助剂改性FeOOH及其煤直接液化催化活性

采用共沉淀法分别引入Si、Al、La、Ca、Mg、Zr、Cu、Ni和Co 9种助剂元素对Fe OOH催化剂改性,借助BET、XRD、SEM手段表征各助剂对催化剂微观结构、晶相和形貌的影响,在0.5 L高压釜内测试各催化剂对神东煤的直接液化催化活性。结果表明,引入Si、Al、Ca、Zr、Ni、Co能改善催化剂比表面积和分散度,分别提高煤液化油收率0.7~2.7个百分点;Ni和Co为最优助剂,Mg没有促进作用,Cu、La降低了油收率。研究表明,Al、Ca、Zr是通过结构支撑改善催化剂的织构性质,促进生成易于转化为活性相的小晶粒γ-Fe OOH,Ni、Co主要起到电子型助剂作用,通过强化对氢气的活化,促进煤的转化,提高油收率。     

助剂对Ni/SiO2催化剂1,4-丁炔二醇加氢性能的影响

通过分步浸渍法在Ni/SiO 2催化剂中分别引入Zn、Cu、La、Mo、Co金属助剂,结合N 2物理吸附-脱附、XRD、H 2-TPR和NH 3-TPD等表征手段研究金属助剂对1,4-丁炔二醇加氢性能的影响。结果发现,Mo的引入使Ni/SiO 2催化剂的初始活性大幅增加,但反应2 h后活性下降,归因于催化剂表面酸中心使催化剂积炭失活;引入Cu、La及Co后的催化剂活性较低,推测是由于催化剂表面产生强吸附氢物种,不利于1,4-丁炔二醇加氢反应进行;与其他样品相比,Zn的引入使催化剂保持了Ni/SiO 2催化剂高的1,4-丁炔二醇加氢活性,同时可有效降低产物中2-羟基四氢呋喃副产物含量,提高目标产物1,4-丁二醇收率。     

硅/铝改性FeOOH及其煤直接液化催化性能

采用沉淀-空气氧化法分别制备了以Si含量2%~7%(物质的量比,下同),Al含量2%~15%改性的FeOOH催化剂.采用BET,XRD,SEM和TG-DTG等表征手段,考察了Si和Al改性催化剂的微观结构和形貌,并在500mL高压釜内评估了对神东煤的直接液化催化性能.结果表明,随Si量增加,催化剂由α-FeOOH和γ-FeOOH转化为无定型六线水合氧化铁,Si超过5%时发生团聚;Si不影响FeOOH各物种的热分解温度,但会降低失重率.Al能持续改善催化剂织构性质,并取代Fe形成FexAl1-xOOH,使各物种分解向高温偏移.Si和Al改性FeOOH催化剂的煤转化率不变,但能降低氢耗,促进沥青向油转化,提高油收率;Si为5%,Al为10%~15%时催化性能分别达到最优.     

第二金属对Ni/Al2O3·SiO2催化重整制氢的影响

本文以尿素作为沉淀剂采用沉积-沉降法制备出NiM/Al2O3.SiO2（M=La,Co,Zr和Y）催化剂。研究第二金属La,Co,Zr和Y的添加对Ni/Al2O3.SiO2催化剂上乙醇水蒸气重整制氢性能的影响,结果表明：Co、La或Y能有效的提高Ni/Al2O3.SiO2催化剂的性能。TPR得出：添加La、Y或Zr能促使活性组分分散到载体中。XPS得出：La,Co的添加能极大地提高还原后催化剂表面单质Ni的含量。     

铜仁松桃道坨锰矿的地球化学特征研究

本文通过对道坨矿区锰矿的研究,得出各元素之间的相关性;矿体中的Mn、Ca、Mg、烧失量与Si、K、Na、Al、Ti呈明显的负相关,而烧失量与Ca、Mg呈明显的正相关关系,Si、K、Na、Al、Ti相互两两间呈明显的正相关关系,锰与微量元素间缺乏明显的相关关系,仅与V、Ni、Cu、Bi、Se、Ba这六种元素呈负相关关系,元素比值Ti/Fe、Ni/Cu、Ni/Zn、Cu/Zn无论在页岩中还是在矿体中,其范围和平均值非常接近。本次研究还发现,矿体中Ti/Co的平均值小于100,Fe/Co的平均值小于1000,Co/Ni、Co/Cu的平均值都大于1的关系,进而可作为本区和邻区开展同类矿床勘查时的重要参考依据。     

La改性Cu/Zn/Al催化剂的制备及其催化纤维素液化性能

采用共沉淀法制备了不同La含量改性Cu/Zn/Al的催化剂,通过热重分析(TG/DTG)、X射线衍射(XRD)、比表面积测定(BET)、H₂程序升温还原(H₂-TPR)等表征手段对改性催化剂进行评价,分析结果表明,La助剂能够促进活性组分在载体表面的分散,很好地维持了催化剂的孔结构,适量助剂La的添加可促进CuO、ZnO两相间相互融合,增加活性中心的分散度,使CuO更加易于还原,但过多的La含量会使催化剂的性能发生改变,导致催化剂的活性降低。在超临界甲醇中使用La改性Cu/Zn/Al催化剂催化液化微晶纤维素,发现添加少量的La可有效地提高催化液化效果,相较于为添加助剂的Cu/Zn/Al催化剂,MCC转化率与醇类收率都得到了明显的提高。通过GC-MS分析,可以得到液化产物主要有醇类、酯类、酮类、醛类、烷烃等物质,添加助剂后提高了醇类产物的选择性。设置单因素实验,可知改性后Cu_1.2Zn_4.8Al_1.9La_0.1催化剂的最佳反应条件为:反应温度320℃,反应时间75min,催化剂用量75%。     

改性Ni/La_2O_3催化剂抑制甘油蒸汽重整制氢中的甲烷化反应

为抑制Ni/La_2O_3催化剂在丙三醇重整反应中的甲烷化反应,提高氢气选择性,制备了Ni-M/La_2O_3改性催化剂(M为Mg、Al、Cu、Ca、K、Na等金属),并在固定床反应器中进行催化剂活性评价。结果表明,在催化剂中以氢氧化物形式存在金属助剂(Ca、K、Na)对于甲烷化反应的抑制要优于以氧化物形式存在的(Mg、Al、Cu)。碱性环境下,载体金属镧主要以La(OH)_3和La CO_3OH的形式存在,抑制了La_2O_2CO_3和La_2Ni O_4的生成,从而降低了其对甲烷化反应的催化活性。XRD检测说明了关于抑制甲烷化反应的机理,即Na助剂的添加抑制了La_2Ni O_4的产生,降低了甲烷化反应的选择性。     

Mg、La助剂在镍基甲烷化催化剂中的协同作用

采用浸渍法制备Ni/Al2O3、La-Ni/Al2O3、Mg-Ni/Al2O3和Mg-La-Ni/Al2O3催化剂,讨论Mg和Ni两种助剂的协同作用,通过N2低温吸附、H2-TPR、XRD和SEM等表征方法对4种催化剂进行分析。结果表明,La助剂有利于削弱NiO与载体间的相互作用,降低催化剂中γ-NiO含量,但形成活性较低的α-NiO。Mg能够抑制催化剂中NiAl2O4尖晶石的形成,但Mg的添加会导致催化剂孔道堵塞,使NiO在催化剂表面团聚。Mg能够与NiO形成固溶体,在Mg的协同作用下,可抑制La-Ni/Al2O3催化剂中α-NiO的生成。La能够促进NiO分散,克服Mg-Ni/Al2O3催化剂孔道堵塞的缺陷。活性评价实验结果表明,添加不同助剂的催化剂在不同温度区域的活性不同,La-Ni/Al2O3催化剂低温活性较好,Mg-Ni/Al2O3催化剂高温活性较好,而在Mg和La两种助剂的协同作用下,Mg-La-Ni/Al2O3催化剂活性最高。     

等离子体制备稀土金属掺杂甲烷干气重整Ni/Mg/Al催化剂

采用冷等离子体炬技术制备了以水滑石为前驱体的Ni/Mg/Al催化剂,考察了La和Ce助剂的添加对催化剂结构及其对CH_4和CO_2重整催化性能的影响。利用XRD、BET、XPS及TG对催化剂进行了表征和性能测试。结果表明:冷等离子体炬能快速分解Ni/Mg/Al水滑石前驱体,生成具有介孔特性的水镁石相Mg(Ni,Al)O固溶体,并生成Ni0晶粒。在温度700℃、空速30 000 m L/(h·gcat)、V(CH4)∶V(CO2)=4∶6时,CH_4和CO_2的转化率分别为76.6%和61.8%。助剂Ce的添加增加了晶格氧的含量,促进了催化剂表面碳物种的消除,CH_4和CO_2的转化率分别提高了4%和7%。La的加入,抑制了Ni0晶粒的团聚,增加了Ni0的分散度,与未添加La的催化剂相比,非活性碳的生成量减少70%,表现出良好的抗积炭性能。     

等离子体制备稀土金属掺杂甲烷干气重整Ni/Mg/Al催化剂研究

采用冷等离子体炬技术制备了以水滑石为前驱体的Ni/Mg/Al催化剂,考察了La和Ce助剂的添加对催化剂结构及其对CH4和CO2重整催化性能的影响。利用XRD、BET、XPS及TG对催化剂进行了表征和性能测试。结果表明：冷等离子体炬能快速分解Ni/Mg/Al水滑石前驱体,生成具有介孔特性的水镁石相Mg(Ni,Al)O固溶体,并生成Ni0晶粒。在温度700℃,空速30000mL/(h·gcat), V（CH4）：V（CO2）=4：6的条件下,CH4和CO2的转化率分别为76%和61.8%。助剂Ce的添加增加了晶格氧,促进催化剂表面碳物种的消除,CH4和CO2的转化率分别提高了5%和7%。La的加入,抑制了Ni晶粒的团聚,增加了Ni的分散度,与未添加La的催化剂相比非活性碳的生成量减少70%,表现出良好的抗积炭性能。     

Hydrogen Production from Glycerol Over Nickel Catalysts Supported on Al<Subscript>2</Subscript>O<Subscript>3</Subscript> Modified by Mg,Zr, Ce or La

Hydrogen production from glycerol reforming in liquid (aqueous phase reforming, APR) and vapor (steam reforming SR) phase over alumina-supported nickel catalysts modified with Ce, Mg, Zr and La was studied. Characterization of catalysts by temperature programmed reduction and XPS analyses revealed important structural effects: (i) the intercalation of Mg between nickel and alumina that inhibited the alumina incorporation to nickel phases, (ii) the close contact between Ni and Zr phases and, (iii) the close surface interaction of La and Ce ions with NiO phases. The catalytic activity of the samples studied in this work clearly indicated the different catalyst functionalities necessary to carry out aqueous-phase and vapor-phase steam reforming of glycerol. For aqueous phase reforming of glycerol, the addition of Ce, La and Zr to Ni/Al₂O₃ improves the initial glycerol conversions obtained over the Ni/Al₂O₃ supported catalyst. It is suggested that the differences in catalytic activities are related with geometric effects caused by the decoration of Ni phases by Ce and La or by the close interaction between Ni and Zr. In spite that nickel catalysts showed high APR activities at initial times on stream, all samples showed, independently of support, important deactivation rates that deactivate the catalysts after few hours under operation. Catalysts characterization after APR showed the oxidation of the active metallic Ni during reaction as the main cause of the observed deactivation. In the case of the glycerol steam reforming in vapor phase, the use of Ce, La, Mg and Zr as promoters of Ni based catalysts increases the hydrogen selectivity. Differences in activity were explained in terms of enhancement in: surface nickel concentration (Mg), capacity to activate steam (Zr) and stability of nickel phases under reaction conditions (Ce and La).     

Solvent-free liquid phase oxidation of benzyl alcohol to benzaldehyde by molecular oxygen using non-noble transition metal containing hydrotalcite-like solid catalysts

Performance of Co–Al, Ni–Al, Cu–Al, Zn–Cu–Al, Mg–Fe, Co–Fe, Ni–Fe, Mn–Cr, Co–Cr, Ni–Cr, Zn–Cr and Cu–Cr hydrotalcite-like solid catalysts has been evaluated for the liquid phase oxidation of benzyl alcohol to benzaldehyde using molecular oxygen as an oxidizing agent in the absence of any solvent. The Mn and Cu containing hydrotalcite-like solids show good catalytic activity in the oxidation and hence these are promising catalysts for the solvent-free oxidation reaction.     

γ-Al2O3负载铜锌氧化物催化剂的N2O催化分解性能

以γ-Al₂O₃为载体,采用共浸渍法合成了负载量为35%（以CuO与ZnO总质量计）的CuZn金属氧化物催化剂,分别考察了金属助剂（Co、Ni,、Mg、Fe、Mn、Ba和Ce）对催化剂的影响。采用XRD、BET和H₂-TPR等方法对制备的催化剂进行表征,在微反装置上对催化剂的N₂O催化分解活性进行评价。结果表明,合成的CuZn氧化物催化剂均具有CuxZn_1-xAl₂O₄的类Co₃O₄尖晶石结构;加入金属助剂使催化剂的比表面积不同程度得到提高,催化剂的N₂O催化分解反应活性不仅与Cu³⁺还原为Cu²⁺的温度有关,还与晶粒尺度大小和催化剂比表面积等有关;其中,含金属助剂Ni的催化剂具有相对较高的N2O催化分解反应活性,其N₂O完全转化温度为567 ℃。除含金属助剂Ba催化剂以外,加入其他金属助剂有利于N₂O催化分解反应进行。     

Total oxidation of selected mono-carbon VOCs over hydrotalcite originated metal oxide catalysts

Hydrotalcite originated Cu–Mg–Al, Co–Mg–Al and Cu–Co–Mg–Al oxide systems were tested as catalysts for the total oxidation of mono-carbon VOCs (methane, methanol, and formic acid). Both calcination temperature of the hydrotalcite precursors as well as doping of the catalysts with potassium promoter influenced their catalytic activity. Increased calcination temperature, which resulted in a decrease of the surface area of the samples and formation of the spinel phases, activated the Co–Mg–Al catalyst, while the opposite effect was observed for the Cu–Mg–Al and Cu–Co–Mg–Al catalysts. On the other hand doping of the catalysts with potassium promoter significantly activated the Cu–Mg–Al and Cu–Co–Mg–Al catalysts in the processes of methanol and formic acid conversion, while only slightly influenced the catalytic performance of the Co–Mg–Al sample.     

NiFe2O4-M金属陶瓷惰性阳极成分设计的热力学分析

NiFe2O4-M金属陶瓷惰性阳极由氧化物陶瓷相和金属相组成.多数美国专利认为Fe,Ni,Cu,Co,Ti,Cr,Mn,Al,Pd,Ag,V,Zr,Y,La,Ta,Nb,Sc,Hf,Ca,Sn,Zn等21种金属均适合作为上述阳极的金属相成分.但文中的热力学详细分析计算结果表明:在上述前8种金属中,仅有Cu,Ni 2种适...     

Trace metal distribution in fractions of solvent-refined coal by ICP-OES and implications regarding metal speciation

Separations of Amax solvent-refined coal according to its acid/base/neutral components and by selective elution from a silica column (SESC) to yield nine fractions have been carried-out. After ashing with H₂O₂-H₂SO₄, twenty metals (Mg, Al, P, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Mo, Cd, Sr, Zr, W, Hg and Ba) were analysed by Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES). A majority of elements (Zn, Cd, Hg, Cr, Mo, W, and Fe) were found concentrated in the acid fraction while Co, Ni and Cu preferred the neutral and base fraction. In the step gradient SESC fractions, the greatest concentration of metal was found in fractions that had been characterized as enriched with phenols.     

Memory effect-enhanced catalytic ozonation of aqueous phenol and oxalic acid over supported Cu catalysts derived from hydrotalcite

Mg/Al supported metal (Fe, Co, Ni and Cu) oxide catalysts were prepared by co-precipitation of hydrotalcite-like clay materials as precursors, calcined, and used for the ozonation reaction of phenol and oxalic acid. The reaction was carried out using the catalyst and aqueous solution of phenol or oxalic acid in an O₃/O₂ mixed gas-flow at 20 °C. In the ozonation of phenol, the combination of ozone and supported metal oxide catalysts was effective for the removal of total organic carbon (TOC). Also in the ozonation of oxalic acid as the main TOC component, Cu/Mg/Al catalysts showed the highest activity, followed by Ni/Mg/Al catalyst, while both Fe/Mg/Al and Co/Mg/Al catalysts were not active. Leaching of Cu and Ni, probably due to the chelation of metals by oxalic acid, was significantly observed at the beginning of the reaction. However the metal leaching disappeared at the end of the reaction possibly due to the entire consumption of oxalic acid during the reaction. The best result of oxalic acid mineralization was observed over Cu/Mg/Al catalyst calcined at 600 °C, on which least leaching of the metal was detected. Moreover, a “memory effect” of hydrotalcite accelerated the mineralization of oxalic acid over the Cu/Mg/Al catalyst; oxalate anions were captured and decomposed in the reconstituted hydrotalcite interlayer space on the surface of the Cu/Mg/Al catalyst, resulting in a remarkable enhancement in the catalytic activity of the ozonation.     

臭氧催化分解的研究

研究了多种单组分和双组分金属氧化物对臭氧催化分解的活性,单组分时催化分解活性次序为：Co＞Mn≈Ni＞Cr＞Fe＞Zn＞Mg＞Cu＞Ag＞Sn ＞Pb＞U＞Cd＞Al＞Si≈Bi≈Ce≈CaCO₃≈La＞Na。实验结果表明,几种双组分金属氧化物的催化分解活性主要由较高活性的金属氧化物所决定,并与两组分的比例有关。实验还表明,催化剂的催化分解活性与制备催化剂时的灼烧温度和时间有关,催化剂前驱体采用硝酸盐时比较合理的灼烧条件为：500 ℃,4 h。     

Oil agglomeration as a pretreatment for coal liquefaction

Laboratory experiments demonstrated that a variety of distillate coal liquefaction recycle oils were satisfactory agents for cleaning Illinois no. 6 bituminous coal by oil agglomeration. Ash rejection up to 41% with 98% organic recovery was attained with conventionally cleaned coal, and ash rejection up to 67% with 90% organic recovery with run-of-mine coal. Agglomerates of > 1 mm average diameter were produced under a variety of conditions. Similar results were obtained in the scaled-up production of 268 kg of agglomerates. Oils with lower hydrogen aromaticities and higher hydrogen contents performed better than more aromatic oils. Fe, Ti and Mg were selectively enriched in the ash of the product coal, while Ca, Si, and Al were selectively rejected. The mineral pyrite was rejected only ≈ 30–40% as extensively as the bulk of the ashforming minerals. The coal cleaned by oil agglomeration performed similarly to the feed coal in batch donor liquefaction tests. In continuous hydroliquefaction tests, run-of-mine coal cleaned by oil agglomeration performed substantially better than coal cleaned to the same ash level by conventional means, because of the selective enrichment of catalytic iron minerals.     

甲烷二氧化碳重整镍基催化剂的研究

采用浸渍法制备不同组成催化剂Ni-M/γ-Al₂O₃（M=Zr、Co、Mg、Nd）,通过固定床反应装置考察不同助剂、助剂含量和反应温度对催化剂活性的影响,并对催化剂进行X射线衍射表征。结果表明,14Ni-5Mg/γ-Al₂O₃的催化活性较好,随着反应温度的升高,甲烷转化率和CO收率均升高,反应温度升至800 ℃时,甲烷转化率达97.54%。采用共沉淀法制备载体、浸渍法制备的催化剂14Ni/MgO-Al₂O₃,在反应温度800 ℃、压力1.013 kPa、n(CO₂)∶n(CH₄)=1.2和催化剂用量0.5 g条件下,CO收率高于14Ni-5Mg/γ-Al₂O₃催化剂,但甲烷转化率略低。