JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2020
·Vol. 95
·期 9
·2403-2410
·
IF 2.75
Li Sun,Chuanliang Li,Hua Zhang,Binlin Dou,Wenxian Su,Lixin Zhang
BACKGROUND At present, much attention has been focused on the development of methane (CH 4 ) sensors due to a series of explosions and fires caused by CH 4 gas leakage. RESULTS Here, a CH 4 thermoelectric gas sensor (TGS) was fabricated by fixing 3D porous palladium/cobalt oxide (Pd/Co 3 O 4 ) catalyst on a commercial thermoelectric module. 3D porous Pd/Co 3 O 4 catalysts were prepared by a co-precipitation and gel-casting method. The pore structure in catalysts could be tailored only by adjusting the gel viscosity during the formation process. The protocol to tune the pore structure is facile and effective for the improvement of the activity of catalysts. By means of various techniques, the catalysts were characterized and then the possible catalytic mechanism was revealed. The CH 4 TGS based on the optimal Pd/Co 3 O 4 catalyst began to respond at 200 °C, following an obvious output voltage (Δ V ) of 5 mV. Enhancing the operating temperature to 240 °C, the value of Δ V reached to 31 mV and exhibited a linear relationship with CH 4 gas concentration. Meanwhile, the CH 4 TGS showed high sensitivity, repeatability and stability. CONCLUSION The easy and effective preparation method presented to prepare 3D porous Pd/Co 3 O 4 catalyst can provide an unique perspective on the development of 3D porous materials with excellent properties. It can be anticipated that the CH 4 TGS based on the 3D porous Pd/Co 3 O 4 catalyst will be a potential candidate for the detection of CH 4 gas in industrial settings. © 2020 Society of Chemical Industry
研究领域:
材料科学
·
化学工程
·
传感器技术
✓ 已验证
产品关联
DOI
高影响因子
NANOTECHNOLOGY
·
2022
·Vol. 33
·期 21
·210001
·
IF 3.953
Yiwen Chen,Junguo He,Peigen Jiang,Heliang Pang,Xuhui Hu,Jie Zhang,Wenjing Zhang
The growing chloramphenicol (CAP) in wastewater brought a serious threat to the activity of activated sludge and the spread of antibiotics resistance bacteria. In this study, a highly ordered nanoporous Co3O4 layer on Co foil through anodization was prepared as cathode for nitro-group reduction and electrodeposited with Pd particles for dechlorination to reduce CAP completely. After 3 h treatment, almost 100% of CAP was reduced. Co2+ ions in Co3O4 served as catalytic sites for electrons transfer to CAP through a redox circle Co2+–Co3+–Co2+, which triggered nitro-group reduction at first. With the presence of Pd particles, more atomic H* were generated for dechlorination, which increased 22% of reduction efficiency after 3 h treatment. Therefore, a better capacity was achieved by Pd/Co3O4 cathode (K = 0.0245 min−1, K is reaction constant) than by other cathodes such as Fe/Co3O4 (K = 0.0182 min−1), Cu/Co3O4 (K = 0.0164 min−1), and pure Co3O4 (K = 0.0106 min−1). From the proposed reaction pathway, the ultimate product was carbonyl-reduced AM (dechlorinated aromatic amine product of CAP) without antibacterial activity, which demonstrated this cathodic technology was a feasible way for wastewater pre-treatment.
研究领域:
环境科学
·
化学工程
·
生物医学工程
✓ 已验证
DOI
PubMed
高影响因子
ACTA PHYSICO-CHIMICA SINICA
·
2017
·Vol. 33
·期 7
·1453-1461
·
IF 0.767
LIU Jing-Wei,YANG Na-Ting,ZHU Yan
We report an efficient catalyst composed of ternary components prepared by inlaying Pd/Co3O4 nanoparticles in alkaline Al2O3 nanosheets for catalytic oxidation of methane. Pd/Co3O4 inlaid in alkaline Al2O3
exhibited a higher ability to break the C-H bond of methane than Pd/Co3O4 supported on SiO2, ZrO2, CeO2, and acidic or neutral Al2O3. Our results show more oxygen vacancies and higher amounts of surface adsorbed oxygen
on the surface of Pd/Co3O4/alkaline Al2O3 than on other catalysts, which is responsible for methane activation and conversion. Further, the Pd/Co3O4/alkaline Al2O3 catalyst can almost restore to its initial
value in the absence of water when 5% (volume fraction) vapor water was cut off, although a decrease in activity occurred when water vapor was introduced to the reaction system. Even under a condition similar to the exhaust of a lean-burn natural gas engine, the catalytic performance of the
Pd/Co3O4/alkaline Al2O3 catalyst is excellent, that is, methane could be completely converted when the sample temperature in the reaction atmosphere was ramped to 400°C.
研究领域:
化学
·
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2025
·
IF 17.7
Yuanjie Xu,Run Hou,Kunxiang Chi,Bo Liu,Zemin An,Lizhi Wu,Li Tan,Xupeng Zong,Yihu Dai,Zailai Xie,Yu Tang
Palladium-based catalysts have long been considered the benchmark for methane combustion; however, the authentic phase of catalytic active sites remains a subject of ongoing debate. Additionally, challenges like water-poisoning and long-term stability need to be addressed to advance catalyst performance. Herein, we investigate Pd on Co 3 O 4 nanorods as a highly effective catalyst for catalytic oxidation of methane, demonstrating long-term stability and water tolerance during a 100-h continuous operation at 350 °C. Comprehensive characterizations reveal the presence of an active Pd-oxygen vacancy (O v )-cobalt interface in Pd/Co 3 O 4 , which effectively adsorbs molecular O 2 . The absorbed oxygen species on this interface are activated and directly participate in methane combustion. Moreover, near-ambient pressure X-ray photoelectron spectroscopy demonstrates that Pd nanoparticles undergo a rapid phase transition and predominantly remain in the metallic state during the reaction. This behavior is attributed to the electronic metal-support interaction between Pd and Co 3 O 4 . Furthermore, in situ Fourier transformed infrared spectrum reveals that under reaction conditions, HCO 3 * species are formed initially and subsequently transformed into formate species, indicating that the formate pathway is the dominant mechanism for CH 4 oxidation.
研究领域:
催化
·
材料科学
·
环境化学
·
表面科学
✓ 已验证
产品关联
DOI
高影响因子
Scientific Reports
·
2017
·Vol. 7
·期 1
·1-9
·
IF 4.259
Qu Qing,Zhang Jian-Hua,Wang Jing,Li Qing-Yu,Xu Chang-Wei,Lu Xihong
Considerable efforts have been devoted recently to design and fabrication of high performance and low cost electrocatalysts for oxygen evolution reaction (OER). However, catalytic activity of current electrocatalysts is usually restricted by high onset potential and limited active sites. Herein, we fabricated three-dimensional (3D) highly ordered mesoporous Pd-Co 3 O 4 composite materials as excellent electrocatalysts for OER in alkaline solution with high activity and stability. Three-dimensional highly ordered mesoporous Co 3 O 4 material was firstly synthesized using mesoporous silica KIT-6 as hard template. Then, Pd-Co 3 O 4 nanomaterials were prepared by a simple reduction method. The as-prepared 3D mesoporous Pd-Co 3 O 4 catalysts have ordered mesoporous structure with a high surface area of 81.0 m 2 g −1 . Three-dimensional highly ordered mesoporous structure can facilitate diffusion and penetration of electrolyte and oxygen. Moreover, the catalysts can also keep catalyst particles in a well dispersed condition with more catalytic active sites. Electrochemical measurements reveal that the 3D mesoporous Pd-Co 3 O 4 catalysts exhibit superior performance in alkaline solution with low onset potential (0.415 V vs . SCE) and excellent long-duration cycling stability.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Desalination and Water Treatment
·
2024
·
IF 1
Qiuxiang Liu,Jinhui Fang,Sulin Ni,Shasha Tang,Zhiqiao He
A hybrid electrode comprised of Pd and Co 3 O 4 supported on Ni foam (Pd-Co 3 O 4 /Ni foam) was applied toward the dechlorination of 2,4-dichlorophenoxyacetic acid (2,4-D). The effects of the reaction condition, such as Co 3 O 4 and Pd loading, current density, initial concentration of 2,4-D, temperature and dissolved anions, on the electrochemical dechlorination process were investigated and interpreted based on an indirect reduction mechanism via active atomic H*. The optimal Pd and Co 3 O 4 loading were determined to be 0.47 and 0.51 mg/cm 2 , respectively. A highest current efficiency of 12.10% was obtained at a current density of 1.50 mA/cm 2 , an initial 2,4-D concentration of 50 mg/L and reaction temperature of 298 K, and the apparent activation energy of 2,4-D dechlorination by the Pd-Co 3 O 4 /Ni foam electrode was calculated to be 42.33 × 10 3 J/mol. In addition, dissolved anions such as S 2- , SO 3 2- and NO 3 - suppress the catalytic activity, whereas HCO 3 - and Cl - have a negligible effect on the reaction process. The Pd-Co 3 O 4 /Ni foam electrode can also be applied to the dechlorination of 2,4-D in natural water bodies as well as other chlorinated organic compounds, such as chlorophenols.
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）