hydrophilic lipophilic nano-TiO 2 exerts more significant promoting effects on the decomposition reaction.
研究领域:
化学工程
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
VACUUM
·
2021
·
IF 3.627
Zhaowang Dong,Xueyi Guo,Bin Yang,Heng Xiong,Wenlong Jiang
Lead sulfide (PbS) is the main component of galena. The traditional method used to prepare metal lead from galena is disadvantaged by high energy consumption and severe pollution. In this paper, an eco-friendly yet simple process is proposed to prepare high-purity metal lead directly from lead sulfide. According to thermodynamic calculation, lead sulfide can be decomposed into metal lead under vacuum. The pathway to decomposition is based on the reaction of 2PbS (s) = 2 Pb (l) + S 2 (g). Besides, an investigation was conducted into the impact of temperature and holding time on the quality of decomposition products and the purity of lead in residue. The investigative results show that the decomposition rate of lead sulfide reached its maximum at 1050 °C for 60 min, which is about 50%, and the purity of the lead in the residue reached 99.51%. When the temperature reached above 1100 °C and the holding time exceeded 40 min, the purity of lead reached as high as 99.81%, but the quality of the residue stayed low. This method contributes a fresh idea to the eco-friendly utilization and efficient purification of galena for preparing high-purity metal lead.
研究领域:
冶金学
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环境科学
✓ 已验证
DOI
高影响因子
Catalysis Science & Technology
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2014
·Vol. 4
·期 11
·4010-4019
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IF 4.76
Chao Lin,Kai Tao,Hongbo Yu,Dayin Hua,Shenghu Zhou
Molybdenum-doped mesoporous SBA-15, mesoporous SBA-15-supported MoO3/SBA-15, and traditional silica-supported MoO3/SiO2 were successfully synthesized. Various techniques, such as XRD, TEM, BET, UV-DRS, Raman, XPS and IR, were used to characterize the above obtained materials. The studies of TEM, XRD and BET confirmed that the highly ordered mesoporous structure of SBA-15 was maintained in the doped Mo-SBA-15 whereas supported MoO3/SBA-15 showed a significant reduction in surface area due to the deposition of MoO3 nanoparticles into the SBA-15 channels. XPS studies revealed that a high concentration of Mo5+ species appeared in doped Mo-SBA-15 whereas supported MoO3/SBA-15 and MoO3/SiO2 only contained Mo6+ species. The metathesis reaction of 1-butene and ethene to propene was used to evaluate the catalytic performance of Mo-containing materials. The doped Mo-SBA-15 illustrated a superior catalytic performance over the supported MoO3/SBA-15 and MoO3/SiO2 catalysts. The enhancement of catalytic performance for doped Mo-SBA-15 was assigned to the incorporation of Mo species into the SBA-15 framework. Due to the doping method, Mo-SBA-15 exhibited a well-ordered mesoporous structure, a high surface area, and a high concentration of Mo5+ species, which is beneficial to the catalytic performance for metathesis reactions.
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Xinjian Zhou,Ruixuan Xu,Hongqi Nie,Qilong Yan,Jun Liu,Yunlan Sun
Burning rate modulation is a crucial but challenging technology for designing solid propellants. The core–shell structured Al@AP and Al@AP/CuO were prepared and their thermal reaction properties were investigated at different pressures. The precise catalytic mechanism of doped CuO in oxidizer and the key reason for its burning rate modulating effect on solid propellants were elucidated by combining DFT calculations. The *NH 4 ClO 4 on the CuO (1 1 1) surface is more likely to undergo a dehydrogenation reaction first. The large difference in activation energy between *NH 4 ClO 4 →*NH 3 +*ClO 4 +*H and *NH 4 ClO 4 → NH 3 + HClO 4 explains the reasons that CuO can reduce the ignition delay of the Al@AP. CuO promotes the decomposition of the AP@Al at the low- and high-temperature decomposition (LTD and HTD) stage. For the Al@AP-CuO, the temperature of the high-temperature decomposition peak (THTD) does not shift to the lower temperature range with increasing pressure. These results are responsible for a reduction of pressure exponent in the presence of minor CuO as reported in the literature. CuO can facilitate the transformation process *NH 3 →*NH 2 on the CuO (1 1 1) surface at low-temperature and low-pressure conditions. However, at high-temperature and high-pressure conditions, it can inhibit the reaction *NH 2 →*NH→*N, so the burning rate of solid propellants can be controlled.
研究领域:
材料科学
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化学工程
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计算化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2022
·
IF 7.139
Ze-Wei Wu,Jing Xiong,Cun-Wen Wang,Yuan-Hang Qin
Although supported Ni is generally considered the most active non-noble metal catalyst for decomposing NH 3 to produce CO x -free H 2 , its activity is not sufficient. Herein, supporting high-loading Ni on SBA-15 is explored to alleviate the low intrinsic activity issue of Ni. SBA-15 supports with tunable textual properties are synthesized to support Ni catalyst for NH 3 decomposition. Characterization shows that Ni catalyst with a loading close to 40 wt% supported on SBA-15 with the largest specific surface area (Ni/SBA-15-80) exhibits a NH 3 decomposition performance much better than those reported on other Ni-based NH 3 decomposition catalysts, resulting from its favorable textural properties and high Ni loading. In addition, Ni/SBA-15-80 shows excellent catalytic stability, with no activity degradation over an 80-h NH 3 decomposition test. This work reveals the importance of textural properties of support and Ni loading to NH 3 decomposition performance and can provide a new idea for synthesizing high-performance NH 3 decomposition catalysts.
研究领域:
材料科学
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催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
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2019
·Vol. 141
·期 2
·783-796
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IF 2.471
Ding Jiong,Yu Liming,Wang Xiaona,Xu Qiyue,Yang Suijun,Ye Shuliang,Jiang Juncheng
The accelerating rate calorimetry is a powerful tool for thermal hazard evaluation. However, the existing kinetics approaches ignore the fact that the thermal inertia is varying during the pseudo-adiabatic reaction because of the changing of the sample’s heat capacity and heat loss. To overcome this shortcoming, the expression of the thermal inertia is amended based on the heat balance and transfer in this article. The arithmetic product of the sample’s heat capacity and the amended thermal inertia is obtained by merging the kinetic results of the DSC and ARC data. Then, the data from the ARC are corrected and the more reasonable values of the kinetic parameters are computed based on the varying thermal inertia consideration. With the typical n -order and autocatalytic decomposition experiments under the different sample masses, the validity of the proposed kinetic approach is verified. Meanwhile, the hypotheses of the proposed approach are analyzed and discussed in the end of the article.
研究领域:
化学工程
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安全科学
✓ 已验证
产品关联
DOI
高影响因子
SOLID STATE SCIENCES
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2022
·
IF 3.752
Kun Song,Xiaodong Lv,Yuntao Xin,Yong Li,Xuewei Lv
Owing to their unique structure, polyoxometalates (POMs) are important compounds with both acidic and oxidizing properties that can be used in acid-catalyzed and redox-catalyzed reactions, as well as in medicinal chemistry and as functional materials . Vanadium-based polyoxometalate materials are an important class of POMs, in which Na 6 V 10 O 28 is a common vanadium-based polyoxometalate produced by condensation and dehydration in acidic vanadium-containing solutions. However, the properties of the compound were reported extensively, but thermodynamic data and thermal stability were hardly available. In this study, Na 6 V 10 O 28 material was synthesized by the liquid phase method and characterized by XRD , thermogravimetry , electron microscopy , and infrared analysis. The results show that the prepared material is Na 6 V 10 O 28 ·18H 2 O and its decomposition product was Na 5 V 12 O 32 . The thermodynamic data of Na 6 V 10 O 28 . nH 2 O and Na 5 V 12 O 32 such as heat capacity, entropy, and enthalpy were calculated by the NKR combined with drop calorimetry . Finally, the obtained data were applied to equilibrium thermodynamic calculations for reactions related to Na 6 V 10 O 28 , including condensation reactions, ammonium salt precipitation, thermal decomposition reactions , and hydrolysis precipitation. The results can be used for theoretical calculations of thermodynamic reactions related to Na 6 V 10 O 28 and Na 5 V 12 O 32 .
研究领域:
材料科学
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物理化学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
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2022
·Vol. 46
·期 7
·3409-3416
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IF 3.925
Hao Liu,Yaowei Wang,Fengqi Zhang,Congcong Xu,Xiaoyuan Liao,Yan Jiang,Shuxiang Lu
A series of K-based oxide catalysts supported on aluminium oxide (γ-Al2O3) with different surface areas were synthesized using an impregnation method and investigated by the decomposition of sulfones from oxidized diesel fuels. The synthesized catalysts were characterized by N2 adsorption–desorption isotherms, CO2-TPD and HR-SEM methods to explore the relationship between the structure of the catalysts and sulfone conversion. The results showed that the K element was highly dispersed on the surface of γ-Al2O3. The prepared catalyst was further applied in the decomposition reaction of dibenzothiophene sulfone (DBTS) to evaluate the catalytic performance. The sulfone conversion could achieve 63.9% in 10% K2O/3-Al2O3 within 20-minute reaction time at 260 °C. Moreover, our experimental test showed that the sulfone conversion was linearly correlated with the logarithm of the total basic sites of the K2O/γ-Al2O3 catalyst.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
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2024
·
IF 6.3
Changou Pan,Zhirong Shi,Ruochen Zhang,Peng Liu
Metathetic degradation has been recognized as promising strategy for the treatment of waste vulcanized rubbers as a Waste-to-Resources approach, not only eliminating the pollution but also recycling as resources. However, it was mainly used for the treatment of the waste vulcanized natural rubber, which contains plentiful cis -1,4- structure. Despite of a much higher consumption of the emulsion type butadiene-based rubbers than natural rubber, there was no report on the metathetic degradation of the waste vulcanized emulsion type butadiene-based rubbers due to their less cis -1,4- unit, although the metathetic functionalization of the nonvulcanized emulsion type butadiene-based rubbers have been well reported. Here, the metathetic degradation of waste vulcanized emulsion type butadiene-based rubber was explored with nitrile-butadiene rubber (NBR) glove as a model. Different from the metathetic degradation of waste vulcanized natural rubber via only cross metathesis between cis -1,4-structure and the chain transfer agent (CTA), the ring closing metathesis between the adjacent cis -1,4-structure and 1,2-structure also occurred in the metathetic degradation of waste vulcanized NBR. It is expected to open the door for the Waste-to-Resources approach of all waste vulcanized emulsion type diene-based rubbers.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2016
·
IF 3.652
Huidong Zheng,Jinliang Chen,Chao Li,Jingjing Chen,Yingshu Wang,Suying Zhao,Yanru Zeng
Myrcene, an important intermediate for the production of fine chemicals and pharmaceuticals, is mainly produced by the pyrolysis of β-pinene in the industry. The study of the direct pyrolysis of β-pinene was carried out without a catalyst and carrier gas at 573–873 K and under low pressure. In order to clarify the reaction mechanism, the primary intermediates of β-pinene pyrolysis including myrcene and limonene were also used as raw materials for further pyrolysis. The identification of some small molecules and C 10 H 16 isomers in the products proves that both decomposition reaction and ene reaction take place during the pyrolysis process. Based on the qualitative and quantitative analysis of reaction products, a reaction scheme for the pyrolysis of β-pinene was proposed. With appropriate simplification of the reaction scheme, a phenomenological kinetic model of the competitive parallel and consecutive first-order reaction was built, and exhibited good agreement with the experimental data. The activation energy ( E a ) and pre-exponential factor ( k 0 ) for each pathway were also determined.
研究领域:
化学工程
·
有机化学
✓ 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）