Preparation of nanocrystalline Na_2ZrO_3 for high-temperature CO_2 acceptors:chemistry and mechanism

Nanocrystalline Na2ZrO3 was demonstrated as a promising acceptor for CO2 capture at elevated temperatures. The mechanism of nanocrystalline Na2ZrO3 formation from the soft-chemistry route is elucidated by varying precursors, preparation methods, and calciantion temperatures, combining detailed characterizations by X-ray diffraction （XRD） and scanning electron microscope （SEM） at different steps in the process. The results revealed that the drying method such as spraying drying and simple evaporation-drying did not influence the final product prop- erties. However both Na and Zr precursors had remarkable influences on the Na2ZrO3 formation. The solid reaction of Na intermediate and nanocrystalline ZrO2 in the calcination was identified as the key step for the Na2ZrO3 formation, where the formation of molten phase Na intermediate was found to be crucial to facilitate the solid reaction. We provided principles for rational design of the chemistry for the Na2ZrO3 formation where the formation of Na intermediate with low melting points is essential. Pure nanocrystalline Na2ZrO3 can be synthesized from a mixture containing sodium nitrate and zirconoxy citrate via the formation of NaNO3 with low melting point. However, it is not possible to form pure nanocrystalline Na2ZrO3 at relatively low temperatures from the mixtures of NaAc/ZrO（NO3）2 or NaCA/ZrOC12 due to the formation of Na2CO3 and NaC1 with high melting points.

Synthesis and Structural Characterizations of Ternary Iron(Ⅱ)Mixed Ligand Complex:Low Cost Materialsas a Precursor for Preparation of Nanometric Fe_(2)O_(3) Oxide

The reaction of the ligands,ethylenediaminetetraacetic acid terasodium salt(Na 4EDTA)and N—N heterocyclic diamines like2,2’-bipyridine(bipy)with iron(Ⅱ)sulfate with 1∶2∶2 stoichiometric ratios form the mononuclear ternary complex of formulae,[Fe_(2)(EDTA)(bipy)2]at pH~7.The FTIR and Raman laser spectra of the iron(Ⅱ)complex show that 2,2’-bipyridine is present asa bidentate ligand and the ethylenediaminetetraacetic acid terasodium salt as monodentate carboxylate anion.The electronic spectra and magnetic moments data suggest the six coordination number.It has two iron(Ⅱ)centers in octahedral environments,which are interlinked by carboxylato-O atoms of ethylenediaminetetraacetate and by nitrogen atoms of the two 2,2-bipyridine ligands in a chelating mode.Thermal analysis study show thatiron(Ⅱ)complex containing EDTA and 2,2’-bipyridine on its thermalde composition form the corresponding Fe_(2)O_(3) oxide in nano size at the temperature range~475℃.The iron(Ⅱ)complex was performed as a convenient low cost precursor for the preparation of Fe_(2)O_(3) nanoparticles by the the thermal decomposition method.The iron(Ⅲ)oxide composition has been discussedusing FTIR,X-ray diffraction(XRD),transmission electron microscopy(TEM)and energy-dispersive X-ray spectroscopy(EDX).

高硫石油焦的碱催化煅烧联合超声氧化深度脱硫（英文）

采用两段脱硫方法对高硫石油焦进行深度脱硫,并对碱催化煅烧和超声辅助化学氧化阶段的工艺条件进行优化。结果表明,在Na2CO3添加量25%、900℃恒温2 h、粒径80μm、升温速率1℃/min条件下,石油焦脱硫率达到最大值为67. 2%。在氧化温度80℃、HNO_3浓度65 wt%、反应12 h、粒径80μm、液固比20 mL/g的条件下,超声辅助氧化法的总脱硫率达到93. 5%。在碱催化煅烧过程中,噻吩硫和亚砜的去除率分别为73. 4%和59. 8%,经后续的超声波辅助氧化后,噻吩硫和亚砜的总去除率分别为93. 6%和93. 3%。同时,通过XPS分析了高硫石油焦在碱催化煅烧和超声辅助氧化工段中的脱硫机理。