氮化硅是一种良好的载体,具有较高的水热稳定性和机械稳定性,其表面的氨基基团能够较好地锚定金属,显著提高金属分散度。但是,商品氮化硅比表面积较低,对金属分散作用仍然有限。因此,以自制的高比表面积氮化硅(Si_(3)N_(4))为载体,通过...氮化硅是一种良好的载体,具有较高的水热稳定性和机械稳定性,其表面的氨基基团能够较好地锚定金属,显著提高金属分散度。但是,商品氮化硅比表面积较低,对金属分散作用仍然有限。因此,以自制的高比表面积氮化硅(Si_(3)N_(4))为载体,通过浸渍法制备了不同Ru负载量(质量分数分别为0.5%、1.0%和2.0%)的催化剂(分别为0.5%Ru/Si_(3)N_(4)、1.0%Ru/Si_(3)N_(4)和2.0%Ru/Si_(3)N_(4)),并以商品氮化硅(Si_(3)N_(4)-C)为载体制备了2.0%Ru/Si_(3)N_(4)-C催化剂作为对照组。表征了催化剂的理化性质,测试了其在300℃、0.1 MPa下的CO_(2)加氢反应活性。结果显示,与Si_(3)N_(4)-C相比,Si_(3)N_(4)的比表面积较高(502 m^(2)/g),Si_(3)N_(4)作为载体显著提高了金属分散度,降低了金属粒径,催化剂暴露出更多的活性位点。0.5%Ru/Si_(3)N_(4)的金属粒径较小,展现出强的H_(2)吸附能力,H难以解吸,抑制了中间物种CO加氢生成CH_(4)。随着Ru负载量增加,金属粒径增大,催化剂的CH_(4)选择性更好。Ru/Si_(3)N_(4)系列催化剂中,2.0%Ru/Si_(3)N_(4)的CH_(4)选择性较高(98.8%)。空速为10000 m L/(g·h)时,0.5%Ru/Si_(3)N_(4)的CO选择性为88.2%。与2.0%Ru/Si_(3)N_(4)相比,2.0%Ru/Si_(3)N_(4)-C的金属粒径更大,活性位点较少,活性更低。2.0%Ru/Si_(3)N_(4)和2.0%Ru/Si_(3)N_(4)-C的CO_(2)转化率分别为53.1%和9.2%。Si_(3)N_(4)有效提高了金属分散度,提高了催化剂的CO_(2)加氢反应活性;通过调控Ru负载量控制催化剂金属粒径,可实现对产物CO或CH_(4)选择性的调控。展开更多
A coupled chemiluminescence method for the determination of some carhoxylic acids was devel-oped, based on their enhancement the chemiluminescence light emission of the reaction of tirs(2, 2'-bipyri-dine) rutheni...A coupled chemiluminescence method for the determination of some carhoxylic acids was devel-oped, based on their enhancement the chemiluminescence light emission of the reaction of tirs(2, 2'-bipyri-dine) ruthenium(Ⅱ) and Ce(Ⅳ) in sulfuric acid medium. The conditions for their determination were opti-mized. The following detection limits were obtained: oxalic acid, 2. 67×10-8 mol/L; propandioic acld, 1.20×10-6 mol/L; pyruvic acid, 1. 35 ×10-8 mol/L; citric acid, 5.10×10-8. mol/L; barbituric acid, 2.48×10-7,mol/L. The proposed method was successfully applied to determination or oxalic acid. The coupled chemilu-minescent reaction mechanism and rate equation are proposed.展开更多
The fullerene complex, η 2 C 60 [Ru(NO)(PPh 3)] 2, has been prepared by the reaction of C 60 with Ru(NO) 2(PPh 3) 2 under a nitrogen atmosphere and refluxing. The new complex was characterized by means of elemental a...The fullerene complex, η 2 C 60 [Ru(NO)(PPh 3)] 2, has been prepared by the reaction of C 60 with Ru(NO) 2(PPh 3) 2 under a nitrogen atmosphere and refluxing. The new complex was characterized by means of elemental analysis, IR, XPS, electronic spectra and 31 P NMR. The results show that the complex of η 2 form can be formed by C 60 bonding to Ru(NO) 2(PPh 3) 2 in the σ π way and there is hyperconjugation effect in the molecule. So electrons will flow easier and photoelectric effect for this new compound is expected. In addition, the structure of the complex has been supposed. The ruthenium is 4 coordinate in the complex, bonding to two carbon atoms, to one PPh 3 and to one NO.展开更多
A novel octamolybdate complex, [Fe(2,2?bipy)3]2[Mo8O26]6H2O has been synthesized via the hydrothermal technique, and it crystallizes in monoclinic, space group P21/c with two molecules in a unit cell: a = 1.21512(5), ...A novel octamolybdate complex, [Fe(2,2?bipy)3]2[Mo8O26]6H2O has been synthesized via the hydrothermal technique, and it crystallizes in monoclinic, space group P21/c with two molecules in a unit cell: a = 1.21512(5), b = 1.36840(5), c = 2.18823(9) nm, b = 90.515(1), Mr = 2340.42, Z = 2, V = 3.6384(2) nm3, Dc = 2.136 g/cm3, F(000) = 2296, l(MoKa) = 0.071073 nm, = 1.813 mm-1, R = 0.0719 and wR = 0.1093 for 4058 observed reflections with I≥2s(I). The structure is characterized by the co-existence of octahedral [Fe(2,2?bipy)3]2+ cations and b-octamolybdate [Mo8O26]4- anions. The magnetic susceptibility data show a Curie-Weiss paramagnetic behavior (q = -5.201 K) in accordance with the spin-only ground state of FeⅡ ions. IR, UV-Vis, and EPR spectra are also briefly noted in this paper.展开更多
Tris(bipyridine)ruthenium(Ⅱ)(Ru(bpy) 2+ 3) was incorporated into mesoporous silicate MCM 48. X ray diffraction and emission spectroscopy were used to investigate the products, Ru(bpy) 2+ 3/MCM 48. The emission spectr...Tris(bipyridine)ruthenium(Ⅱ)(Ru(bpy) 2+ 3) was incorporated into mesoporous silicate MCM 48. X ray diffraction and emission spectroscopy were used to investigate the products, Ru(bpy) 2+ 3/MCM 48. The emission spectra show that the wavelength of maximum intensity( λ max ) for Ru(bpy) 2+ 3 increases with the increase of Ru(bpy) 2+ 3 loading level in MCM 48. The photoluminescent property of Ru(bpy) 2+ 3/MCM 48 was investigated. It was observed that the wavelength maximum intensity( λ max ) for Ru(bpy) 2+ 3/MCM 48 was red shifted when acetone vapor was introduced. [WT5HZ]展开更多
The bimetallic catalyst Ru-Pt/ γ -Al 2O 3 was prepared by impregnating H 2PtCl 6 and RuCl 3 aqueous solution in the presence of PVP(40 000). Its catalytic performance in selective hydrogenation of \{ p -chloronitrobe...The bimetallic catalyst Ru-Pt/ γ -Al 2O 3 was prepared by impregnating H 2PtCl 6 and RuCl 3 aqueous solution in the presence of PVP(40 000). Its catalytic performance in selective hydrogenation of \{ p -chloronitrobenzene\}( p -CNB) was studied. The results indicate that the activity of Ru-Pt/ γ -Al 2O 3[\{ n (ruthenium)\}∶ n (platinum)=4∶1] is much higher than that of Ru/ γ -Al 2O 3,while the amount of dehalogenation product(aniline) and other by-products are much fewer than that by using Pt/ γ -Al 2O 3 as the catalyst. There is synergistic effect of ruthenium and platinum in bimetallic catalyst for selective hydrogenation of p -CNB. Under the reaction conditions t =50 ℃, p H 2 = 1.0 MPa, reaction time 60 min,\{ n (substrate)∶\} n (total amount of metal content)=1000∶1,the conversion of p -CNB and the selectivity to p -chloroaniline( p -CNA) by using Ru-Pt/ γ -Al 2O 3 as the catalyst are 48.2% and 85.9%,respectively. The effect of other metal cations(introduced to the reaction system with the corresponding metal chloride solution) on the reaction was investigated. It was found that catalytic performance of Ru-Pt/ γ -Al 2O 3 could be greatly improved by modfication of some metal cations. When Co 2+ and Ni 2+ were used as modifiers for the catalyst Ru-Pt/ γ -Al 2O 3 under above mentioned reaction conditions,the conversions of p -CNB increase to 74.5% and 87.8%,as well as the selectivities of p -CAN increase to 98.9% and 99.4%,respectively. Fe 3+ and Sn 4+ were the best modifiers for Ru-Pt/ γ -Al 2O 3 under the same reaction conditions. The conversions of p -CNB and the selectivities of p -CAN can reach 100% and >99.0%,respectively. However,the catalysts can be poisoned by Zn 2+ and Sn 2+ .展开更多
文摘氮化硅是一种良好的载体,具有较高的水热稳定性和机械稳定性,其表面的氨基基团能够较好地锚定金属,显著提高金属分散度。但是,商品氮化硅比表面积较低,对金属分散作用仍然有限。因此,以自制的高比表面积氮化硅(Si_(3)N_(4))为载体,通过浸渍法制备了不同Ru负载量(质量分数分别为0.5%、1.0%和2.0%)的催化剂(分别为0.5%Ru/Si_(3)N_(4)、1.0%Ru/Si_(3)N_(4)和2.0%Ru/Si_(3)N_(4)),并以商品氮化硅(Si_(3)N_(4)-C)为载体制备了2.0%Ru/Si_(3)N_(4)-C催化剂作为对照组。表征了催化剂的理化性质,测试了其在300℃、0.1 MPa下的CO_(2)加氢反应活性。结果显示,与Si_(3)N_(4)-C相比,Si_(3)N_(4)的比表面积较高(502 m^(2)/g),Si_(3)N_(4)作为载体显著提高了金属分散度,降低了金属粒径,催化剂暴露出更多的活性位点。0.5%Ru/Si_(3)N_(4)的金属粒径较小,展现出强的H_(2)吸附能力,H难以解吸,抑制了中间物种CO加氢生成CH_(4)。随着Ru负载量增加,金属粒径增大,催化剂的CH_(4)选择性更好。Ru/Si_(3)N_(4)系列催化剂中,2.0%Ru/Si_(3)N_(4)的CH_(4)选择性较高(98.8%)。空速为10000 m L/(g·h)时,0.5%Ru/Si_(3)N_(4)的CO选择性为88.2%。与2.0%Ru/Si_(3)N_(4)相比,2.0%Ru/Si_(3)N_(4)-C的金属粒径更大,活性位点较少,活性更低。2.0%Ru/Si_(3)N_(4)和2.0%Ru/Si_(3)N_(4)-C的CO_(2)转化率分别为53.1%和9.2%。Si_(3)N_(4)有效提高了金属分散度,提高了催化剂的CO_(2)加氢反应活性;通过调控Ru负载量控制催化剂金属粒径,可实现对产物CO或CH_(4)选择性的调控。
文摘A coupled chemiluminescence method for the determination of some carhoxylic acids was devel-oped, based on their enhancement the chemiluminescence light emission of the reaction of tirs(2, 2'-bipyri-dine) ruthenium(Ⅱ) and Ce(Ⅳ) in sulfuric acid medium. The conditions for their determination were opti-mized. The following detection limits were obtained: oxalic acid, 2. 67×10-8 mol/L; propandioic acld, 1.20×10-6 mol/L; pyruvic acid, 1. 35 ×10-8 mol/L; citric acid, 5.10×10-8. mol/L; barbituric acid, 2.48×10-7,mol/L. The proposed method was successfully applied to determination or oxalic acid. The coupled chemilu-minescent reaction mechanism and rate equation are proposed.
文摘The fullerene complex, η 2 C 60 [Ru(NO)(PPh 3)] 2, has been prepared by the reaction of C 60 with Ru(NO) 2(PPh 3) 2 under a nitrogen atmosphere and refluxing. The new complex was characterized by means of elemental analysis, IR, XPS, electronic spectra and 31 P NMR. The results show that the complex of η 2 form can be formed by C 60 bonding to Ru(NO) 2(PPh 3) 2 in the σ π way and there is hyperconjugation effect in the molecule. So electrons will flow easier and photoelectric effect for this new compound is expected. In addition, the structure of the complex has been supposed. The ruthenium is 4 coordinate in the complex, bonding to two carbon atoms, to one PPh 3 and to one NO.
基金This work was supported by the Introduction of Overseas Elitists Program (No.IB990168) the Chinese Academy of Sciences
文摘A novel octamolybdate complex, [Fe(2,2?bipy)3]2[Mo8O26]6H2O has been synthesized via the hydrothermal technique, and it crystallizes in monoclinic, space group P21/c with two molecules in a unit cell: a = 1.21512(5), b = 1.36840(5), c = 2.18823(9) nm, b = 90.515(1), Mr = 2340.42, Z = 2, V = 3.6384(2) nm3, Dc = 2.136 g/cm3, F(000) = 2296, l(MoKa) = 0.071073 nm, = 1.813 mm-1, R = 0.0719 and wR = 0.1093 for 4058 observed reflections with I≥2s(I). The structure is characterized by the co-existence of octahedral [Fe(2,2?bipy)3]2+ cations and b-octamolybdate [Mo8O26]4- anions. The magnetic susceptibility data show a Curie-Weiss paramagnetic behavior (q = -5.201 K) in accordance with the spin-only ground state of FeⅡ ions. IR, UV-Vis, and EPR spectra are also briefly noted in this paper.
文摘Tris(bipyridine)ruthenium(Ⅱ)(Ru(bpy) 2+ 3) was incorporated into mesoporous silicate MCM 48. X ray diffraction and emission spectroscopy were used to investigate the products, Ru(bpy) 2+ 3/MCM 48. The emission spectra show that the wavelength of maximum intensity( λ max ) for Ru(bpy) 2+ 3 increases with the increase of Ru(bpy) 2+ 3 loading level in MCM 48. The photoluminescent property of Ru(bpy) 2+ 3/MCM 48 was investigated. It was observed that the wavelength maximum intensity( λ max ) for Ru(bpy) 2+ 3/MCM 48 was red shifted when acetone vapor was introduced. [WT5HZ]
文摘The bimetallic catalyst Ru-Pt/ γ -Al 2O 3 was prepared by impregnating H 2PtCl 6 and RuCl 3 aqueous solution in the presence of PVP(40 000). Its catalytic performance in selective hydrogenation of \{ p -chloronitrobenzene\}( p -CNB) was studied. The results indicate that the activity of Ru-Pt/ γ -Al 2O 3[\{ n (ruthenium)\}∶ n (platinum)=4∶1] is much higher than that of Ru/ γ -Al 2O 3,while the amount of dehalogenation product(aniline) and other by-products are much fewer than that by using Pt/ γ -Al 2O 3 as the catalyst. There is synergistic effect of ruthenium and platinum in bimetallic catalyst for selective hydrogenation of p -CNB. Under the reaction conditions t =50 ℃, p H 2 = 1.0 MPa, reaction time 60 min,\{ n (substrate)∶\} n (total amount of metal content)=1000∶1,the conversion of p -CNB and the selectivity to p -chloroaniline( p -CNA) by using Ru-Pt/ γ -Al 2O 3 as the catalyst are 48.2% and 85.9%,respectively. The effect of other metal cations(introduced to the reaction system with the corresponding metal chloride solution) on the reaction was investigated. It was found that catalytic performance of Ru-Pt/ γ -Al 2O 3 could be greatly improved by modfication of some metal cations. When Co 2+ and Ni 2+ were used as modifiers for the catalyst Ru-Pt/ γ -Al 2O 3 under above mentioned reaction conditions,the conversions of p -CNB increase to 74.5% and 87.8%,as well as the selectivities of p -CAN increase to 98.9% and 99.4%,respectively. Fe 3+ and Sn 4+ were the best modifiers for Ru-Pt/ γ -Al 2O 3 under the same reaction conditions. The conversions of p -CNB and the selectivities of p -CAN can reach 100% and >99.0%,respectively. However,the catalysts can be poisoned by Zn 2+ and Sn 2+ .
