FUEL
·
2023
·
IF 7.4
Fanggang Zhang,Sheng Su,Juan Wang
Aiming to achieve efficient utilization of high-energy–density fuels in the promising portable power systems, self-sustained combustion of n-decane over Co 3 O 4 -based catalysts in a narrow quartz reactor was investigated. Chemiluminescence, gas chromatography and various physicochemical characterization methods were used in this study. The evidences suggest that Co 3 O 4 -based catalysts can significantly reduce the ignition temperature and broaden the flammability limits of n-decane. The heat release stored in the catalyst bed can help improve the flame stability, delay the flame extinction, and achieve auto-ignition without forced heating. Besides, great promotion of the catalytic performance of Co 3 O 4 spinel is achieved by doping with 6 wt% PdO. PdO/Co 3 O 4 catalysts exhibit higher activity and enhanced ability in effectual resistance toward deactivate than pure Co 3 O 4 . Furthermore, the coupling of heterogeneous and homogeneous reactions of n-decane has been analyzed. It can be revealed that both the adsorbed and gaseous OH* radicals play greatly different roles when using different catalysts. These findings promote the use of heavy hydrocarbon fuels for energy supply and contribute to designing efficient Co 3 O 4 -based catalysts rationally.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
2022
·
IF 3.428
Yao Tian,Chunmei Zeng,Shiyu Yang,Yang Luo,Lunhong Ai,Jing Jiang
Development of efficient and economical non-precious metal catalysts for dehydrogenation of ammonia borane is an important way to store and release hydrogen. Vacancy-engineered defective catalysts with modulated electronic structure allow ideal adsorption and dissociation of reactant molecules for the optimized catalytic activity. In this study, we report a facile synthesis of cobalt-defective Co 3 O 4 (V Co -Co 3 O 4 ) nanocatalyst by the calcination of layered cobalt glycerate as a key precursor. The stacked cobalt-oxygen sheets and interlayer bound glycerate anions in a layered structure are favorable for introducing cation vacancy during calcination process. The obtained V co -Co 3 O 4 exhibits outstanding catalytic activity for the hydrolysis of ammonia borane, along with a high hydrogen production rate of 934 mL min −1 g Cat -1 and a low activation energy of 32.65 kJ mol −1 . The catalytic performance of the V Co -Co 3 O 4 catalyst can be well maintained for consecutive five cycles. The current study establishes a new example of cation vacancy strategy to facilitate the hydrolysis of ammonia borane for hydrogen generation.
研究领域:
材料科学
·
催化化学
·
能源存储与转换
✓ 已验证
DOI
高影响因子
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
·
2019
·Vol. 2019
·期 24
·2933-2939
·
IF 2.578
Xuefeng Hu,Zeshu Zhang,Yibo Zhang,Liwei Sun,Heyuan Tian,Xiangguang Yang
Graphical A Pt/Co 3 O 4 catalyst was prepared by the galvanic displacement method, which exhibited excellent catalytic activity for toluene combustion (T 90 = 150 °C at GHSV = 60 000 mL g –1 h – 1 ) and outstanding stability reflected in a continuous 100 h on-stream toluene combustion lifetime experiment without loss in catalytic activity. Catalytic combustion has become one of the most economical, feasible and effective tools for the abatement of VOCs. However, it is difficult to prepare supported Pt catalysts possessing both excellent catalytic activity and stability by traditional preparation methods, such as incipient-wetness impregnation method and nanoparticle loading method. In this work, we prepared Pt/Co 3 O 4 catalyst with high catalytic activity and stability for the catalytic combustion of toluene by galvanic displacement method. As comparing, additional reference samples were prepared using incipient-wetness impregnation method and nanoparticle loading method, respectively. All of the samples were characterized by XRD, TEM, H 2 -TPR, O 2 -TPD and XPS techniques. The catalyst prepared by galvanic displacement method exhibited the best catalytic activity with the temperature of 90 % toluene conversion about 150 °C (T 90 = 150 °C) and outstanding stability reflected in a continuous 100 h on-stream toluene combustion lifetime experiment without catalytic activity decline at the GHSV = 60 000 mL g –1 h –1 compared to which prepared by traditional methods. These results are attributed to the excellent oxygen mobility, the high surface chemisorbed oxygen species concentration and the strong interaction between Pt and support Co 3 O 4 . Therefore, our work provided a universal strategy for designing high-efficiency and stable catalyst for the abatement of VOCs at low temperature.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Li Wang,Wende Hu,Zhou Shang,Xiaoming Cao,Yun Guo,Jiayi Li,Qiyuan Gu,Ke Li,Xiaobo Li
Enhancement in oxidation performance of Co 3 O 4 -based catalysts can be achieved by regulating K, and the promotion effects were strongly depended on the amount and existing state of K. Only the surface Co substituted by optimum amount of K (CoK 2 with K/Co mole ratio of 1.56 × 10 -2 ), unexpectedly high activities could be achieved. The specific activity of CoK 2 were 20 and 2.7 times higher than that of Co 3 O 4 for CO oxidation and CH 4 combustion. However, the excess K in the form of carbonate or nitrate deactivated the active sites, so the performance against K amount behaved as a volcano curve. Based upon the electronic and structural modification of K, the electron density of Co and O simultaneously decreased which weakened CO adsorption strength and improved the C H bond activation. Since efficiency in various pollutants removal, CoK 2 could be considered as a promising candidate for noble metal catalysts.
研究领域:
化学
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2019
·
IF 7.723
Jing Wang,Tianqinji Qi,Zhibin Li,Wei She,Xuewei Li,Jingfang Li,Pengfei Yan,Weizuo Li,Guangming Li
Three novel N-doped carbon supported Co/Co 3 O 4 catalysts, namely, Co@CN- hmta , Co@CN- larg and Co-Co 3 O 4 @CN- bipy , with sheet-, worm-, honeycomb-like morphologies respectively, have been fabricated by the pyrolysis of well-defined coordination polymers (CPs). Upon the as-prepared catalysts were applied for the reaction of N-alkylation of nitroarenes with ethanol, a direct two-step tandem reaction is realized, in which the Co@CN- hmta delivers 100% conversion/selectivity of N-ethylaniline/N , N-diethylaniline from the direct N-alkylation of nitroarenes with ethanol. The kinetic studies were conducted to confirm that the N-alkylation of aniline with ethanol is the rate-determining step in the two-step tandem reaction. The SEM/EDX, XRD, Raman, TEM, XPS, and CO 2 -TPD characterization results have revealed that sizes and dispersion of metallic Co, amount of structural defects and surface Lewis basicity towards three catalysts can be tuned by changing the structures of Co-based CPs designed by different organic linkers, which may also help to understand the preparation of industrial catalysts on a molecular level. The optimized Co@CN- hmta catalyst is easily recycled by using the external magnet for successive reuses without any loss in both activity and selectivity. To the best of our knowledge, this is the first carbon-nitrogen species supported Co/Co 3 O 4 catalysts derived from the CPs, which could effectively catalyzed the N-alkylation of nitroarenes with ethanol to produce the secondary amines and/or tertiary amines. This low-cost, recyclable and easy scale-up N-doped carbon supported catalyst may be of potential application in various heterogeneous catalytic reactions.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2021
·
IF 5.909
Hailu Fu,Jilei Lin,Shuang Cao,Bosheng Chen,Renhua Huang,Hao Chen,Tao Ding,Pengfei Sun,Ligang Luo
A series of cobalt-based catalysts (Co 3 O 4 , Mn/Co 3 O 4 , K-Co 3 O 4, and K-Mn/Co 3 O 4 ) were prepared for toluene catalytic combustion and anti-K poisoning experiments. Co 3 O 4 catalyst has exhibited good performance in toluene oxidation , but it has poor anti-K poisoning performance. The Mn/Co 3 O 4 catalyst has shown excellent low-temperature catalytic activity , good resistance to K poisoning at T 90 of 226 °C, and achieved a complete toluene conversion at about 235 °C; the activity after the addition of K slightly reduced at T 90 of 237 °C. A series of characterizations indicated that adding Mn can effectively promote the Co 2+ ↔Co 3+ cycle, increase the Co 3+ content on the catalyst surface, and enhance the redox performance of the catalyst. On the other hand, MnO x intercepts K species and generates Mn-O-K, blocking most of the poisonous effects of K on cobalt oxide , thereby protecting the active species (Co 3+ and surface-adsorbed oxygen) and acidic sites on the Co 3 O 4 surface. Finally, GC-MS and in-situ infrared characterization were adopted to investigate the reaction mechanism of the catalysts. Two reaction paths of the Co 3 O 4 catalyst may co-occur. Still, the reaction path of the Mn/Co 3 O 4 catalyst is relatively simple; that is, the chemically adsorbed toluene molecules are oxidized through surface-active oxygen, after which various intermediate by-products are formed successively. Finally, they are completely degraded into CO 2 .
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
FUEL
·
2025
·
IF 7.5
Jingting He,Kun Yang,Guisheng Qi,Zonglin Yi,Yujing Guo,Qiang Guo
Electrocatalytic nitrate reduction reaction (NO 3 RR) represents a promising approach for regulating the global nitrogen cycle and serves as a crucial complementary method for ammonia synthesis. However, NO 3 RR is a complex reduction process involving the transfer of eight electrons and nine protons. Therefore, it is difficult for catalysts with a single catalytic site to maintain an advantage throughout the NO 3 RR process. Consequently, the fabrication of catalysts with synergistic effects to achieve both high efficiency and selectivity remains a formidable challenge. Herein, a simple precipitation-calcination process was employed to successfully introduce boron (B) and nickel (Ni) elements into Co 3 O 4 (B/Ni-Co 3 O 4 ) simultaneously. Impressively, the as-prepared B/Ni-Co 3 O 4 catalyst exhibited a remarkable NH 3 yield of 17.2 mg·h −1 ·mg cat −1 and a high FE of 97.2 % at −0.5 V relative to the reversible hydrogen electrode (RHE). Density functional theory (DFT) computations uncovered a cooperative effect between B and Ni dopants, specifically: B doping exhibited appreciable efficacy in NO 3 – adsorption, and the Ni dopant showed notable activity in promoting the conversion of NO 2 − . Further DFT calculations identified the *NO → *NOH step as rate-determining and revealed that B-Ni co-doping diminishes its thermodynamic energy barrier. Concurrently, experimental measurements showed that such co-doping lowers the onset potential to −0.06 V vs. RHE. This dual doping strategy significantly accelerates the electroreduction of NO 3 − to NH 3 .
研究领域:
电化学
·
催化化学
·
材料科学
·
环境化学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2024
·
IF 20.2
Hongchun Sun,Cui Dong,Chao Feng,Hui Wang,Zhenping Qu
Co 3 O 4 catalysts possess high activity in selective catalytic oxidation of NH 3 (NH 3 -SCO), but the low N 2 selectivity hinders their potential application. To enhance N 2 selectivity, the chemical bonded Nb-O-Co catalyst by the deposition of Nb species onto Co 3 O 4 (Nb/Co 3 O 4 -0.03) is constructed. It shows 100 % NH 3 conversion and 82 % N 2 selectivity at 180°C, and the N 2 selectivity is 2.2-fold higher than that of Co 3 O 4 (38 %). The failure of enhancement in N 2 selectivity for physically mixed Co 3 O 4 and NbO x (NbO x |Co 3 O 4 -0.03) further indicates the crucial role of chemical bonded Nb-O-Co in enhancing N 2 selectivity. In situ diffuse reflectance infrared Fourier transform spectra and NH 3 temperature-programmed desorption results show the formation of new NH 3 adsorption sites. Importantly, intermediates NO - stabled on Nb/Co 3 O 4 -0.03 tends to react with -NH 2 to produce N 2 through internal selective catalytic reduction (iSCR). This work offers insights into enhancing the N 2 selectivity in NH 3 -SCO and advances understanding of iSCR mechanism.
研究领域:
化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2018
·
IF 2.179
Shi-Yuan Zhang,Yuan-Yuan Yang,Yue-Qing Zheng,Hong-Lin Zhu
Electrocatalytic reduction of CO 2 to useful fuels or chemicals is a promising path for carbon recycling. In this study, a novel mixed-metallic MOF [Ag 4 Co 2 (pyz)PDC 4 ][Ag 2 Co(pyz) 2 PDC 2 ] was synthesized, and it transformed into Ag doped Co 3 O 4 catalyst, which exhibits excellent electro-catalytic performance for reduction of CO 2 in water to syngas (H 2 + CO). The as-prepared Ag/Co 3 O 4 material exhibits a high selectivity of CO in 0.1 M KHCO 3 aqueous solution (CO 2 saturated) with the corresponding faradaic efficiency up to 55.6%. Compared with the Ag/Co 3 O 4 electrode, the maximum faradaic efficiency (FE) of CO of pure Co 3 O 4 is 21.3% at − 1.8 V vs. SCE. The results show that the presence of Ag can improve the efficiency of CO significantly, thereby inhibiting the production of H 2 . The stability of the samples can be maintained for more than 10 h at − 1.8 V vs. SCE. The ratio of production between H 2 and CO can be controlled by varying the potential values.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2023
·
IF 4.2
Chuang Li,Senqing Fan,Jiaojiao Chen,Yu Chen,Mingxia Yang,Jiaxin Meng,Haijie Qing,Yangchao Liu,Zeyi Xiao
An electrocatalytic membrane structured reactor with a stainless steel membrane as the Co3O4 catalyst carrier (Co3O4@SS EMSR) has been fabricated for benzyl alcohol oxidation coupled with hydrogen evolution. The structural characterization shows that the Co3O4 catalyst with the average size of 20 nm has been immobilized in the membrane pores. The electrochemical characterization indicates that the electrochemical active surface area can be increased and faster electron transfer can be achieved. During the process of benzyl alcohol oxidation coupled with hydrogen evolution by Co3O4@SS EMSR via flow-through mode, the benzyl alcohol conversion of 99% and the selectivity of benzoic acid of 97.7% with the Faraday efficiency of 95.9% for benzoic acid production can be achieved. The hydrogen production from the experiments is approximately consistent with the theoretically calculated hydrogen production, and a Faraday efficiency of 99% for hydrogen evolution can be achieved. The cell voltage during benzyl alcohol oxidation coupled with hydrogen evolution under the flow-through mode is reduced by 850 mV, and energy consumption is reduced by 2.03 kWh NmH2–3 under the condition of a current density of 2.6 mA cm–2, compared with those of hydrogen production by water electrolysis with the oxygen evolution reaction.
研究领域:
化学工程
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2024
·Vol. 12
·期 28
·17463-17470
·
IF 10.7
Shiqiang Sun,Guoling Li,Shanhui Zhu,Wenhao Meng,Leilei Xu,Jinlong Jiang,Fagen Wang,Xingyun Li
Precise defect engineering of metal oxide catalysts holds great importance for improving catalytic oxidation reactions. In this work, a judicious strategy by doping and partially de-doping of Cr atoms was orchestrated to produce a defect-containing Co3O4 catalyst. The co-existence of the remaining Cr dopant and some metal vacancies could synergistically contribute to the distortion of the crystal structure, Co–O bond activation, generation of abundant active oxygen species and enhancement of oxygen reactivity. Consequently, the catalytic performance for the methane oxidation reaction was significantly boosted, with a methane conversion rate normalized by the specific surface area of 0.114 μmol m−2 s−1, 1.41 times that of the pure Co3O4 catalyst at a reaction temperature of 295 °C. This work provides a viable methodology for improving Co3O4 catalysts for efficient methane oxidation.
研究领域:
催化
·
材料科学
·
环境化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Chemistry
·
2018
·
IF 3.886
Dan Li,Qiying Liu,Changhui Zhu,Haiyong Wang,Chunhua Cui,Chenguang Wang,Longlong Ma
2,5-dimethyfuran (DMF), which is produced from 5-hydroxymethyfurfural (HMF) by hydrodeoxygenation (HDO), is a high quality fuel due to the high heating value, the high octane number and the suitable boiling point. Selective hydrogenation of HMF into liquid fuel DMF has been widely researched. In this paper, Co 3 O 4 catalyst was prepared by co-precipitation and was reduced at different temperatures to form Co–CoO x catalysts. The characterization of catalysts was tested by XRD , TEM, XPS , TPR, BET and NH 3 -TPD. Co–CoO x possessed a high amount of Co metal and CoO x acidic sites, wherein Co worked as the active hydrogenation sites and CoO x acted as the acid promoter to facilitate the selective HDO of HMF to DMF. The synergistic effect of Co–CoO x is the key for HDO of HMF, obtaining 83.3% of DMF yield at 170 °C, 12 h and the reduction temperature of 400 °C. This method not only saves the catalyst cost, but also promotes the utilization of biomass energy.
研究领域:
能源化学
·
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）