999 resultados para Ni-MH
Resumo:
应用介电描述的复杂晶体化学键理论,给出计算Ni2+和Er3+在固体中的电子云扩大效应的新方法.
Resumo:
采用XRD、UV-DRS、XPS、TPR、H2-O2滴定和吡啶吸附-红外光谱等技术,研究了负载于具有不同酸碱性的γ-Al2O3、SiO2、MgO载体上的镍催化剂表面物理化学性质,及其对甲烷与二氧化碳重整制取合成气反应催化活性的影响.结果表明,在上述负载型镍催化剂上,影响重整反应活性和积炭量的主要原因不是催化剂表面酸碱性,而是金属镍在催化剂表面的分散度.金属与载体之间的相互作用强弱,影响金属的分散度和在反应过程中的抗烧结能力.即相互作用越强,催化剂越难还原,还原后金属在表面的分散度越大,而且在反应过程中的抗烧结能力越强,从而有利于提高催化剂在甲烷与二氧化碳重整反应中的活性和稳定性
Resumo:
采用XRD、UV-DRS、H2-O2滴定、TPR、吡啶吸附红外光谱等技术,研究了La2O3助剂对La2O3-Ni/SrAl12O19催化剂的还原性、表面酸性、金属镍的分散度和抗烧结能力,以及对催化甲烷与二氧化碳重整制取合成气反应性能的影响.结果表明,在负载型的镍催化剂中,添加La2O3助剂,能够削弱金属组分与载体之间的相互作用,降低催化剂的还原性,提高金属镍在催化剂表面的分散度和在反应过程中的抗烧结能力,降低催化剂表面酸性.关联甲烷与二氧化碳重整反应活性的结果,发现影响负载型镍催化剂的反应活性、稳定性和积炭性质的主要因素是金属镍的分散状态,而不是催化剂表面酸性.La2O3主要是通过改变镍的分散度来影响催化甲烷与二氧化碳重整反应活性的.
Resumo:
运用低能碰撞诱导解离(CID)研究了电子轰击(EI)、快原子轰击(FAB)电离条件下质子化亮氨酸与异亮氨酸解高产生亚稳离子[MH-CO2H2]+的单分子质谱碎裂,二种异构体呈现出了各自不同的解离特征,根据CID的特征碎片离子和氘代同位素标记实验,提出了其碎裂过程存在离子/中性(碎片)复合物中间体碎裂机理,并对有关的特征离子的形成进行了讨论.
Resumo:
研究了Ni/Al2O3催化剂对甲烷部分氧化制合成气的反应性能.结果表明,催化剂在其活性组份Ni为10%时反应性能最好.条件实验表明,在600~900℃范围内,甲烷转化率和CO、H2的选择性随温度升高而增加;转化率和选择性在甲烷空速≤1.5×105h-1时基本不变,空速>1.5×105h-1时,转化率和选择性有所下降.随着压力的增加(0.05~0.40MPa),转化率和选择性下降.SEM和化学分析结果证明在反应过程中,Ni组份存在烧结和流失现象.
Resumo:
研究了稀土金属氧化物(La2O3,CeO2,Pr6O11和Nd2O3)对Ni/α-Al2O3催化剂上甲烷部分氧化制合成气反应的影响.X光粉末衍射和活性考察结果表明,稀土氧化物使Ni/α-Al2O3催化剂的稳定性有显著提高.稀土氧化物与活性组份Ni之间的相互作用抑制了催化剂表面Ni晶粒的生长和迁移,由于这种作用也抑制了催化剂表面积炭的生成.在实验中还发现CeO2容易进行Ce3+Ce4+氧化还原反应而对反应具有催化活性.
Resumo:
Reaction of [Ph(4)P]2WS4 With NiCl2 in methanol solution in the presence of NaOCH3 leads to the formation of [Ph(4)P](2) [S2W(mu-S)(2)Ni(S-2)] (I) A Similar reaction between (NH4)(2)WS4 and NiCl2 under O-2 atmosphere in the presence of Ph(4)PCl or (n)Bu(4)NCl affords [Ph(4)P](2)([(S-2)W(O)(mu-S)(2)]Ni-2] (IIa) and [(n)Bu(4)N](2)([(S-2)W(O)(mu-S)(2)]Ni-2} (IIb) Under argon the same reaction gives [Ph(4)P](2)[Ni(WS4)(2)] (IIIa) and [(n)Bu(4)N](2)[Ni(WS4)(2)] (IIIb). [Ph(4)P](2)[Ni(WOS3)(2)] (IV) and [Ph(4)P](2)[Ni(WO2S2)(2)] (V) can be prepared from the reaction of [Ph(4)P]2WOS3 and [Ph(4)P]2WO2S2 with NiCl2. Treatment of (NH4)(2)WS4 with CuCl in the presence of PPh(3) in boiling pyridine produces W(mu-S)(4)Cu-2(PPh(3))(3) (VI), which can further react with excess PPh(3) to give W(mu-S)(4)Cu-2(PPh(3))(4) . py (VII). Complex I crystallizes in the space group P2(1)/n with the cell parameters: a = 20.049(4), b = 17.010(4), c = 14.311(7) Angstrom; beta = 110.24(3)degrees and Z = 4; R = 0.058 for 4267 independent reflections. The structural study confirms that complex I contains two terminal sulfide ligands, two bridging sulfide ligands, a side-on disulfide ligand, and a planar central W(mu-S)(2)Ni four membered ring. Complex VII crystallizes in the space group C2/c with the cell parameters: a = 26.436(8), b = 20.542(6), c = 19.095(8) Angstrom; beta = 125.00(3)degrees and Z = 4; R = 0.080 for 3802 independent reflections. The structural study reveals a perfect linear arrangement of the three metal atoms Cu-W-Cu.
Resumo:
With XRD, R-T, and ac chi measurements a comparative study on the doping effects of 3d elements in Bi(1.5)Pb(0.2)Sr(2)Ca(2)Cu(2.8)M(0.2)O(y) (M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, or Zn) has been carried out. The effects of the former five members are significantly different, both on phase formed and on T-c, from the latter four. It seems that the effect on phase stabilization correlates with the valency of the doped cation. In connection with the instability of the 2223 phase, the correlation has been discussed.
Resumo:
The mixed oxides LaNiO3, La0.1Sr0.9NiO3, La2NiO4 and LaSrNiO4 with perovskite (ABO(3)) and related(A(2)BO(4)) structures were prepared and the adsorption property for NO and the catalytic activity for NO decomposition over these oxidse were also tested. The catalysts were characterized by means of BET surface measurement, chemical analysis, NO-TPD etc.. It was shown that the adsorption amount of NO is correlated with the concentration of oxygen vacancy formed and the adsorption type and strength of NO are related to the valence of metallic ion. Generally there are three kinds of adsorption species, NO-, NO+ and NO on the mixed oxides, among them the negative adsorpion species (NO-) are active for NO decomposition. The weaker the adsorption of oxygen on the catalyst is, the faster the mobility of oxygen is and the easier the redox process takes place in reproducing the active sites in which the oxygen species (O-, O2-) would participate.
Resumo:
合成了具有钙钛石和类钙钛石结构的复合氧化物LaNiO_3、La_(0.1)Sr_(0.9)NiO_3、La_2NiO_4和LaSrNiO_4.考察了它们对NO的吸附和NO直接分解反应的催化性能;结合比表面测定、化学分析、XRD和NO-TPD对催化剂的表征结果,探讨了该系列复合氧化物对NO的吸附规律。
Resumo:
(TPP)Ni(Ⅱ)氧化反应的电化学和光谱电化学研究严川伟,王振新,林祥钦(中国科学院长春应用化学研究所电分析化学开放实验室,国家电化学和光谱研究分析中心长春130022)关键词镍卟啉,阴离子配位,电化学,光谱电化学镍卟啉是一类重要的仿生模型化合物,...
Resumo:
The compound [FeCp(Tol)](2)[Ni(mnt)(2)] has been prepared from [FeCp(Tol)]AlCl4 and Na-2[Ni(mnt)(2)]. This new organometallic radical ionic salt has been characterized by elemental analysis, IR, H-1 NMR and mass spectroscopy. The X-ray structure of the compound shows there are segregated cation and anion stacks in the perpendicular directions, The molecular anions form a zig-zag stacking along the b axis, and between every two neighbouring anion planes a methyl group of the cation is inserted. This gives rise to a long spacing of 6.87 Angstrom, between the anion planes. The cations stack along the c axis, with the closest spacing of 3.457 Angstrom between the cyclopentadienyl plane and the neighbouring toluene plane, which is shorter than the sum of Van der Wall's radii. Conductivity measurements showed the compound as a semiconductor with a room temperature conductivity of 1.6 X 10(-4) Scm(-1).
Resumo:
The binuclear complex [Ni(oxae)Ni(phen)2](ClO4)(2) . H2O (oxae=N,N'bis(2-aminoethyl) oxamido dianion, phen = 1, 10-phenanthroline) was prepared from the planar monomeric complex Ni(oxae) and characterized through analytical and spectroscopic measurements. The structure of [Ni(oxae)Ni(phen)(2)] (ClO4)2 . 3H(2)O was investigated by single-crystal X-ray analysis. The complex has an extended oxamido-bridged structure and consists of two nickel(II) ions, one of them in a square planar environment and another in a distorted octahedral environment. The Ni-Ni distance is 5.267 Angstrom.
Resumo:
电解液添加成份对贮氢电极性能影响的初步研究蔡称心,黄翠虹(南京大学化学系,南京,210008)王宝忱(中国科学院长春应用化学研究所,长春130022)关键词:贮氢电极,MH/Ni电池,添加剂自从Justi和Ewe ̄[1,2]发现贮氢合金能够用电化学方...
Resumo:
4-(2-氨基噻唑)-间苯二酚为柱前衍化剂液相色谱/电化学检测Fe、Co、Ni格日勒,李惠梅,李南强,汪尔康(中国科学院长春应用化学研究所电分析化学开放实验室,北京大学化学系,长春,130022)关键词液相色谱,Fe,Co,Ni,4-(2-氨基噻唑)...