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您的检索式:作者名="M.Reddy BENJARAM"
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| 1 | Rare earth metal doped CeO_2-based catalytic materials for diesel soot oxidation at lower temperatures显示文摘In this work, the influence of trivalent rare-earth dopants(Sm and La) on the structure-activity properties of CeO2 was thoroughly studied for diesel soot oxidation. For this, an optimized 40% of Sm and La was incorporated into the CeO2 using a facile coprecipitation method from ultra-high dilute aqueous solutions. A systematic physicochemical characterization was carried out using X-ray diffraction(XRD), transmission electron microscopy(TEM), Brumauer-Emmett-teller method(BET) surface area, X-ray photoelectron spectroscopy(XPS), Raman, and H2-temperature programmed reduction(TPR) techniques. The soot oxidation efficiency of the catalysts was investigated using a thermogravimetric method. The XRD results suggested the formation of nanocrystalline single phase CeO2-Sm2O3 and CeO2-La2O3 solid solutions. The Sm- and La-doped CeO2 materials exhibited smaller crystallite size and higher BET surface area compared with the pure CeO2. Owing to the difference in the oxidation states of the dopants(Sm3+ and La3+) and the Ce4+, a number of oxygen vacancies were generated in CeO2-Sm2O3 and CeO2-La2O3 samples. The H2-TPR studies evidenced the improved reducible nature of the CeO2-Sm2O3 and CeO2-La2O3 samples compared with the CeO2. It was found that the addition of Sm and La to the CeO2 outstandingly enhanced its catalytic efficiency for the oxidation of diesel soot. The observed 50% soot conversion temperatures for the CeO2-Sm2O3, CeO2-La2O3 and CeO2 were ~790, 843 and 864 K(loose contact), respectively, and similar activity order was also found under the tight contact condition. The high soot oxidation efficacy of the CeO2-Sm2O3 sample was attributed to numerous catalytically favourable properties, like smaller crystallite size, larger surface area, abundant oxygen vacancies, and superior reducible nature. | A.Rangaswamy Putla Sudarsanam Benjaram M.Reddy | 2015 | Journal of Rare Earths2015,33,11: | 21 |
| 2 | 非负载和氧化铝负载的纳米CeO_2-ZrO_2和CeO_2-Te_2O_3固溶体催化CO氧化(英文)显示文摘Ceria-zirconia(CZ)and ceria-terbia(CT)and alumina-supported ceria-zirconia(CZA)and ceria-terbia(CTA)solid solutions were synthesized by coprecipitation and deposition precipitation methods,respectively.Structural characteristics and catalytic activity of the synthesized samples have been investigated using X-ray diffraction(XRD),high resolution transmission electron microscopy(HRTEM),X-ray photoelectron spectroscopy(XPS),Raman spectroscopy(RS),and Brunauer-Emmett-Teller(BET)surface area measurements.To evaluate the catalytic properties,total oxygen storage capacity and CO oxidation activity measurements were carried out.The XRD analyses revealed the formation of Ce0.75Zr0.25O2 phase for CZ and Ce0.5Zr0.5O2 and Ce0.6Zr0.4O2 phases for CZA samples,respectively.While the formation of only Ce0.8Tb0.2O2-δphase was noted for both CT and CTA samples.All the supported and unsupported samples adopted a fluorite-type structure and exhibited cell parameters with respect to Vegard's rule.The HRTEM results indicated well-dispersed particles of the size around 5 nm.The RS measurements suggested the presence of oxygen vacancies due to defective structure formation.The XPS studies revealed the presence of cerium in both Ce 4+ and Ce 3+ oxidation states in different proportions.It was found that CO oxidation for CTA occurs at very much lower temperature than CT,CZ,and CZA samples.Details of these findings by correlating with the structural characterization studies are consolidated. | M.Reddy BENJARAM Thrimurthulu GODE Lakshmi KATTA | 2011 | 催化学报2011,32,5: | 3 |
| 3 | Synthesis of coumarins catalyzed by ecofriendly W/ZrO2 solid acid catalyst显示文摘 | Benjaram M.Reddy Vangala R.Reddy Giridhar D | | 0,,: | 1 |
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