ENERGY & FUELS
·
2024
·
IF 5.2
Siyuan Wang,Yunze Zhang,Jian Wang
Rationally designing highly active electrocatalysts for the oxygen reduction reaction (ORR) without relying on precious metals is critical for promoting the application of metal–air batteries and fuel cells. As a promising alternative to traditional Pt-group-based catalysts, transition-metal oxides (TMOs) with high corrosion resistivity and diverse structure configuration have exhibited great catalytic potential. However, the current favorable ORR performance of TMOs has often been achieved through their coupling with engineered carbons such as graphene and carbon nanotubes, which can obscure the intrinsic catalytic potential of TMOs. To promote TMO-based catalysts for ORR applications, comprehensively analyzing their catalytic properties and screening promising TMO-based parent materials is crucial. Herein to eliminate the research gap, 22 noble-metal-free TMOs (e.g., Co3O4, MnO, and Fe2O3) were benchmarked for ORR catalysis, with Pt/C and RuO2 as comparisons. Nb2O5 demonstrated the greatest potential as an ORR electrocatalyst among all of the studied TMOs, with higher specific activity surpassing that of Pt/C. In addition, it could achieve a larger peak power density than Pt/C in a more practical Zn–air battery setup, showing promise for applications. Regarding stability, most of the studied TMOs exhibited larger losses in limiting current densities than the degradation of half-wave potentials (from 0.65% to 7.54) after the 10,000 cycle accelerated degradation tests, pointing out the direction to improve their ORR stabilities.
研究领域:
电化学
·
材料科学
·
能源存储与转换
✓ 已验证
产品关联
DOI
高影响因子
RENEWABLE ENERGY
·
2021
·
IF 8.001
Jianmei Cen,Enjun Jiang,Yuqing Zhu,Zhenyu Chen,Panagiotis Tsiakaras,Pei Kang Shen
Herein, two novel electrocatalysts are simultaneously grown on Ni foam (NF) through a one-step hydrothermal method . The as-prepared Ru–MoO 3- x NF exhibits good performance for HER with low overpotentials of 12 mV at 10 mA cm −2 and 49 mV at 100 mA cm −2 , a low Tafel slope of 32.96 mV dec −1 , as well as an excellent durability at least lasting 17 h in alkaline media . The Fe 3 O 4 –NiFe LDH NF (layered double hydroxide nickel foam) ultrathin nanosheets electrode shows a low OER overpotential of 216 mV at 10 mA cm −2 and a small Tafel slope of 42.42 mV dec −1 . Moreover, a two-electrode water splitting device is fabricated with Ru–MoO 3- x NF as cathode and Fe 3 O 4 –NiFe LDH NF as anode, it only requires 1.46 V at 10 mA cm −2 and exhibits a long term durability without obvious loss of activity after continuously operating for 180 h. The superior catalytic behavior should be originated from the open heterostructure and oxygen vacancies with high intrinsic activity, abundant exposed active sites, and fast charge transfer. This work provides a new strategy to design heterostructure and transition metal oxides catalysts with improved catalytic activity and durability by a facile route for overall water splitting or other applications.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2019
·Vol. 9
·期 12
·1666
·
IF 4.034
Jien Yang,Qiong Zhang,Jinjin Xu,Hairui Liu,Ruiping Qin,Haifa Zhai,Songhua Chen,Mingjian Yuan
Despite the successful improvement in the power conversion efficiency (PCE) of perovskite solar cells (PSCs), the issue of instability is still a serious challenge for their commercial application. The issue of the PSCs mainly originates from the decomposition of the organic–inorganic hybrid perovskite materials, which will degrade upon humidity and suffer from the thermal environment. In addition, the charge transport layers also influence the stability of the whole devices. In this study, inorganic transport layers are utilized in an inverted structure of PSCs employing CsPbIBr2as light absorbent layer, in which nickel oxide (NiOx) and cerium oxide (CeOx) films are applied as the hole transport layer (HTL) and the electron transport layer (ETL), respectively. The inorganic transport layers are expected to protect the CsPbIBr2film from the contact of moisture and react with the metal electrode, thus preventing degradation. The PSC with all inorganic components, inorganic perovskite and inorganic transport layers demonstrates an initial PCE of 5.60% and retains 5.56% after 600 s in ambient air at maximum power point tracking.Keywords:inorganic perovskite;CsPbIBr2;metal oxide transport layers
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2022
·Vol. 27
·期 15
·4773
·
IF 4.927
Xin Yang,Tie Shu,Xianfeng Yang,Min Qiao,Dashuang Wang,Xinghua Li,Jinsong Rao,Zhaohui Liu,Yuxin Zhang,Pingan Yang,Kexin Yao
Reasonable structural design and composition control are the dominant factors for tuning the electromagnetic absorbing properties of materials. In this paper, microspheres composed of NiO, Ni, and Co3O4nanoparticles (NCMO) were successfully synthesized using a mild oxidation method. Benefiting from the multi-component composition and a unique microstructure, the RLminof CNMO can reach −46.8 dB at 17 GHz, with an effective absorption bandwidth of 4.1 GHz (13.9–18 GHz). The absorbing properties and the absorbing mechanism analysis showed that the microsphere-structured NCMO composed of multi-component nanoparticles enhanced the interface polarization, thereby improving the absorption performance. This research provides a new avenue for MOF-derived oxide materials with excellent electromagnetic wave absorbing properties.Keywords:electromagnetic wave absorption;MOFs;nanoparticles;metal oxide
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysts
·
2023
·Vol. 13
·期 5
·807
·
IF 3.9
Zhiping Zhao,Zhixia Wang,Yanbing Tong,Jinru Sun,Ming Ke,Weiyu Song
The search for inexpensive, environmentally friendly, and highly effective catalysts to activate C-H bonds in propane dehydrogenation (PDH) reactions is still a major challenge. Co-based catalysts have gained significant attention in recent years due to their excellent ability to activate C-H bonds and their high selectivity towards olefins, despite being a non-noble and environmentally unfriendly metal. However, further improvements are necessary for practical utilization, particularly in terms of activity and anti-carbon deposition capacity. In this study, we synthesized Al2O3nanorods with abundant pentacoordinated Al3+(Al3+penta) sites. The supported Co on the Al2O3nanorod (Co/Al2O3-NR) exhibited higher selectivity (>96% propylene selectivity) and stability (deactivation rate 0.15 h−1) compared to Co supported on an Al2O3nanosheet with fewer pentacoordinated Al3+sites. Various characterizations confirmed that Co(II) mainly exists as CoAl2O4rather than Co3O4in the form of Co/Al2O3-NR, which inhibits the reduction of Co(II) to Co0and accordingly improves catalyst stability.Keywords:propane dehydrogenation;metal oxide;alumina;spinel
研究领域:
化学工程
·
催化材料
✓ 已验证
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2016
·Vol. 3
·期 8
·1048-1057
·
IF 4.532
Hao Zhang,Xiaofeng Wang,Chengcheng Chen,Cuihua An,Yanan Xu,Yanying Dong,Qiuyu Zhang,Yijing Wang,Lifang Jiao,Huatang Yuan
We herein report a facile method for synthesizing a series of metal oxides from the mixture of oleylamine and metal nitrates with heating at 180 °C. Several diverse nanoparticles with various morphologies are gained expectedly: 16.5 nm Mn3O4 nano-capsules, 22 nm CoO nano-cubes, 35 nm NiO nano-flowers and 4 nm Fe3O4 quantum dots. This method is convenient for preparing the dispersed nanoparticles at mild reaction temperature with low-cost metal sources. As-prepared CoO nano-cubes are employed as the electrode material of a pseudocapacitor in terms of implementation. The specific capacitance reaches a stable level of 750 F g−1. This material also exhibits a superior performance in high rate capability and maintains an excellent stability during 9000 recycles. The asymmetric supercapacitor device with a maximum voltage of 1.7 V is fabricated using CoO nano-cubes as the positive and activated carbon as the negative electrode.
研究领域:
材料科学
·
纳米技术
·
电化学
✓ 已验证
DOI
高影响因子
Catalysis Science & Technology
·
2024
·
IF 4.4
Menghui Han,Fangyuan Cheng,Kui Xie
Porous single crystals (PSCs) are a novel class of solid-phase materials with tailored porosity. The long-range ordered lattice and interconnected pore structure in three dimensions enable them to minimize energy losses and maintain heightened catalytic activity and stability in electrochemical systems. In the process of electrocatalytic water splitting, transition metal oxides Fe2O3 and Co3O4 are regarded as highly promising catalytic materials for the oxygen evolution reaction (OER). Here, we employed a lattice reconstruction strategy to grow porous single crystals of Fe2O3 and Co3O4 through solid–solid phase transformation, utilizing FeS2 and CoS2 nano-octahedron single crystals as the parent crystals. PSC Fe2O3 and Co3O4 have large specific surface areas to provide enough electrocatalytic active sites while retaining the intrinsic properties of porous single crystals. Meanwhile, we quantitatively engineered Pt clusters/metal oxide interfaces on the surfaces of PSC Fe2O3 and Co3O4 to enhance the electrocatalytic performance. The PSC Pt/Co3O4 catalyst with lower overpotential (269 mV at 10 mA cm−2) exhibits optimal electrochemical performance in the OER, with no degradation observed within 25 hours. The structural consistency of these porous single crystal oxide catalysts, coupled with the construction of active interfaces, offers advantages in enhancing electrocatalytic activity and durability.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2019
·Vol. 150
·期 2
·322-331
·
IF 2.372
Wang Kaifeng,Liu Ya,Wu Wufeng,Chen Yu,Fang Lina,Li Wanbin,Ji Hongbing
Abstract In this study, Zr-MOF material (UiO-66) was modified with different metal oxides (CeO 2 , Ga 2 O 3 , and CoO) and employed in the conversion of cellulose to levulinic acid (LA) in aqueous medium. The research results showed that the introduction of the metal oxides increased the acid content of the catalysts, especially in medium-strong acid. The selectivity of LA was related to the type of metal oxide and the content of medium-strong acid. Due to the activity of Ga 2 O 3 and more medium-strong acid, the yield of LA reaches a maximum yield of 32.0 mol% at 513 K for 360 min when Ga 2 O 3 -UiO-66 was employed as the catalysts. The combination of metal oxide and UiO-66 enables the reaction to proceed, providing a new direction for the conversion of cellulose to LA in the aqueous phase. Graphic Abstract In this study, Zr-MOFs material (UiO-66) was modified with different metal oxides (CeO 2 , Ga 2 O 3 , and CoO) and employed in the conversion of cellulose to levulinic acid in aqueous medium. The results indicated that the addition of metal oxides changes the acidity of UiO-66, which improves the catalytic activity. The selectivity of LA was related to the type of metal oxide and the content of medium-strong acid.
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
Catalysts
·
2023
·Vol. 13
·期 7
·1031
·
IF 3.9
Jie Lin,Yihong Ding,Huile Jin,Tianbiao Zeng
Nickel, cobalt, and manganese oxides are easily obtainable non-noble metal catalysts for water splitting. However, the relationship between composition and catalysts’ performance still needs systematic studies. Herein, guided by theoretical calculations, a low overpotential, easily prepared Mn-doped Co3O4was deposited on graphite plates for water splitting. The 30% Mn-doped Co3O4(Co2.1Mn0.9O4) required the lowest overpotential for oxygen evolution reaction (OER), in which the Co2.1Mn0.9O4reached 20, 30, and 50 mA cm−2in the overpotentials of 425, 451, and 487 mV, respectively, with 90% IR compensation. Under overall water-splitting conditions, the current density reached 30 mA cm−2at an overpotential of 0.78 V without IR compensation. Charge density difference analysis illustrates that doped Mn provides electrons for O atoms, and that Mn doping also promotes the electron fluctuation of Co atoms. XPS analysis reveals that Mn-doping increases the chemical valence of the Co atom, and that the doped Mn atom also exhibits higher chemical valence than the Mn of Mn3O4, which is advantageous to boost the form of based-OOH* radical, then decrease the overpotential. Considering the particular simplicity of growing the Co2.1Mn0.9O4on graphite plates, this work is expected to provide a feasible way to develop the high-performance Co-Mn bimetallic oxide for water splitting.Keywords:water splitting;bimetallic oxides;Mn-doped Co3O4;DFT calculation
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2019
·
IF 4.507
Qingfeng Che,Minjiao Yang,Xianhua Wang,Xu Chen,Wei Chen,Qing Yang,Haiping Yang,Hanping Chen
Dual catalysts are proposed in this study to convert biomass pyrolysis vapors into aromatics. Metal oxides (CaO, Al 2 O 3 , and ZnO) and ZSM-5 were introduced into the catalytic upgrading process. In the pyrolysis process without ZSM-5, the addition of CaO effectively removed carboxylic organics and methoxyphenols, reducing the product yield with a hydrogen to carbon ratio of 0, and the size of phenol compounds. The addition of Al 2 O 3 greatly promoted the cracking of oxygenates with molecular weight above 109 g mol −1 , such as large-size methoxyphenols and sugars. It is found that the upgraded pyrolysis volatiles are more conducive to conversion for aromatics with a ZSM-5 catalyst. The addition of CaO increased the selectivity of xylene (15.9%), while Al 2 O 3 promoted the selectivity of toluene (18.3%). The highest yield of aromatics was obtained with CaO-ZSM-5 dual catalyst system, which was boosted by 6.14% compared to that of pure ZSM-5. To explore more effective methods for aromatics production, the arrangement of catalysts and temperature condition were investigated. Mixing CaO with biomass produced more aromatics than other methods, and the most suitable temperature for the formation of aromatic hydrocarbons was 600 °C.
研究领域:
能源科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Mingjie Li,Zebin Yu,Yanping Hou,Qing Liu,Lun Qian,Cuifang Lian,Xunzheng Rao,Xiaoting Yang
Ga 2 O 3 highlights the high energy band structure for redox reaction. However, information on noble metals and metal oxides deposited Ga 2 O 3 for contaminant elimination and the corresponding mechanisms is still lack. Here, metals and metal oxides deposited Ga 2 O 3 (labeled as M-P and MO-C; M = Ag, Pt, and Pd) were synthesized by photocatalytic and chemical deposition methods and confirmed with XRD and XPS. M-P and MO-C were applied in photocatalytic degradation of three typical contaminants: ciprofloxacin, ronidazole and rhodamine B. The ciprofloxacin and ronidazole degradation rates by Ag 2 O-C and rhodamine B degradation rate by Ag-P were 3.0, 2.7 and 2.4 times as high as those by pure Ga 2 O 3 . This research demonstrates that photocatalytic activities of M-P and MO-C are affected by the types and oxidation states of noble metals, as well as the target contaminants. Potentials of M or MO (E(M Φ ) or E(MO CB ), defined as work function of the metals or conduction band of the metal oxides) is the determining factor for both charge trapping and charge transfer abilities. The highest photocatalytic activity can be obtained when the E(M Φ ) or E(MO CB ) was kept at the level just beyond the single electron reduction potential of O 2 , such as Ag-P and Ag 2 O-C. Finally, the contaminants-specific photocatalytic activities were related to the different functional reactive species. Findings of this study provide important information for the rational design of M and MO deposited photocatalysts.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
RENEWABLE ENERGY
·
2022
·
IF 8.634
Shanshan Shao,Pengfei Zhang,Xianliang Xiang,Xiaohua Li,Huiyan Zhang
Ketonization of bagasse pyrolysis gas was performed over red mud-based oxides. The maximum yield of ketones in the catalytic conversion of bagasse pyrolysis gas over original red mud was 18.66% at 420 °C. To promote the oxidability of red mud and obtain a higher yield of ketones, the effect of metal oxides (CeO 2 , MnO 2 , TiO 2 , CaO, ZrO 2 ) loading and loading amount of CeO 2 on red mud on ketonization of bagasse pyrolysis gas were studied. The highest yield of ketones of 27.86% was obtained over red mud-based oxides with 40 wt% CeO 2 loading. The oxidability of the catalyst was enhanced greatly by the high loading of CeO 2 , leading to the peroxidation of acetone as the side reaction. To control the oxidability and cut costs, bimetallic oxides were loaded on red mud. The yield of ketones reached 30.12% over the composite red mud catalyst with the loading of 20 wt% CeO 2 and 20 wt% MnO 2 . The rough coating of MnO 2 on the surface of red mud was beneficial to the loading of CeO 2 , resulting in smaller and more uniform grains. This study provides the efficient utilization of red mud and biomass as solid wastes for high-valued chemicals and fuels.
研究领域:
能源与环境科学
·
催化化学
✓ 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）