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铂锡双金属催化剂上丙烷脱氢反应研究 总被引:2,自引:0,他引:2
对比研究了Sn/Pt比为1;1,2,:1和5:1的原子簇担载于γ-Al2O3上制成的Pt=Sn原子簇催化剂,和用SnCl2和H2PtCl6浸渍制备的相应Sn/Pt比的催化剂对丙烷脱氢生成丙烯的催化性能。 相似文献
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On the Importance of CP-corrected Gradient Optimization in the Study of Hydrogen Bonded Systems 总被引:1,自引:0,他引:1
Geometries, harmonic vibrational frequencies and interaction energies of the water-hydrogen sulfide dimer, hydrogen fluoride dimer and glycine zwitterion-water dimer were determined by the counterpoise-corrected (CP-corrected) gradient optimization that explicitly corrects for the basis set superpusition error (BSSE) and CP-uncorrected (normal) gradient opfimization respectively at the B3LYP and MP2 levels of theory, employing the popular Pople‘s standard 6-31G(d), 6-31G(d,p) and 6-311 G(d,p) basis sets in order to assess the importance of CP-corrected gradient optimiTation in the study of hydrogen bonded systems. The normal optimization of these three H-bonded systems obtained using these popular basis sets all yielded erratic results, whereas use of CP-corrected gradient optimization led to consistent results with those from larger basis sets. So this CP receipt becomes useful and necessary to correctly describe large systems, where the use of small basis sets may be necessary. 相似文献
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研究了水溶性钯-膦配合物PdCl2(TPPTS)2催化1-己烯加氢反应,考察了两相催化体系中添加表面活性剂CTAB,膦配体TPPTS,以及溶液pH值等对反应的影响,证明了1-己烯加氢反应中有一诱导期.反应中涉及两种催化活性物种.一种是由PdCl2(TPPTS)2还原生成的低氧化态催化物种,它在一定的CTAB浓度下,可以保持相当的稳定性.另一种是被TPPTS或H2还原形成的钯黑.根据PdCl2和TPPTS反应过程的31PNMR研究,对PdCl2(TPPTS)2分子中Pd被还原和TPPTS被氧化提出了解释 相似文献
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超细Cu-ZnO-ZrO2催化剂的制备及其催化CO2加氢合成甲醇的性能 总被引:28,自引:2,他引:26
采用溶胶-凝胶法、共沉淀法和共沸蒸馏法制备了一系列不同粒度范围的超细Cu-ZnO-ZrO2催化剂,并应用BET,XRD,TEM和TPR等物理化学方法对催化剂的结构和物化性质进行了表征,同时考察了催化剂上CO2加氢合成甲醇的反应性能.结果表明,超细Cu-ZnO-ZrO2催化剂具有粒度小、颗粒分布均匀和稳定性好的特点,并发现超细Cu-ZnO-ZrO2催化剂比大颗粒的工业Cu-ZnO-Al2O3催化剂具有更高的催化活性,而且随着催化剂粒度的减小,甲醇合成活性进一步增大.研究还发现,ZrO2具有稳定反应活性中心的作用. 相似文献
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CO2加氢合成甲醇的超细Cu-ZnO-ZrO2催化剂的表征 总被引:6,自引:0,他引:6
采用原位顺磁共振(EPR)、原位X射线光电子能谱(XPS)和程序升温还原(TPR)等手段,对CO2加氢合成甲醇用的不同粒度的超细Cu-ZnO-ZrO2催化剂各组分的相互作用进行了研究。结果表明,ZrO2的加入改变了催化剂的表面结构和配位状态,增加了活性组分的分散度,提高了催化剂的稳定性。实验还发现,催化剂的粒度对各组分的相互作用有着重大的影响,催化剂的粒度较小时,Cu^2+主要以团簇的形式存在,易 相似文献
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Introduction Recently, dinuclear Ru complexes containing chelating bidentate phosphines (either chiral or non-chiral) have attracted more and more attention owing to their effective ability for catalytic hydrogenation of olefins and carbonyl groups under mild conditions. A great number of dinuclear Ru complexes with bidentate phosphines have been obtained.1-10 In 1985 Ikariya et al.1 prepared a chiral binuclear ruthenium complex [Ru2Cl4(BINAP)2]NEt3 by the reaction of (S)-BINAP with [R… 相似文献