Author
Jin-bing Li
Bio: Jin-bing Li is an academic researcher from Sinopec. The author has contributed to research in topics: X-ray absorption fine structure & Adsorption. The author has an hindex of 1, co-authored 2 publications receiving 28 citations.
Papers
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TL;DR: In this paper, the effect of calcination temperature on the structure and catalytic performance of Co3O4/SiO2 catalysts for CO oxidation has been investigated and shown to be significant.
Abstract: Co3O4/SiO2 catalysts for CO oxidation were prepared by conventional incipient wetness impregnation followed by calcination at various temperatures. Their structures were characterized with X-ray diffraction (XRD), laser Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction (TPR) and X-ray absorption fine structure (XAFS) spectroscopy. Both XRD and Raman spectroscopy only detect the existence of Co3O4 crystallites in all catalysts. However, XPS results indicate that excess Co2+ ions are present on the surface of Co3O4 in Co3O4(200)/SiO2 as compared with bulk Co3O4. Meanwhile, TPR results suggest the presence of surface oxygen vacancies on Co3O4 in Co3O4(200)/SiO2, and XAFS results demonstrate that Co3O4 in Co3O4(200)/SiO2 contains excess Co2+. Increasing calcination temperature results in oxidation of excess Co2+ and the decrease of the concentration of surface oxygen vacancies, consequently the formation of stoichiometric Co3O4 on supported catalysts. Among all Co3O4/SiO2 catalysts, Co3O4(200)/SiO2 exhibits the best catalytic performance towards CO oxidation, demonstrating that excess Co2+ and surface oxygen vacancies can enhance the catalytic activity of Co3O4 towards CO oxidation. These results nicely demonstrate the effect of calcination temperature on the structure and catalytic performance towards CO oxidation of silica-supported Co3O4 catalysts and highlight the important role of surface oxygen vacancies on Co3O4.
36 citations
TL;DR: In this article, an unexpected formation of nitrite/nitrate surface species on Ag/Pt(110)-(1×2) bimetallic surfaces was observed, then decompose at elevated temperatures to form N2.
Abstract: NO adsorption on Ag/Pt(110)-(1×2) bimetallic surfaces at room temperature was investigated by means of Auger electron spectroscopy, X-ray photoelectron spectroscopy and thermal desorption spectroscopy. An unexpected formation of nitrite/nitrate surface species on Ag/Pt(110)-(1×2) bimetallic surfaces is observed, then decompose at elevated temperatures to form N2. However, such nitrite/nitrate surface species do not form on clean Pt(110) and Ag-Pt alloy surfaces upon NO exposure at room temperature. The formation of nitrite/nitrate surface species on Ag/Pt(110)-(1×2) bimetallic surfaces is attributed to high reactivity of highly coordination-unsaturated Ag clusters and the synergetic effect between Ag clusters and Pt substrate.
TL;DR: In this paper , a semi-crystalline poly(arylene ether ketone) PEM with ultra-densely sulfonic-acid-functionalized pendants linked by flexible alkyl chains is presented, where x represents the molar ratio of the novel monomer containing multiple phenyl side chain to the bisfluoride monomers.
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TL;DR: In this article, a functionalized oxygen-deficient Co 3 O 4 nanorods were used for supercapacitor and water splitting dual applications, achieving a significantly high specific capacitance of 739 F ǫ g − 1 and an ultralow overpotential of 275 mV at 10mV at OER with ultralong stability of over 300 mV.
274 citations
TL;DR: In this paper, three kinds of Co3O4 catalysts with different concentrations of surface oxygen vacancies were successfully synthesized through a solvothermal and subsequent thermolysis method, and they exhibited the best performance for formaldehyde oxidation due to their larger specific surface area, higher low-temperature reducibility and abundant active surface oxygen species.
251 citations
TL;DR: In this article, a DFT+U calculation was performed on the electronic structure and catalytic performance of a β-MnO2 catalyst for the oxygen reduction reaction (ORR) with different numbers and extents of OVs.
Abstract: Oxygen vacancies (OVs) are important for changing the geometric and electronic structures as well as the chemical properties of MnO2. In this study, we performed a DFT+U calculation on the electronic structure and catalytic performance of a β-MnO2 catalyst for the oxygen reduction reaction (ORR) with different numbers and extents of OVs. Comparing those results with the experimental XRD analysis, we determined that OVs produce a new crystalline phase of β-MnO2. Changes in the electronic structure (Bader charges, band structure, partial density of states, local density of states, and frontier molecular orbital), proton insertion, and oxygen adsorption in β-MnO2 (110) were investigated as a function of the bulk OVs. The results show that a moderate concentration of bulk OVs reduced the band gap, increased the Fermi and HOMO levels of the MnO2 (or MnOOH), and elongated the O–O bond of the adsorbed O2 and coadsorbed O2 with H. These changes substantially increase the conductivity of MnO2 for the catalysis of ...
221 citations
TL;DR: In this article, Urchin-like Co3O4 microspheres have been obtained through a two-step hydrothermal method followed by a post-calcination process and show a unique hollow structure with mesoporous nanosheets on their surface.
Abstract: Urchin-like Co3O4 microspheres have been obtained through a two-step hydrothermal method followed by a post-calcination process and show a unique hollow structure with mesoporous nanosheets on their surface. Oxygen vacancies on the ultrathin nanosheets were introduced by annealing treatment, inducing a local built-in electric field to promote the migration of Li ions by Coulomb force during cycling and leading to a superior electrochemical performance for lithium-ion batteries. The electrodes containing urchin-like mesoporous hollow Co3O4 microspheres delivered a high discharge capacity of 2164.1 mA h g−1 at 0.05 A g−1 after 100 cycles. Even at a higher current density of 1.0 A g−1, a remarkable discharge capacity of 1307.9 mA h g−1 after 1000 cycles could still be achieved.
219 citations
TL;DR: In this paper, the involvement of suprafacial and intrafacial oxygen species in catalytic combustion of methane over the (100) faceted cobalt spinel was systematically examined as a function of temperature and CH4 conversion (XCH4).
Abstract: Involvement of suprafacial and intrafacial oxygen species in catalytic combustion of methane over the (100) faceted cobalt spinel was systematically examined as a function of temperature and CH4 conversion (XCH4). The clear-cut Co3O4 nanocubes of uniform size were synthesized using a hydrothermal method and characterized with XRD, RS, HR-TEM, XRF, TPSR (CH4/16/18O2), and SSITKA (CH4/16/18O2) techniques. The experimental results were corroborated by first-principles thermodynamic and DFT+U molecular modeling, providing a rational framework for a detailed understanding of the origin of a different redox comportment of the catalyst with the varying temperature and its mechanistic implications. Three temperature/conversion stages of the methane oxidation reaction were distinguished, depending on involvement of the adsorbed or lattice oxygen and the redox state of the catalyst. A stoichiometric (100) surface region (300 °C < T < 450 °C, XCH4 < 25%) is featured by the dominant suprafacial (Langmuir–Hinshelwood)...
100 citations