CRYSTENGCOMM
·
2021
·Vol. 23
·期 43
·7602-7614
·
IF 3.545
Chao Feng,Gaoyan Xiong,Yaping Li,Qianqian Gao,Yuan Pan,Zhaoyang Fei,Yanpeng Li,Yukun Lu,Chenguang Liu,Yunqi Liu
Determining the effect of crystal facets on reaction performance is essential for designing an efficient propane oxidation catalyst. Herein, α-MnO2 nanowires with exposed (110), (211), (310) and (200) facets were proposed, and their crystal facet-dependent reactivity to propane oxidation was investigated. The resultant α-MnO2 nanowires with predominantly exposed (110) facets showed the maximum propane oxidation activity (T90 = 262.1 °C), oxidation rate, and turnover frequency (at 230 °C), and high stability during the oxidation of propane. In situ diffuse reflectance infrared Fourier transform spectroscopy revealed that the oxidation to form carboxylates is the decisive step; therefore, the production of reactive oxygen species is very important. The results from density of states computations revealed that the lowest electron energy was present in the (110) facet, which helps in the generation of reactive oxygen species and the regulation of the surface valence of Mn. The characterization and calculation results indicated that the (110) facets are conducive to forming oxygen vacancies, which allowed the activation and adsorption of O2 and propane, resulting in significantly enhanced propane oxidation activity. Apart from offering new insights about the structure–activity relationship of α-MnO2 with different facets exposed for short-chain volatile oxidation reactions, this study proposes a technique that can be used for improving other manganese-based catalyst oxidation systems.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Lidong Sun,Nian Li,Shudong Zhang,Xinling Yu,Cui Liu,Yongqiang Zhou,Shuai Han,Wenbo Wang,Zhenyang Wang
Porous carbon composite electrodes have attracted extensive attention due to their excellent electrochemical performance toward energy storage applications. In this work, hierarchical nitrogen-containing porous carbon (HNPC) and α-MnO 2 nanowires composite electrode is prepared through a template method. The as-prepared composite electrode, characterized as one-dimensional nanowires inserted into three-dimensional interconnected porous structures, exhibits high specific capacitance of 204.6 F g −1 at 1 A g −1 and excellent cycling stability (97.2% remains after 5000 cycles). Moreover, the fabricated asymmetric supercapacitor based on HNPC//HNPC/MnO 2 achieves a wide working voltage window of 1.8 V and a high energy density up to 30.1 Wh kg −1 at a power density of 900.0 W kg −1 . The results indicate that the HNPC/MnO 2 composite electrodes with excellent electrochemical performance have promising perspective in supercapacitor applications.
研究领域:
材料科学
·
能源存储与转换
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2023
·Vol. 13
·期 3
·588
·
IF 3.9
Haiou Zhang,Yixin Zhang,Huikang Song,Yan Cui,Yingying Xue,Cai-e Wu,Chao Pan,Jingxin Xu,Jian Qiu,Leilei Xu,Mindong Chen
As a toxic pollutant, carbon monoxide (CO) usually causes harmful effects on human health. Therefore, the thermally catalytic oxidation of CO has received extensive attention in recent years. The CuO-based catalysts have been widely investigated due to their availability. In this study, a series of transition metal oxides (Fe2O3, Co3O4and NiO) promoted CuO-based catalysts supported on the α-MnO2nanowire catalysts were prepared by the deposition precipitation method for catalytic CO oxidation reactions. The effects of the loaded transition metal type, the loading amount, and the calcination temperature on the catalytic performances were systematically investigated. Further catalyst characterization showed that the CuO/α-MnO2catalyst modified with 3 wt% Co3O4and calcined at 400 °C performed the highest CO catalytic activity (T90= 75 °C) among the investigated catalysts. It was supposed that the loading of the Co3O4dopant not only increased the content of oxygen vacancies in the catalyst but also increased the specific surface area and pore volume of the CuO/α-MnO2nanowire catalyst, which would further enhance the catalytic activity. The CuO/α-MnO2catalyst modified with 3 wt% NiO and calcined at 400 °C exhibited the highest surface adsorbed oxygen content and the best normalized reaction rate, but the specific surface area limited its activity. Therefore, the appropriate loading of the Co3O4modifier could greatly enhance the activity of CuO/α-MnO2. This research could provide a reference method for constructing efficient low-temperature CO oxidation catalysts.Keywords:transition metal oxides;CuO-based catalysts;Co3O4modification;α-MnO2nanowire;catalytic oxidation of CO
研究领域:
催化
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2020
·
IF 16.683
Yingguang Zhang,Muyan Wu,Yifei Wang,Yu Ho Kwok,Wending Pan,Wai Szeto,Haibao Huang,Dennis Y.C. Leung
The particular role of fluorine (F) doping in the photocatalytic activity of nanocrystalline titanium dioxide (TiO 2 ) towards toluene degradation was systematically studied. TiO 2 nanosheet catalysts doped with different amounts of F − (denoted by F-TiO 2 ) were synthesized by hydrothermal method. For comparison, calcination was performed on the catalyst to remove F - . The photocatalytic oxidation (PCO) of toluene over F-TiO 2 was found to be much higher than those of TiO 2 and commercial P25 under the irradiation of vacuum ultraviolet (VUV) light, with a high toluene degradation efficiency of about 90 %. Moreover, the toluene degradation efficiency increased to 96 % with the addition of only 1 wt.% α-MnO 2 nanowires, and the residual ozone (O 3 ) in the system can be completely eliminated. In addition, four different substrates were explored for catalyst coating to facilitate the operation and minimize catalyst loading, which can provide a promising strategy for practical volatile organic compounds (VOCs) abatement in industrial applications.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）