NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 46
·期 18
·8739-8751
·
IF 3.925
Quansheng Wu,Songhua Zhou,Chengbing Fu,Jiesong Zhang,Bo Chen,Hongyan Pan,Qian Lin
For the mono-metal Pd based catalysts, the O–O bond in O2 and H2O2 is easily dissociated due to the higher energy sites of Pd, which decreases the selectivity and productivity of H2O2. To address this issue, non-noble metals M (M = Sn, Fe, Co, Ni) were doped into palladium precursors to create a series of yolk–shell structure bimetallic catalysts Pd–M@HCS (H = hollow; C = carbon; S = sphere) with Pd–M as the core and porous carbon as the shell. The results indicated that the catalyst Pd–M@HCS doped with Sn, Fe, Co, and Ni has a weak dissociation ability for O2, and both the adsorption and dissociation ability for H2 are improved. Of these catalysts, the catalyst Pd–Sn@HCS gives the best performance, which is benefited by the suitable Pd–Sn nanoparticle size and the best Pd2+/Pd0 ratio. The influence of the nPd/nSn ratio in the Pd–Sn@HCS system on catalyst performance was further explored, and the findings revealed that Pd–Sn@HCS had the best catalytic activity and stability when the nPd/nSn ratio was 2. The catalyst's H2 conversion, H2O2 selectivity, and productivity were 35%, 97%, and 3961 mmol gPd−1 h−1, respectively. After 10 cycles, the H2O2 productivity of this catalyst remained at 92.1%, which was greater than the H2O2 productivity of the typical Pd-based catalyst Pd/C, which stayed at 37% under the same conditions.
研究领域:
催化
·
化学工程
·
材料科学
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Ting He,Shuang Yao,Dejian Chen,Zhaoyun Sun,Xiaoyun Wang,Keyi Wang,Jiangwei Chen,Qingguo Li,Rizhi Chen,Yawei Wang,Zhaoliang Cui
Membrane oxygenator performs lung function in the Extra-corporeal Membrane Oxygenation (ECMO) system. In the clinical use, to ensure the balance of gas exchange of patient’s body, the gas-blood exchange membrane is required to possess CO 2 /O 2 selectivity, which is suggested to be in the range of 10-12. In our work, the molecular dynamics simulation results displayed that the amino-functionalized Zr-MOFs provides fast transport channels for CO 2 molecules because of the enhancement of the adsorption and diffusion ability for CO 2 . Therefore, we chose organic ligands with abundant CO 2 -philic groups to synthesize target amino-functionalized Zr-MOFs, and then dispersed them into medical-grade PDMS solution to study the separation performance of CO 2 /O 2 . On the basis of constructing anti-leakage coating layer, biomimetic gas channels were designed to increase the clearance rate of CO 2 . Experimental results exhibited that the CO 2 /O 2 selectivity of (NH 2 ) 2 -UiO-66/PDMS MMM was as high as 11.19, which was basically consistent with the simulation results. The obtained amino-functionalized Zr-MOF/PDMS coating layer displayed favorable biocompatibility and biosafety. Meanwhile, the construction of biomimetic channel solves the difficult problem of CO 2 removal in PMP membrane, which verifies the feasibility of applying porous materials to gas-blood exchange membranes in the ECMO system.
研究领域:
材料科学
·
生物医学工程
·
分子动力学模拟
·
膜技术
✓ 已验证
产品关联
DOI
高影响因子
Science Advances
·
2017
·Vol. 3
·期 6
·
IF 0
Pengwei Wang,Guofeng Zhao,Yu Wang,Yong Lu
Oxidative coupling of methane (OCM) is a promising method for the direct conversion of methane to ethene and ethane (C2 products). Among the catalysts reported previously, Mn2O3-Na2WO4/SiO2 showed the highest conversion and selectivity, but only at 800° to 900°C, which represents a substantial challenge for commercialization. We report a TiO2-doped Mn2O3-Na2WO4/SiO2 catalyst by using Ti-MWW zeolite as TiO2 dopant as well as SiO2 support, enabling OCM with 26% conversion and 76% C2-C3 selectivity at 720°C because of MnTiO3 formation. MnTiO3 triggers the low-temperature Mn2+↔Mn3+ cycle for O2 activation while working synergistically with Na2WO4 to selectively convert methane to C2-C3. We also prepared a practical Mn2O3-TiO2-Na2WO4/SiO2 catalyst in a ball mill. This catalyst can be transformed in situ into MnTiO3-Na2WO4/SiO2, yielding 22% conversion and 62% selectivity at 650°C. Our results will stimulate attempts to understand more fully the chemistry of MnTiO3-governed low-temperature activity, which might lead to commercial exploitation of a low-temperature OCM process.
研究领域:
化学工程
·
催化
·
能源化学
✓ 已验证
产品关联
DOI
PubMed
NEW JOURNAL OF CHEMISTRY
·
2019
·Vol. 44
·期 5
·1795-1805
·
IF 3.069
Hao Liu,Xiaodong Zhu,Rui Han,Yuxue Dai,Yuanling Sun,Yanna Lin,Dandan Gao,Xueying Wang,Chuannan Luo
Study of the degradation mechanism of the Cu2O/g-C3N4 p–n heterojunction is very challenging and important for the preparation and practical applications of the g-C3N4 photocatalyst in controlling water pollution. Therefore, the Cu2O/g-C3N4 p–n heterojunction was designed and prepared successfully and the mechanism of enhanced visible-light photocatalytic activity was proposed. The morphology and structure of the synthesized materials were characterized by using SEM, TEM, FT-IR and XPS. And the optical and electrical properties of the materials were studied by measuring DRS, the photocurrent density and the Mott–Schottky curve. The results showed that the g-C3N4 photocatalyst is coated on the surface of Cu2O to form a tight heterojunction, which facilitates the separation and migration of photogenerated carriers, and the quantum yield of the Cu2O/g-C3N4 composite photocatalyst was 3–7 times higher than that of the single component. It has been shown that the built-in electric field formed at the heterojunction interface can effectively separate photogenerated electrons and holes. The photocatalytic performance of the material was evaluated by the photocatalytic degradation of tetracycline (TC) under visible light. The maximum degradation rate of Cu2O/g-C3N4 for TC could reach over 90% in 90 min, and the degradation rate of the single component is more than doubled. Simultaneously, the TOC tests monitored the mineralization of TC up to 83.4%, and the active substances in the reaction process were determined to be ˙O2− and h+ through free radical trap experiments and ESR tests. This work shows that the construction of an internal electric field has greatly improved the photocatalytic performance of g-C3N4. The Cu2O/g-C3N4 p–n heterojunction has good degradation ability toward tetracycline and is a good tetracycline-type wastewater treatment material.
研究领域:
材料科学
·
环境科学
·
光化学
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2022
·
IF 5.876
Ning Zhang,Xiaofeng Ning,Jia Chen,Jianming Xue,Gongxuan Lu,Hongdeng Qiu
The development of TiO 2 -based composites with a broad light response and outstanding photocatalytic performance is very important for the removal of antibiotics. In this work, we prepared a series of new porous graphene (PG)/TiO 2 nanocomposites formed the different highly reactive interface within confined space via a partial combustion strategy using TiCl 4 as the Ti source. The as-prepared PG/TiO 2 exhibited the simultaneous effect of incredible adsorptivity and photodegradation performance toward tetracycline (TC) antibiotic under UV and visible light in contrast to conventional PG/TiO 2 , pure TiO 2 (P25) and PG. Optimization experiments showed that PG/TiO 2 -4% had the optimal removal performance among all the nanocomposites. The removal rate of TC reached up to 95.5%, which was 15% higher than that of I-PG/TiO 2 and 25% higher than that of P25 within 90 min. The results were credited to (1) the high specific surface area and porous structure of PG, (2) the broad light response range and rapid separation of h + and e − of PG/TiO 2 , and (3) the highly reactive interface between PG and TiO 2 nanoparticles . In addition, active radical trapping experiments indicated that ·O 2 − was crucial to the elimination of TC. This work showed the new potential of PG/TiO 2 nanocomposites for the enhanced photocatalytic performance.
研究领域:
环境科学
·
材料科学
·
纳米技术
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2024
·
IF 13
Zhiying Gao,Jingming Yao,Jitong Yan,Jun Sun,Congcong Du,Qiushi Dai,Yong Su,Jun Zhao,Jingzhao Chen,Xiaomei Li,Hui Li,Pan Zhang,Jun Ma,Hailong Qiu,Liqiang Zhang,Yongfu Tang,Jianyu Huang
Rechargeable aprotic lithium (Li)-oxygen battery (LOB) is a potential next-generation energy storage technology because of its high theoretical specific energy. However, the role of redox mediator on the oxide electrochemistry remains unclear. This is partly due to the intrinsic complexity of the battery chemistry and the lack of in-depth studies of oxygen electrodes at the atomic level by reliable techniques. Herein, cryo-transmission electron microscopy (cryo-TEM) is used to study how the redox mediator LiI affects the oxygen electrochemistry in LOBs. It is revealed that with or without LiI in the electrolyte, the discharge products are plate-like LiOH or toroidal Li 2 O 2 , respectively. The I 2 assists the decomposition of LiOH via the formation of LiIO 3 in the charge process. In addition, a LiI protective layer is formed on the Li anode surface by the shuttle of I 3 − , which inhibits the parasitic Li/electrolyte reaction and improves the cycle performance of the LOBs. The LOBs returned to 2e − oxygen reduction reaction (ORR) to produce Li 2 O 2 after the LiI in the electrolyte is consumed. This work provides new insight on the role of redox mediator on the complex electrochemistry in LOBs which may aid the design LOBs for practical applications.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF POROUS MATERIALS
·
2024
·
IF 2.5
Tang Yingying,Xia Yongfeng,Yao Dongxu,Zhu Ming,Zhao Jun,Zeng Yu-Ping
Thermal insulation materials must exhibit superior mechanical properties alongside exceptional thermal insulation conductivity. However, traditional porous ceramics often struggle to meet these dual requirements simultaneously. In high-entropy materials, the phonon scattering induced by lattice distortion effects can significantly reduce the thermal conductivity of ceramics, thus opening new avenues for the design of novel thermal insulation materials. Inspired by the high-entropy effect, this study employed solid-state reaction methods to synthesize (Ce 0.2 Zr 0.2 Ti 0.2 Sn 0.2 Ca 0.2 )O 2−δ (CZTSC) high-entropy ceramics at various temperatures, investigating their phase constituents, microstructural characteristics, and mechanical properties, while exploring the optimal sintering temperature. Additionally, a pore-forming agent method was utilized to fabricate monophasic CZTSC porous ceramics with different porosities at 1400 °C. Specifically, when the pore-forming agent content was 20 wt%, the sample exhibited an apparent porosity of 42.82%, with a low thermal conductivity of 0.57 W·m − 1 ·K − 1 , a low thermal diffusivity of 0.406 mm 2 ·s − 1 , and a relatively high compressive strength of 32.49 MPa. The current investigation underscores the promising prospects of porous CZTSC ceramics in the field of thermal insulation.
研究领域:
材料科学
·
热能工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Yue Tang,Xiaolin Pi,Huiying Li,Xueni Zhang,Lijun Luo,Fengzhi Jiang
This study presents the synthesis of highly active BiPO 4 /AgI/BC composite photocatalysts via a green, simple, and low-cost ambient temperature precipitation method. The electron transfer rate and visible-light responsiveness can be effectively enhanced by utilizing BiPO 4 compounded with the semiconductor AgI, which has a narrow bandgap and good visible-light responsiveness. Additionally, the introduction of biocarbon (BC) enhances the absorption and separation of photogenerated electrons and holes under visible light. Notably, the synthesized BP-AgI 0.6 -BC 5 % could remove 99.16 % and 99.7 % of EE2 and E2, respectively, at a concentration of 3 mg/L after 40 min of light exposure. The capture experiments and electron paramagnetic resonance spectroscopy reveal that the main active substance in the system is ·O 2 - , with BC playing a crucial role in enhancing the ·O 2 - concentration in the system. The findings from phytotoxicity and antimicrobial tests reveal that BP-AgI 0.6 -BC 5 % can efficiently degrade pollutants, producing degradation products that are substantially less toxic than the original pollutants. Moreover, it can remove more than 99.99 % of E. coli under both dark and light conditions, demonstrating excellent antimicrobial performance. Additionally, the photocatalytic mechanism and degradation pathway were examined in this study. Notably, the composite photocatalysts synthesized in this study achieved efficient degradation of EE2 and E2 under visible light conditions while exhibiting efficient bactericidal function. Furthermore, the room-temperature preparation method is conducive to industrial-scale production, highlighting a better prospect for practical applications.
研究领域:
环境科学
·
材料科学
·
生物学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Wenheng Hu,Huan Chen,Junjie Wang,Zhe Zhang,Zhengliang Zhang,Dawei Song,Yaqin Shi,Donghui Long,Yayun Zhang
Transforming alkanes into value-added light aromatics represents an promising strategy for maximizing the utility of fossil feedstocks. However, achieving highly selective aromatization reactions remains a formidable challenge. This study advocates for an alkane-O 2 coupling reaction strategy, which involves introducing a low-concentration O 2 atmosphere into the reaction system to facilitate the upgrading of alkanes to value-added aromatics over HZSM-5 zeolite catalyst. The investigation revealed that the abundant acidic sites on the zeolite facilitated alkane activation and subsequent C–C and C–H bond cleavage. Incorporating O 2 into the reaction generated oxygenated intermediates, significantly enhancing both the yield and selectivity of light aromatics compared to an inert atmosphere. Furthermore, the interaction of O 2 with coke bolstered the catalyst’s resistance to coking. Moreover, based on the in-situ FTIR results, a plausible alkane-O 2 coupling mechanism is proposed. These findings present a novel, effective, and environmentally benign approach for the highly selective aromatization of alkanes.
研究领域:
化学工程
·
催化
·
石油化学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2023
·
IF 6.6
Congcong Dang,Pu Feng,Sixian He,Liancheng Zhao,Aidang Shan,Ming Li,Lingti Kong,Liming Gao
The design of ultra-stable cathode materials of Li-O 2 batteries with excellent catalytic performance is very important and desirable. However, some problems such as sluggish electrochemical reaction kinetics and unwanted side reactions still remain challenging. Carbon materials own hierarchical porous structure which facilitates mass transport and accommodates discharge products but are not stable enough as cathode of Li-O 2 batteries. Here in, we fabricated a unique NiCo bimetallic phosphide combined with carbon nanotube heterostructure (abbreviated as NiCoP/CNT) by hydrothermal method. Density functional theory (abbreviated as DFT) calculation demonstrates that bimetallic phosphide NiCoP/CNT delivered much better electrical conductivity, greater adsorption to reactants, and more electron transfer with discharge products Li 2 O 2 , compared to monometallic phosphides CoP and Ni 2 P. Therefore, NiCoP/CNT based cathode displayed low overpotential of 0.87 V at current of 100 mA g −1 with a fixed specific capacity of 1000 mAh g −1 and run steadily over 150 cycles under high current of 500 mA g −1 with a fixed specific capacity of 1000 mAh g −1 . Furthermore, Ex-situ X-ray Photoelectron Spectroscopy and in-situ differential electrochemical mass spectroscopy proved the existence of intermediate products Li 2-x O 2 . This approach provides a reference for designing and synthesis of bimetallic cathode in Li-O 2 batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2016
·
IF 4.803
Jingpeng Wang,Chunyu Du,Xing Xu,Xiaoshu He,Geping Yin,Yulin Ma,Pengjian Zuo,Xinqun Cheng,Yunzhi Gao
A facile high-temperature solid phase approach is employed to coat lithium phosphorus oxynitride (LiPON) layer on the concentration gradient Li[Ni 0.73 Co 0.12 Mn 0.15 ]O 2 material with Ni-rich core and Ni-poor surface. X-ray diffraction, scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy demonstrate that LiPON forms an even coating with ∼4 nm of thickness on the surface without destroying the bulk structure of Li[Ni 0.73 Co 0.12 Mn 0.15 ]O 2 material. The LiPON-coated concentration gradient Li[Ni 0.73 Co 0.12 Mn 0.15 ]O 2 material exhibits a capacity retention of 87.3% at 25 °C after 1000 cycles and 89.9% at 55 °C after 250 cycles, which is 36.1% and 17.2% higher than that of pristine Li[Ni 0.73 Co 0.12 Mn 0.15 ]O 2 material, respectively, under the same operating conditions. This significantly improved cycling performance is ascribed to the noncrystalline LiPON layer on the surface, which provides a reliable interface protection. The LiPON coating is an effective approach to enhancing the electrochemical performance of electrode materials for lithium ion batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
ACTA PHYSICO-CHIMICA SINICA
·
2014
·Vol. 30
·期 1
·150-156
·
IF 0.886
YANG Bing-Jian,WANG Hong,Li Lei,HUANG Bo-Wen,LIAO Xiao-Zhen,HE Yu-Shi,MA Zi-Feng
The development of low-cost and effective electrocatalysts for air electrodes is critical for practical applications of lithium/oxygen batteries. In the present work, phenanthroline (phen) was used as a ligand to prepare a Co(phen)2 complex. The Co(phen)2 complex
was coated on BP2000 and then heat treated at 600, 700, 800, and 900 , to obtain carbon-supported Co-N (Co-N/C) catalysts. The catalytic activities in oxygen reduction reaction/oxygen evolution reaction (ORR/OER) of the prepared catalysts were measured and compared with those of a typical
carbon-supported cobalt tetramethoxyphenylporphyrin (CoTMPP/C) catalyst. The influence of the calcination temperature on the composition and structure of the Co-N/C catalysts was investigated. Electrochemical tests showed that the Co-N/C catalysts prepared at 700 and 800 gave better performances,
comparable to that of the CoTMPP/C catalyst. The superior electrochemical performance of the prepared Co-N/C catalysts and the low cost of the phenanthroline chelating agent make Co-N/C a promising cheap catalyst for lithium/oxygen batteries.
研究领域:
材料科学
·
电化学
·
能源存储与转换
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）