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利用环三膦腈衍生六(4-甲酰基苯氧基)环三磷腈(H6L1)与La/Nd(NO_3)_3·6H_2O在H_2O/DMF溶剂体系,于相似合成条件下制备了两种异构配位聚合物,即{[La_2(C_(42)H_(24)O_(18)P_3N_3)(H_2O)4]·(H_2O)3}n(1),{[Nd2(C42H24O18P3N3)(H_2O)_3(C_2H_5OH)]·(H_2O)_3}n(2)。化合物1和2具有2D层晶体结构,其中延伸的六羧酸配体连接稀土金属离子形成最终的拓扑网络结构。在这两种化合物中,配体L1完全去质子化,其六个延伸的羧基臂连接四个金属节点以形成高维度框架。此外,还进行了两种配合物进行了IR,TGA和XRD表征。 相似文献
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以ANPyO、Zn(CH_3COO)_2·2H_2O和DMSO作原料,通过溶液法合成了含能配合物Zn_4(C_4N_6O_5H_2)_4(DMSO)_4,采用傅立叶变换红外光谱、元素分析、X-射线单晶衍射、差示扫描量热法(DSC)和热重分析法(TG)对其结构进行了表征,用Kissinger和Ozawa法计算了配合物放热过程的表观活化能。研究了配合物对黑索今(RDX)、奥克托今(HMX)和高氯酸铵(AP)热分解的催化效果,测试了其撞击感度和摩擦感度。结果表明,配合物属单斜晶系,空间群为P2_1/C。配合物热分解过程有一个吸热峰和一个放热峰,剩余残渣质量分数为14.38%;表观活化能为225.56 kJ/mol;配合物对RDX和HMX热分解催化效果不明显,但对AP具有非常显著的催化效果;配合物对撞击和摩擦钝感。 相似文献
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《合成技术及应用》2021,(3)
为了提高镍金属催化剂的催化性能,合成了咪唑啉2-亚胺配体双配位的N-酰化咪唑啉镍配合物Ni1和Ni2。并通过核磁及单晶X-射线衍射表征了镍配合物的结构。添加4当量的B(C_6F_5)_3为助催化剂时,配合物Ni2催化乙烯齐聚活性高达2.9×10~6 g/(mol·h)。该体系配合物同样有效催化降冰片烯均聚,聚合活性随B(C_6F_5)_3添加量的增加而增加,当B∶Ni比为10时Ni2的催化活性高达2.59×10~6 g/(mol·h)。该体系催化剂对乙烯齐聚和降冰片烯均聚均表现出良好的聚合性能,这为高效烯烃聚合领域,新型配体结构设计提供了良好的参考价值。 相似文献
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《广东化工》2018,(20)
水热条件下,合成了一个新的镍(Ⅱ)配合物[Ni(L)_2(BAA)]·2H_2O(H_2BAA=苯乙酸,L=2-(2-氯-6-氟苯基)-1H-咪唑[4,5-f][1,10]邻菲罗啉),并对该配合物进行了元素分析和单晶X–射线衍射表征。该化合物属于三斜晶系,空间群P-1,晶胞参数a=10.442(2),b=13.470(3),c=15.241(3)?,α=83.72(3),β=84.46(3),γ=78.34(3)o,V=2080.8(7)?~3,Z=2,C_(46)H_(31)NiN_8O_4F_2Cl_2,M_r=927.38,D_c=1.480 g/cm~3,F(000)=950,μ(MoKa)=0.660 mm~(-1),R=0.1038和w=0.2523。配合物1中,镍(Ⅱ)离子与2个来自苯乙酸上的O原子,来自2个L配体分子上的4个N原子配位,形成6配位的八面体配位几何构型。 相似文献
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《化工科技》2016,(5)
比较了Mn(CH_3SO_3)_2·2H_2O、Cu(CH_3SO_3)_2·4H_2O、Zn(CH_3SO_3)_2·4H_2O、Co(CH_3SO_3)_2·4H_2O四种过渡金属甲基磺酸盐催化乙酸与正丁醇酯化反应的活性。其中Cu(CH_3SO_3)_2·4H_2O、Zn(CH_3SO_3)_2·4H_2O和Co(CH3SO3)2·4H_2O催化活性最高,而Mn(CH_3SO_3)_2·2H_2O活性较低。以Cu(CH_3SO_3)_2·4H_2O为催化剂,环己烷为带水剂,确定了适宜的反应条件为:n(乙酸)=0.2mol,n(醇)∶n(酸)=1.2,x(催化剂)=0.5%,V(环己烷)=15mL,反应时间86min,酯化率100%。同时,催化剂经过简单的相分离之后可以多次使用。 相似文献
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The synthesis and spectral properties of novel phthalocyanines with pendant bulky units 总被引:1,自引:0,他引:1
Novel phthalocyanines with biphenyl substituents and ester groups that are readily soluble in organic solvents were synthesized from a phthalonitrile derivative obtained by displacement of the –CH proton in 1-chloro-3,4-dicyano-6-(1,1-dicarbethoxymethyl)benzene with 4-(chloromethyl)biphenyl, followed by cyclotetramerization in the presence of metal salts {CuCl2, Pb(CH3COO)2·3H2O, CoCl2 and Zn(CH3COO)2}. Transesterification of malonyl esters occurred during the cyclotetramerization of dinitrile with CuCl2, Pb(CH3COO)2·3H2O in 1-pentanol in the presence of DBU. The structures of the newly synthesized molecules were verified using elemental analysis, 1H NMR, FT-IR, MicroTOF mass and UV–vis spectral data. 相似文献
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Effect of additives, In2O3, SnO2, CoO, CuO and Ag, on the catalytic performance of Ga2O3–Al2O3 prepared by sol–gel method for the selective reduction of NO with propene in the presence of oxygen was studied. As for the reaction in the absence of H2O, CoO, CuO and Ag showed good additive effect. When H2O was added to the reaction gas, the activity of CoO-, CuO- and Ag-doped Ga2O3–Al2O3 was depressed considerably, while an intensifying effect of H2O was observed for In2O3- and SnO2-doped Ga2O3–Al2O3. Of several metal oxide additives, In2O3-doped Ga2O3–Al2O3 showed the highest activity for NO reduction by propene in the presence of H2O. Kinetic studies on NO reduction over In2O3–Ga2O3–Al2O3 revealed that the rate-determining step in the absence of H2O is the reaction of NO2 formed on Ga2O3–Al2O3 with C3H6-derived species, whereas that in the presence of H2O is the formation of C3H6-derived species. We presumed the reason for the promotional effect of H2O as follows: the rate for the formation of C3H6-derived species in the presence of H2O is sufficiently fast compared with that for the reaction of NO2 with C3H6-derived species in the absence of H2O. Although the retarding effect of SO2 on the activity was observed for all of the catalysts, SnO2–Ga2O3–Al2O3 showed still relatively high activity in the lower temperature region. 相似文献
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Runduo Zhang Houshang Alamdari Serge Kaliaguine 《Applied catalysis. B, Environmental》2007,72(3-4):331-341
A series of La(Co, Mn, Fe)1−x(Cu, Pd)xO3 perovskites having high specific surface areas and nanosized crystal domains was prepared by reactive grinding. The solids were characterized by N2 adsorption, X-ray diffraction (XRD), scanning electron microscopy (SEM), temperature programmed desorption (TPD) of O2, NO + O2, C3H6, in the absence or presence of 5% H2O, Fourier transform infrared (FTIR) spectroscopy, as well as activity tests towards NO reduction by propene under the conditions of 3000 ppm NO, 3000 ppm C3H6, 1% O2, 0 or 10% H2O, and 50,000 h−1 space velocity. The objective was to investigate the influence of H2O addition on catalytic behavior. A good performance (100% NO conversion, 77% N2 yield, and 90% C3H6 conversion) was achieved at 600 °C over LaFe0.8Cu0.2O3 under a dry feed stream. With the exposure of LaFe0.8Cu0.2O3 to a humid atmosphere containing 10% water vapor, the catalytic activity was slightly decreased yielding 91% NO conversion, 51% N2 yield, and 86% C3H6 conversion. A competitive adsorption between H2O vapor with O2 and NO molecules at anion vacancies over LaFe0.8Cu0.2O3 was found by means of TPD studies here. A deactivation mechanism was therefore proposed involving the occupation of available active sites by water vapor, resulting in an inhibition of catalytic activity in C3H6 + NO + O2 reaction. This H2O deactivation was also verified to be strictly reversible by removing steam from the feed. 相似文献
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Water-soluble niobium peroxo complexes as precursors for the preparation of Nb-based oxide catalysts 总被引:1,自引:0,他引:1
In the frame of research aimed at developing new synthetic procedures of multimetallic Nb-based catalysts, peroxo complexes of niobium(V) of general formula AI3[Nb(O2)4] and AI3[Nb(O2)x(HyL)]·nH2O (AI: NH4+, CN3H6+ (gu); L: oxalate, tartrate, citrate) have been prepared and characterized on the basis of elemental and thermal analysis, FTIR and 13C-NMR spectra. The crystal structure of (gu)3[Nb(O2)4] and (gu)3[Nb(O2)2(C2O4)2]·2H2O have been determined. The application of the obtained Nb complexes as precursors for the preparation of silica-supported Nb–Mo–O catalysts has been demonstrated. Combining Nb peroxo-carboxylato compounds with analogous Mo(VI) compounds in a silica-impregnation method carried out in aqueous medium leads to the formation of the supported Nb2Mo3O14 phase. 相似文献
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The effect of oxygen concentration on the pulse and steady-state selective catalytic reduction (SCR) of NO with C3H6 over CuO/γ-Al2O3 has been studied by infrared spectroscopy (IR) coupled with mass spectroscopy studies. IR studies revealed that the pulse SCR occurred via (i) the oxidation of Cu0/Cu+ to Cu2+ by NO and O2, (ii) the co-adsorption of NO/NO2/O2 to produce Cu2+(NO3−)2, and (iii) the reaction of Cu2+(NO3−)2 with C3H6 to produce N2, CO2, and H2O. Increasing the O2/NO ratio from 25.0 to 83.4 promotes the formation of NO2 from gas phase oxidation of NO, resulting in a reactant mixture of NO/NO2/O2. This reactant mixture allows the formation of Cu2+(NO3−)2 and its reaction with the C3H6 to occur at a higher rate with a higher selectivity toward N2 than the low O2/NO flow. Both the high and low O2/NO steady-state SCR reactions follow the same pathway, proceeding via adsorbed C3H7---NO2, C3H7---ONO, CH3COO−, Cu0---CN, and Cu+---NCO intermediates toward N2, CO2, and H2O products. High O2 concentration in the high O2/NO SCR accelerates both the formation and destruction of adsorbates, resulting in their intensities similar to the low O2/NO SCR at 523–698 K. High O2 concentration in the reactant mixture resulted in a higher rate of destruction of the intermediates than low O2 concentration at temperatures above 723 K. 相似文献
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Yuichi Kamiya Satoshi Ueki Norihito Hiyoshi Naoki Yamamoto Toshio Okuhara 《Catalysis Today》2003,78(1-4):281-290
A new method through intercalation and exfoliation of VOPO4·2H2O crystallites in primary alcohol (1-propanol or 1-butanol), followed by reduction with the alcohol, have been investigated for the preparation of catalyst precursor. Lamellar compounds, consisting of V4+, P5+ and alkyl group with thin film-like morphology, were formed and was characterized by means of XRD, IR, TG/DTA, and elemental analysis. The chemical formula of the precursor obtained by exfoliation–reduction in 1-butanol was shown to be VO{(n-C4H9)0.16H0.84}PO4·0.8H2O. On the other hand, a direct reduction of VOPO4·2H2O in the alcohol gave a mixed phase shown by (VOHPO4·0.5H2O)0.3(VO{(n-C4H9)0.3H0.7}PO4·3H2O)0.7 comprising plate-like microcrystallites. These precursors transformed to (VO)2P2O7 phase during an activation process at 703 K in the presence of a mixture of n-butane 1.5% and O2 17% in He balance. The obtained (VO)2P2O7 through the exfoliation–reduction was well crystallized and consisted of thin flaky crystallites. It was found that (VO)2P2O7 thus prepared through the exfoliation–reduction was highly active and selective for oxidation of n-butane. 相似文献
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二甲醚是一种理想的氢载体,可用于解决氢的储存和运输。以Pt/TiO_2为部分氧化催化剂,结合Ni/Al_2O_3重整催化剂,考察钛前驱体和焙烧温度对二甲醚部分氧化重整制氢反应的影响。结果表明,以Ti(C4H9O)4为原料制备的TiO_2为金红石相,Ti(SO4)2或Ti O(OH)2为原料制备的TiO_2为锐钛矿相;以Ti(C4H9O)4为原料制备的Pt/TiO_2-E催化剂催化性能略好,转化率接近100%,H2收率约90%,表明金红石相TiO_2负载的Pt催化剂略佳;以Ti(SO4)2为原料制备的Pt/TiO_2-S催化剂500℃焙烧可获得金红石相TiO_2。与Pt/Al_2O_3催化剂相比,Pt/TiO_2催化剂具有更好的催化性能,H2收率超过90%,而Pt/Al_2O_3催化剂H2收率约80%。 相似文献
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The effect of the addition of a second fuel such as CO, C3H8 or H2 on the catalytic combustion of methane was investigated over ceramic monoliths coated with LaMnO3/La-γAl2O3 catalyst. Results of autothermal ignition of different binary fuel mixtures characterised by the same overall heating value show that the presence of a more reactive compound reduces the minimum pre-heating temperature necessary to burn methane. The effect is more pronounced for the addition of CO and very similar for C3H8 and H2. Order of reactivity of the different fuels established in isothermal activity measurements was: CO>H2≥C3H8>CH4. Under autothermal conditions, nearly complete methane conversion is obtained with catalyst temperatures around 800 °C mainly through heterogeneous reactions, with about 60–70 ppm of unburned CH4 when pure methane or CO/CH4 mixtures are used. For H2/CH4 and C3H8/CH4 mixtures, emissions of unburned methane are lower, probably due to the proceeding of CH4 homogeneous oxidation promoted by H and OH radicals generated by propane and hydrogen pyrolysis at such relatively high temperatures.
Finally, a steady state multiplicity is found by decreasing the pre-heating temperature from the ignited state. This occurrence can be successfully employed to pilot the catalytic ignition of methane at temperatures close to compressor discharge or easily achieved in regenerative burners. 相似文献
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由金属醇盐水解制备溶胶的方法已广泛应用于溶胶-凝胶法制备纳米孔无机膜,但对金属醇盐水解机理的认识十分有限。通过控制异丙醇钛[Ti(i-OC3H7)4]在异丙醇(i-C3H7OH)中水解制备TiO2溶胶,利用小角X射线散射(SAXS)方法研究了由不同H2O/Ti(i-OC3H7)4的反应混合物[Ti(i-OC3H7)4:H2O:i-C3H7OH=1:m:30(摩尔比)]形成TiO2溶胶的过程,探讨了控制Ti(i-OC3H7)4水解的过程中胶粒形成与长大的规律。研究结果表明,所合成的TiO2溶胶的胶粒粒径小于10 nm,胶粒的形成和长大与H2O/Ti(i-OC3H7)4摩尔比密切相关。H2O/Ti(i-OC3H7)4(摩尔比) ≥ 2.0时,随着H2O/Ti(i-OC3H7)4增加,溶胶的稳定性下降。 相似文献