JOURNAL OF CHEMICAL THERMODYNAMICS
·
2018
·
IF 2.631
Jing Miao,Kun-Xian Wu,Zhi-Hong Liu
Two pure mixed alkali-transition metal borates, Li 6 Zn 3 B 4 O 12 (s) and Na 3 ZnB 5 O 10 (s) have been synthesized and characterized by XRD, FT-IR, and chemical analysis. For Li 6 Zn 3 B 4 O 12 , the molar enthalpy of solution of Li 6 Zn 3 B 4 O 12 in the mixture solvent of {2.00 mL of 1 mol·L −1 HCl + H 3 BO 3 )(aq)} was measured. The molar enthalpies of solution of ZnO(s) in 1 mol·L −1 HCl(aq), and LiBO 2 (s) in the mixture solvent of {2.00 mL of 1 mol·L −1 HCl(aq) + ZnO(aq)} were also measured. For Na 3 ZnB 5 O 10 , the molar enthalpy of solution of Na 3 ZnB 5 O 10 in 2.00 mL of 1 mol·L −1 HCl(aq) was measured. The molar enthalpy of solution of NaBO 2 ·4H 2 O(s) in the mixture solvent of {2.00 mL of 1 mol·L −1 HCl(aq) + H 3 BO 3 + ZnO](aq)} was also measured. With the incorporation of the previously determined enthalpy of solution of H 3 BO 3 (s) in 1 mol·L −1 HCl(aq), and ZnO(s) in {1 mol·L −1 HCl(aq) + H 3 BO 3 }, together with the use of the standard molar enthalpies of formation for LiBO 2 (s)/NaBO 2 ·4H 2 O(s), ZnO(s), H 3 BO 3 (s) and H 2 O(l), the standard molar enthalpies of formation of −(5867.5 ± 4.8) kJ·mol −1 for Li 6 Zn 3 B 4 O 12 and −(4655.3 ± 6.6) kJ·mol −1 for Na 3 ZnB 5 O 10 at T = 298.15 K were obtained on the basis of two appropriate thermochemical cycles.
研究领域:
物理化学
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无机化学
·
热化学
✓ 已验证
DOI
高影响因子
Catalysts
·
2018
·Vol. 8
·期 7
·257
·
IF 3.465
Lin Li,Bo Jiang,Dawei Tang,Zhouwei Zheng,Cong Zhao
Chemical looping reforming (CLR) technique is a prospective option for hydrogen production. Improving oxygen mobility and sintering resistance are still the main challenges of the development of high-performance oxygen carriers (OCs) in the CLR process. This paper explores the performance of Ni/CeO2nanorod (NR) as an OC in CLR of ethanol. Various characterization methods such as N2adsorption-desorption, X-ray diffraction (XRD), Raman spectra, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), H2temperature-programmed reduction (TPR), and H2chemisorption were utilized to study the properties of fresh OCs. The characterization results show the Ni/CeO2-NR possesses high Ni dispersion, abundant oxygen vacancies, and strong metal-support interaction. The performance of prepared OCs was tested in a packed-bed reactor. H2selectivity of 80% was achieved by Ni/CeO2-NR in 10-cycle stability test. The small particle size and abundant oxygen vacancies contributed to the water gas shift reaction, improving the catalytic activity. The covered interfacial Ni atoms closely anchored on the underlying surface oxygen vacancies on the (111) facets of CeO2-NR, enhancing the anti-sintering capability. Moreover, the strong oxygen mobility of CeO2-NR also effectively eliminated surface coke on the Ni particle surface.Keywords:chemical looping reforming;hydrogen;oxygen carrier;CeO2;nanorod
研究领域:
能源科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2016
·
IF 2.196
Yong-Jie Geng,Jie Wang,Zhi-Hong Liu
Two transition metal borates with microporous structures for Na 2 Co 2 B 12 O 21 and Na 2 Cu 2 B 12 O 21 have been synthesized and characterized by XRD, FT-IR, and elemental analysis. The molar enthalpies of solution of Na 2 Co 2 B 12 O 21 (s) and Na 2 Cu 2 B 12 O 21 (s) in 1 mol dm −3 HCl(aq) were measured by microcalorimeter at T = 298.15 K, respectively. The molar enthalpies of solution of CoCl 2 ·6H 2 O(s) and CuCl 2 ·2H 2 O(s) in the mixture solvent of 2.00 cm 3 of 1 mol dm −3 HCl(aq) in which 5.30 mg of H 3 BO 3 and 0.84 mg of NaCl being added were also measured, respectively. With the incorporation of the previously determined enthalpy of solution of H 3 BO 3 (s) in 1 mol dm −3 HCl(aq), together with the standard molar enthalpies of formation for CoCl 2 ·6H 2 O(s)/CuCl 2 ·2H 2 O(s), NaCl(s), H 3 BO 3 (s), HCl(aq) and H 2 O(l), the standard molar enthalpies of formation of – (9072.4 ± 9.7) kJ mol −1 for Na 2 Co 2 B 12 O 21 (s) and – (8887.5 ± 9.7) kJ mol −1 for Na 2 Cu 2 B 12 O 21 (s) at T = 298.15 K were obtained on the basis of the appropriate thermochemical cycles. It is obvious that Na 2 Co 2 B 12 O 21 (s) is more thermal stable than that of Na 2 Cu 2 B 12 O 21 (s).
研究领域:
材料科学
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热化学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2019
·
IF 2.29
Pan Liang,Sa-Ying Li
The s tandard mole enthalpy of formation is an essential feature of chemical compounds, which is critical for assessing the thermal effects of chemical reactions with their participation. In this paper, two pure phases of zinc borates, 2ZnO·2B 2 O 3 ·3H 2 O and ZnB 4 O 7 , have been synthesized by hydrothermal and boric acid flux methods, respectively. They were characterized by XRD, FT-IR and TGA. The molar enthalpies of solution of 2ZnO·2B 2 O 3 ·3H 2 O (s) and ZnB 4 O 7 (s) in 1 mol·dm −3 HCl (aq) were measured at T = 298.15 K, respectively, by the use of an isothermal microcalorimeter. In accordance with Hess’ law, the standard molar enthalpies of formation of the two zinc borates 2ZnO·2B 2 O 3 ·3H 2 O (s) and ZnB 4 O 7 (s) were calculated to be −(4177.02 ± 3.3) kJ·mol −1 and −(2971.1 ± 3.3) kJ·mol −1 , respectively, by the use of standard molar enthalpies of formation for ZnO (s), H 3 BO 3 (s) and H 2 O (l) based on the two designed thermochemical cycles.
研究领域:
无机化学
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物理化学
✓ 已验证
DOI
高影响因子
Energy Technology
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2017
·Vol. 5
·期 8
·1399-1406
·
IF 2.789
Zhong Ma,Rui Xiao,Huiyan Zhang
A technology for hydrogen storage is proposed based on the repeated reduction of magnetite (Fe 3 O 4 +4 H 2 →3 Fe+4 H 2 O) and the oxidization of metallic iron (3 Fe+4 H 2 O→Fe 3 O 4 +4 H 2 ). Herein, we prepared three montmorillonite (MMT)-supported iron oxide samples by using a sol–gel method and demonstrated their application in hydrogen storage through a chemical looping process. The redox performance of the Fe-MMT samples was studied at 600 °C in a fixed-bed reactor. The results showed that 70 Fe-MMT (with 70 wt % Fe 2 O 3 ) exhibited relatively good redox performance owing to its excellent anti-agglomeration ability and sintering resistance. After the redox performance tests, Fe 2 SiO 4 was observed in all Fe-MMT samples. It was worth noting that the diffraction intensity of Fe 2 SiO 4 in 70 Fe-MMT was much weaker than in 30 Fe-MMT (30 wt % Fe 2 O 3 ) and 50 Fe-MMT (50 wt % Fe 2 O 3 ), which was owed to the high MMT content in the 30 Fe-MMT and 50 Fe-MMT samples. The formation of Fe 2 SiO 4 in repeated redox cycles could reduce the stability and recyclability of Fe-MMT samples. This might be the major reason for the better hydrogen storage performance of 70 Fe-MMT compared with 30 Fe-MMT and 50 Fe-MMT.
研究领域:
材料科学
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能源技术
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2022
·Vol. 12
·期 10
·1181
·
IF 4.501
Da Song,Yan Lin,Kun Zhao,Zhen Huang,Fang He,Ya Xiong
CO2resourceful utilization contributes to the goal of carbon neutrality. Chemical Looping Dry Reforming (CLDR) has attracted significant attention as a method for converting CO2to CO. NiFe2O4oxygen carrier (OC) is found to be a potential material for CLDR. However, the migration process of lattice oxygen, which are critical for the conversion of CO2to CO, was not extensively investigated. In this study, the reduction and oxidation degrees of the NiFe2O4were finely modulated in a thermogravimetric analyzer. The lattice oxygen migration mechanism of the NiFe2O4in redox cycles was characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and in-situ Raman. The novelty of this paper is clarifying the release-uptake paths of lattice oxygen during CO2resourceful utilization. The result indicates that the concentration gradient between the surface and the bulk drives the diffusion of lattice oxygen. The stabilization of surface lattice oxygen content is attributed to the rapid migration of O anion, which is closely associated with the movement process of Ni particles inward and outward through the spinel bulk. In addition, a highly reactive chemical reaction interface consisting of lattice oxygen and the corresponding metal atoms is always present on the surface of the oxygen carrier and is confirmed by an in-situ Raman and XPS during the whole process of CLDR. The results of this paper offer reference and basis for further development and design of CLDR using spinel OC.Keywords:chemical looping (CL);oxygen carrier (OC);CO2splitting;lattice oxygen;NiFe2O4
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
Energies
·
2024
·Vol. 17
·期 24
·6314
·
IF 3
Zhiyin Zhang,Huimin Hu,Jie Yang,Zhengguang He,Kai Yan,Tianyu Liu,Chang Wen
The photo-thermochemical cycle (PTC) for water splitting offers a sustainable method for hydrogen production by efficiently utilizing solar energy. This study explored the use of CeO2as a catalyst in the PTC system to enhance hydrogen yield. A nanostructured CeO2catalyst was synthesized via the sol-gel method, achieving an H2yield of 8.35 μmol g−1h−1. Stability tests over five cycles showed consistent yields between 7.22 and 8.35 μmol g−1h−1. Analysis revealed that oxygen vacancies (VOs) increased after the photoreaction and depleted during the thermal reaction, which aligns with the expected PTC mechanism for hydrogen production. Single-factor experiments highlighted that photoreaction duration mainly influenced VOs generation, while thermal duration and temperature impacted VOs consumption and intermediate reaction rates. A response surface methodology (RSM) model predicted optimal conditions for maximum H2yield (8.85 μmol g−1h−1) with a photoreaction duration of 46.6 min, thermal duration of 45.4 min, and thermal temperature of 547.2 °C.
研究领域:
材料科学
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能源科学
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催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
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2015
·
IF 2.679
Hui-Hui Zhang,Na Kong,Jie Wang,Zhi-Hong Liu
Two pure microporous copper borates (NaCuB 7 O 12 · H 2 O and KCuB 7 O 12 · H 2 O) have been synthesised and characterized by XRD, FT-IR, TG techniques and chemical analysis. The molar enthalpies of solution of NaCuB 7 O 12 · H 2 O (s) and KCuB 7 O 12 · H 2 O (s) in 1 mol · dm −3 HCl (aq) were determined to be – (24.12 ± 0.12) kJ · mol −1 and – (35.07 ± 0.08) kJ · mol −1 , respectively. The molar enthalpies of solution of 0.72 mg of NaCl (s) and 0.91 mg of KCl in the mixture solvent of 2.00 cm 3 of 1 mol · dm −3 HCl (aq) which contains 5.3 mg of H 3 BO 3 were measured, respectively. The molar enthalpies of solution of 2.09 mg of CuCl 2 · 2H 2 O (s) in the mixture solvent of 2.00 cm 3 of 1 mol · dm −3 HCl (aq) which contains 5.3 mg of H 3 BO 3 and 0.72 mg of NaCl/0.91 mg of KCl were also measured, respectively. With the incorporation of the previously determined enthalpy of solution of H 3 BO 3 (s) in 1 mol · dm −3 HCl (aq), together with the standard molar enthalpies of formation for CuCl 2 · 2H 2 O (s), NaCl (s)/KCl (s), H 3 BO 3 (s), HCl (aq) and H 2 O (l), the standard molar enthalpies of formation of – (5373.3 ± 5.6) kJ · mol −1 for NaCuB 7 O 12 · H 2 O (s) and – (5375.0 ± 5.6) kJ · mol −1 for KCuB 7 O 12 · H 2 O (s) at T = 298.15 K were obtained on the basis of the appropriate thermochemical cycles. It is obvious that KCuB 7 O 12 · H 2 O (s) is more thermal stable than that of NaCuB 7 O 12 · H 2 O (s).
研究领域:
化学热力学
·
材料科学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2016
·
IF 3.205
Shaojie Xu,Xiangdong Lin,Yong He,Zhihua Wang,Yanwei Zhang,Jianzhong Liu,Kefa Cen
Sulfur-iodine thermochemical cycle is considered as a promising route for hydrogen production without CO 2 emission. In this cycle, the hydrogen iodide conversion rate plays an important role in the total thermal efficiency to some extent. To improve the efficiency of HI decomposition, the homemade carbon membranes supported by α-alumina porous tubes were well-designed in a specific way and evaluated aiming at removing H 2 from HI decomposition reaction side. Permeability, selectivity and stability of self-designed carbon membranes are investigated in some gaseous components in the present work. Firstly, single-component (H 2 /Ar) permeance was observed with differential pressure ranging from 0.05 to 0.2 Mpa. The result shows that differential pressure has little effect on H 2 and Ar permeance. Secondly, the hydrogen and argon permeance through carbon membrane is 3.1 × 10 −8 mol m −2 s −1 Pa −1 and 5.7 × 10 −10 mol m −2 s −1 Pa −1 respectively at 300 °C. The separation factor of H 2 and Ar is 54, which is greater than the theoretical value calculated by Knudsen diffusion equation. Thirdly, hydrogen permeability in the H 2 HI H 2 O gaseous mixture system owns nearly the same as that of the single-component (H 2 ) at 300–500 °C. Due to the large molecule diameter, most of HI are stopped by carbon membrane. However, H 2 O molecules could pass through the carbon membrane obviously. The permselectivity of H 2 /HI is over 310 at 500 °C. Last, after 10 h of stability tests, some slight damage are observed on the surface of carbon membrane according to the scanning electron micrograph (SEM). The structure change of carbon membrane gave rise to a little increase of H 2 permeance at 20–100 °C.
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2014
·
IF 2.423
Jie Wang,Ai-Qing Zhang,Zhi-Hong Liu
Two pure zinc borates with microporous structure 3ZnO·3B 2 O 3 ·3.5H 2 O and 6ZnO·5B 2 O 3 ·3H 2 O have been synthesized and characterized by XRD, FT-IR, TG techniques and chemical analysis. The molar enthalpies of solution of 3ZnO·3B 2 O 3 ·3.5H 2 O(s) and 6ZnO·5B 2 O 3 ·3H 2 O(s) in 1 mol · dm −3 HCl(aq) were measured by microcalorimeter at T = 298.15 K, respectively. The molar enthalpies of solution of ZnO(s) in the mixture solvent of 2.00 cm 3 of 1 mol · dm −3 HCl(aq) in which 5.30 mg of H 3 BO 3 were added were also measured. With the incorporation of the previously determined enthalpy of solution of H 3 BO 3 (s) in 1 mol · dm −3 HCl(aq), together with the use of the standard molar enthalpies of formation for ZnO(s), H 3 BO 3 (s), and H 2 O(l), the standard molar enthalpies of formation of −(6115.3 ± 5.0) kJ · mol −1 for 3ZnO·3B 2 O 3 ·3.5H 2 O and −(9606.6 ± 8.5) kJ · mol −1 for 6ZnO·5B 2 O 3 ·3H 2 O at T = 298.15 K were obtained on the basis of the appropriate thermochemical cycles .
研究领域:
化学热力学
·
材料科学
✓ 已验证
DOI
高影响因子
Green Energy & Environment
·
2020
·
IF 6.395
Li Ma,Yu Qiu,Min Li,Dongxu Cui,Shuai Zhang,Dewang Zeng,Rui Xiao
The chemical looping process, where an oxygen carrier is reduced and oxidized in a cyclic manner, offers a promising option for hydrogen production through splitting water because of the much higher water splitting efficiency than solar electrocatalytic and photocatalytic process. A typical oxygen carrier has to comprise a significant amount of inert support, to maintain stability in multiple redox cycles, thereby resulting in a trade-off between the reaction reactivity and stability. Herein, we proposed the use of ion-conductive yttria-stabilized zirconia (YSZ) support Fe 2 O 3 to prepare oxygen carriers materials. The obtained Fe 2 O 3 /YSZ composites showed high reactivity and stability. Particularly, Fe 2 O 3 /YSZ-20 (oxygen storage capacity, 24.13%) exhibited high hydrogen yield of ∼10.30 mmol g −1 and hydrogen production rate of ∼0.66 mmol g −1 min −1 which was twice as high as that of Fe 2 O 3 /Al 2 O 3 . Further, the transient pulse test indicated that active oxygen diffusion was the rate-limiting step during the redox process. The electrochemical impedance spectroscopy (EIS) measurement revealed that the YSZ support addition facilitated oxygen diffusion of materials, which contributed to the improved hydrogen production performance. The support effect obtained in this work provides a potentially efficient route for the modification of oxygen carrier materials.
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 HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Fuyu Xie,Qingke Yuan,Yukang Qie,Ying Meng,Fubo Luan
Methylmercury (MeHg) uptake by demethylating bacteria and inorganic divalent mercury [Hg(II)] uptake by methylating bacteria have been extensively investigated because uptake is the initial step of the intracellular Hg transformation. However, MeHg and Hg(II) uptake by non-methylating/non-demethylating bacteria is overlooked, which may play an important role in the biogeochemical cycling of mercury concerning their ubiquitous presence in the environment. Here we report that Shewanella oneidensis MR-1, a model strain of non-methylating/non-demethylating bacteria, can take up and immobilize MeHg and Hg(II) rapidly without intracellular transformation. In addition, when taken up into MR-1 cells, the intracellular MeHg and Hg(II) were proved to be hardly exported over time. In contrast, adsorbed mercury on cell surface was observed to be easily desorbed or remobilized. Moreover, inactivated MR-1 cells (starved and CCCP-treated) were still capable of taking up nonnegligible amounts of MeHg and Hg(II) over an extended period in the absence and presence of cysteine, suggesting that active metabolism may be not required for both MeHg and Hg(II) uptake. Our results provide an improved understanding of divalent mercury uptake by non-methylating/non-demethylating bacteria and highlight the possible broader involvement of these bacteria in mercury cycling in natural environments.
研究领域:
微生物学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）