PdAg/MIL-101(Fe)催化NaBH4水解制氢

将PdAg纳米颗粒负载到MIL-101(Fe)上作为硼氢化钠水解制氢的催化剂。采用XRD、TEM、HRTEM、XPS、SEM和EDS等方法对催化剂PdAg/MIL-101(Fe)的结构进行了表征。PdAg/MIL-101(Fe)在硼氢化钠水解制氢中表现出较高的催化活性,在温和的条件下水解制氢最大速率为2.60 L·min^–1·g_cat.^–1。详细研究了反应温度、催化剂用量、氢氧化钠和硼氢化钠浓度对该催化反应的影响规律。结果发现,制氢速率很大程度上依赖于反应温度,随着反应温度的升高,制氢速率明显增加,制氢的表观活化能为54.89 kJ·mol^–1。该催化剂重用性能好,5次循环后仍能保持活性。     

Growth mechanism of palladium clusters on rutile TiO2 （110） surface

Oxide-supported transition metal systems have been the subject of enormous interest due to the improvement of catalytic properties relative to the separate metal.Thus in this paper,we embark on a systematic study for Pd n (n=1-5) clusters adsorbed on TiO2 (110) surface based on DFT-GGA calculations utilizing periodic supercell models.A single Pd adatom on the defect-free surface prefers to adsorb at a hollow site bridging a protruded oxygen and a five-fold titanium atom along the [110] direction,while Pd dimer is located on the channels with the Pd-Pd bond parallel to the surface.According to the transition states (TSs) search,the adsorbed Pd trimer tends to triangular growth mode,rather than linear mode,while the Pd4 and Pd5 clusters prefer three-dimensional (3D) models.However,the oxygen vacancy has almost no influence on the promotion of Pd n cluster nucleation.Additionally,of particular significance is that the Pd-TiO2 interaction is the main driving force at the beginning of Pd nucleation,whereas the Pd-Pd interaction gets down to control the growth process of Pd cluster as the cluster gets larger.It is hoped that our theoretical study would shed light on further designing high-performance TiO2 supported Pd-based catalysts.     

Promoting effect of ethanol on the synthesis of N-（2-methylphenyl）-hydroxylamine from o-nitrotoluene in Zn/H2O/CO2 system

The promoting effect of ethanol on the synthesis of N-（2-methylphenyl）hydroxylamine from o-nitrotoluene in Zn/H₂O/CO₂ system was observed.By adding appropriate amount of ethanol,the selectivity of N-（2-methylphenyl）hydroxylamine increased from 71%to 90%when the reduction was carried out at 25℃under normal pressure of CO₂.     

Highly selective recognition of adenosine 5′-triphosphate against other nucleosides triphosphate with a luminescent metal-organic framework of [Zn（BDC）（H2O）2]n（BDC = 1,4-benzenedicarboxylate）

Selective recognition of adenosine 5′-triphosphate(ATP)is of great significance owing to its indispensable functions to organisms.Also,it is a challenging task because other nucleosides triphosphate hold the same triphosphate group and structurally planar bases as ATP.It is known that metal-organic frameworks(MOFs)are a new type of sensing material.In this work,highly selective recognition of ATP against other nucleosides triphosphate is successfully achieved with a luminescent MOF of[Zn(BDC)(H2O)2]n(BDC2=1,4-benzenedicarboxylate).[Zn(BDC)(H2O)2]n dispersed in water shows a remarkable redshift of the emission wavelength upon addition of ATP,while cytidine 5′-triphosphate(CTP),uridine 5′-triphosphate(UTP),and guanosine 5′-triphosphate(GTP),as well as some inorganic anions such as P2O74 or PO43 can’t induce such spectral change as ATP.1H NMR,31P NMR and Raman spectra indicate that both-stacking interactions and the coordination of Zn(II)with adenine and the phosphate group are involved in the interaction of[Zn(BDC)(H2O)2]n with ATP.In addition,the experimental results showed that the redshift extent of the emission wavelength of[Zn(BDC)(H2O)2]n has the linear relationship with the concentration of ATP in the range of 0.3–1.8 mmol/L.Based on this,the detection of ATP content in the sample of ATP injection was made with satisfactory results.This system pioneers the application of MOFs in the recognition of nucleotides,and testifies that the participation of base in the recognition process can improve the selectivity against the other nucleotides.     

溶剂热法合成用于高效光催化燃油脱氮的TiO2@MIL-101（Cr）复合材料（英文）

溶剂热合成技术是一种有效合成复合材料的技术。在本研究中,通过溶剂热法制备了不同比例复合的TiO₂@MIL-101（Cr）复合材料。并利用这些材料进行可见光光催化燃油脱氮（吡啶）。对所得催化剂采用XRD、FT-IR、SEM、TEM、BET和DRS进行表征。通过活性实验结果可以得到,20%TiO₂@MIL-101（Cr）具有良好的催化活性,在可见光光照4 h后,对吡啶的脱除率高达70%。最后,通过对HPLC-MS数据分析,得到一个光催化燃油脱氮的可能机理。     

CO2-adsorbent spongy electrode for non-aqueous Li–O2 batteries

Regulation of the Li₂CO₃ byproduct is the most critical challenge in the field of non-aqueous Li–O₂ batteries.Although considerable efforts have been devoted to preventing Li₂CO₃ formation,no approaches have suggested the ultimate solution of utilizing the clean Li₂O₂ reaction instead of that of Li₂CO₃.Even if extremely pure O₂ is used in a Li–O₂ cell,its complete elimination is impossible,eventually generating CO₂ gas during charge.In this paper,we present the new concept of a CO₂-adsorbent spongy electrode(CASE),which is designed to trap the evolved CO₂ using adsorption materials.Various candidates composed of amine functional groups(–NH2)for capturing CO₂ were screened,with quadrapurebenzylamine(QPBZA)exhibiting superior CO₂-adsorbing ability among the proposed candidates.Accordingly,we fabricated the CASE by sandwiching QPBZA between porous carbon layers,which facilitated the transport of gaseous products.The new electrode was demonstrated to effectively capture the evolved CO₂ during charge,therefore altering the reaction pathways to the ideal case.It is highly advantageous to mitigate the undesirable CO₂ incorporation in the next discharge,resulting in improved cyclability.This novel concept of a CO₂-sponging electrode provides an alternative route to the realization of practically meaningful Li–O₂ batteries.     

Synthesis and Crystal Structure of Cd（tla）（NO_3）_2［TLA＝tris（6－methyl－2－pyridylmethyl） amine］

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First-principles characterization of formate and carboxyl adsorption on stoichiometric CeO2（111）and CeO2（110） surfaces

Molecular adsorption of formate and carboxyl on stoichiometric CeO₂（111） and CeO₂（110） surfaces was studied using periodic density functional theory（DFT+U） calculations.Two distinguishable adsorption modes（strong and weak） of formate are identified.The bidentate configuration is more stable than the monodentate adsorption configuration.Both formate and carboxyl bind at the more open CeO₂（110） surface are stronger.The calculated vibrational frequencies of two adsorbed species are consistent with the experimental measurements.Finally, the effects of U parameters on the adsorption of formate and carboxyl over both CeO₂ surfaces were investigated.We found that the geometrical configurations of two adsorbed species are not affected by different U parameters（U=0,5,and 7）.However,the calculated adsorption energy of carboxyl pronouncedly increases with the U value while the adsorption energy of formate only slightly changes（<0.2 eV）. The Bader charge analysis shows the opposite charge transfer occurs for formate and carboxyl adsorption where the adsorbed formate is negatively charge while the adsorbed carboxyl is positively charged.Interestingly,with the increasing U parameter,the amount of charge is also increased.     

MIL-101(Cr)/GO复合吸附剂的O2/N2分离性能研究

变压吸附（PSA）制取O₂的核心是吸附剂.近年来,金属有机骨架（MOFs）被认为是一种具有广阔应用前景的新型吸附剂.通过水热法制备了MIL-101（Cr）/氧化石墨烯（GO）.结果表明,MIL-101（Cr）/GO-15具有更高的比表面积（3486 m²·g^-1）和更大的孔体积（2.39 cm³·g^-1）,因此也表现出更高的O₂吸附量（0.54 mmol·g^-1）.进一步根据理想吸附溶液理论（IAST）预测了其在O₂/N₂体积比为1：4混合气体中的O₂/N₂选择性为1.2,相比MIL-101（Cr）提高了17.65%.同时,MIL-101（Cr）/GO-15的循环利用性能更佳,经过三次O₂吸脱附循环后,依然拥有高达80%的O₂吸附量,具有较好的循环再生性能.     

超临界CO2中苯乙烯RAFT分散聚合

以末端带有三硫代碳酸酯的聚二甲基硅氧烷(PDMS-TTC)为大分子链转移剂,在超临界CO2中通过苯乙烯的可逆加成-断裂链转移(RAFT)聚合制备了聚二甲基硅氧烷-b-聚苯乙烯(PDMS-b-PS)嵌段共聚物,对聚合反应动力学以及产物的组成、分子量和形貌等进行了表征.由于PDMS链段可溶于超临界CO2而PS链段不溶,因此在超临界CO2中制备PDMS-b-PS嵌段共聚物的过程是以嵌段共聚物自身作为分散稳定剂的RAFT分散聚合,产物为粒径较均一的球形颗粒.     

CO2/H2O气氛下红沙泉煤中碱（土）金属的分布及其气化反应特性

使用高温气化固定床实验系统开展了CO₂/H₂O气化条件下,红沙泉煤中碱（土）金属（AAEMs）的分布情况及其对煤焦气化反应活性的影响。结果表明,气化温度低于灰熔点温度时,Na元素在煤焦表面离散分布,不存在明显的团簇富集现象;气化温度高于灰熔点温度时,Na元素在煤焦表面表现出轻微的富集现象。气化过程中K元素离散分布在煤焦表面,Ca和Mg元素在煤焦表面的富集现象比较明显,含Ca、Mg类矿物迁移团簇在煤焦表面凹陷处,形成尺寸较大的灰球,Ca、Mg元素在分布上存在一定的依赖性。气化残余焦的表观活化能和指前因子随着碳转化率的增加而增加,煤焦的反应活性变低。     

CH4 dissociation on Co（0001）: A density functional theory study

CH4 dissociation on Co(0001) surfaces is an important step, which has been investigated at the level of density functional theory. It is found that CH4 is unfavorable to adsorb on Co(0001), while CH4 favores to dissociate to CH3, CH2 and CH on Co(0001) surface by sequential dehydrogenation. In the whole process of CH4 dehydrogenation, CH4 dissociate to CH3 and H is the rate-determining step. The calculated results show that CH2 and CH exist mainly on Co(0001) surface, while the dehydrogenation of CH into C and H is difficult.     

Adsorption and Reaction of CO on Mo(100)-c(2×2)-N Surface Studied by HREELS

Molybdenum nitrides have attracted significant attention recently due to their uniquephysical and chemical properties. Many studies have shown that Mo,N is an activecatalyst for CO hydrogenation. The fundamental understanding concerning the reactionmechanisms over Mo=N. however, is not well established. The powerful surface sciencetechniques may provide an insight into the surface structure and properties of such animportant catalytic material. In previous paper', we described the results o…     

Synthesis, Crystal Structure and Fluorescent Property of One New Complex [Na2（2-benzoylbenzoato）4（Phen）2（H2O）2]·H2O

One binuclear sodium(Ⅰ) complex [Na2(2-benzoylbenzoato)4(Phen)2(H2O)2]·H2O has been synthesized with 2-benzoylbenzoic acid and 1,10-henanthroline as ligands. The crystal structure was determined by X-ray diffraction. The crystal belongs to the triclinic system with space group P , a = 1.08096(8), b = 1.09619(8), c = 1.09740(8) nm, α = 79.0600(1), β = 71.0450(1), γ = 62.0540(1)o, V = 1.08533(1) nm3, Dc = 1.421 g/cm3, Z = 2, F(000) = 484, GOOF = 1.036, the final R = 0.0363 and wR = 0.0961. The crystal structure shows that two neighboring sodium(Ⅰ) ions are linked together by two bridging water molecules, and each end position is coordinated with one 1,10-phenanthroline molecule and one 2-benzoylbenzoato to form a binuclear structure. Each sodium(Ⅰ) ion in the molecule is coordinated with five atoms to give a distorted trigonal bipyramid. The fluorescence property of the title complex is also discussed.     

A Three-dimensional Porous Metal-organic Framework Based on Cyano Unit and 1,4-Bis（1,2,4-triazol-1-yl）butane（btb）：{[Cu_8（btb）_2（CN）_8].3H_2O}_n

The title coordination polymer 1,{[Cu8(btb)2(CN)8].3H2O}n(btb = 1,4-bis(1,2,4-triazol-1-yl)butane),has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction.Complex 1 crystallizes in monoclinic,space group C2/c with a = 1.2938(3),b = 1.9422(5),c = 0.9406(2) nm,β = 121.891(4)°,V = 2.0066(9) nm3,C24H30Cu8N20O3,Mr = 1155.00,Dc = 1.912 g/cm3,μ(MoKα) = 4.209 mm?1,F(000) = 1140,GOF = 1.184,Z = 2,the final R = 0.0634 and wR = 0.1503 for I > 2σ(I).In complex 1,one-dimensional CuCN zigzag chains are linked by triazolyl groups of btb ligands to form two-dimensional networks,which are further bridged by 1,4-butyl moieties of btb ligands to fabricate a three-dimensional order framework,in which one-dimensional ellipsoid-like channels are observed.     

仪器分析综合实验:MoS2/MIL-101(Fe)的制备、表征及其光催化降解布洛芬的研究

采用溶剂热的方法制备出MoS2/MIL-101（Fe）纳米复合型催化剂,通过X射线衍射、固体紫外-可见漫反射光谱、傅里叶红外光谱、扫描电子显微镜对催化剂的结构和形态进行表征。并用该催化剂对布洛芬（Ibuprofen,IBP）进行光催化降解,采用高效液相色谱对IBP光催化降解前后的浓度进行定量分析,采用高效液相色谱-质谱联用仪对IBP光催化降解产物进行定性分析。本实验将制备复合材料的方法与多种仪器分析方法相结合,让学生了解材料制备方法及其应用的同时,着重学习了各种分析测试仪器的使用方法和基本原理。     

CO32-/Co2+/Ni2+浓度对混合相纳米Ni(OH)2物化性能的影响

以NiCl2、Co(NO3)2、Na2CO3为主要原料,采用超声波辅助沉淀法制备了混合相纳米Ni(OH)2,研究了Co掺杂比例、缓冲剂Na2CO3用量及反应物Ni2+浓度对Ni(OH)2的晶相结构、形貌、粒径及电化学性能的影响。结果表明,混合相结构的α-Ni(OH)2成分随Co掺杂比例增大而增加。较高的CO32-和Ni2+浓度有利于α-Ni(OH)2的生成。TEM测试表明,样品晶粒呈针状形态,其长径比随着Na2CO3用量增加而减小,平均粒度在60~90 nm之间。将纳米样品以8wt%与工业用微米级β球镍混合制成复合电极,其电极的放电比容量随Na2CO3用量的增加先增大后减小。当Ni2+浓度为0.4 mol.L-1、Na2CO3用量为0.5 g时,其电极(Co含量1.02wt%)的充电效率最高,放电比容量最大,0.5C倍率下高达306.9 mAh.g-1,比纯球镍电极提高30%。探讨了复合电极能较大幅度提高放电比容量的机理,提出纳米α-Ni(OH)2同时充当活化中心起催化作用的观点。     

CO2在氨基改性MIL-101(Cr)中吸附的分子模拟

采用实验与分子模拟结合的方法研究298 K下CO₂在氨基改性得到的MIL-101（Cr）-NH₂和MIL-101（Cr）-ED（ED：乙二胺）上的吸附性能。比较MIL-101（Cr）、MIL-101（Cr）-NH₂和MIL-101（Cr）-ED的吸附等温线与吸附热的结果,表明采用直接合成改性法得到的MIL-101（Cr）-NH₂比采用合成后再改性得到的MIL-101（Cr）-ED有更高的CO₂吸附容量。进一步比较密度分布图和径向密度分布曲线,分析CO₂在氨基改性MIL-101（Cr）中的吸附位,表明在低压下CO₂首先吸附在MIL-101（Cr）微孔的超级四面体中,随着吸附压力的增大逐渐填充到更大的孔中。氨基的存在增加了CO₂的吸附位点,使MIL-101（Cr）-NH₂具有较高CO₂吸附容量;同时MIL-101（Cr）-ED中的ED分子的存在增加了CO₂的吸附位点,使MIL-101（Cr）-ED也具有较高CO₂吸附容量;但是MIL-101（Cr）-ED中的ED分子占据了MIL-101（Cr）中Cr的吸附位点,使Cr对CO₂的吸附强度减弱,同时可吸附位点少于MIL-101（Cr）-NH₂,导致其对CO₂的吸附容量少于MIL-101（Cr）-NH₂。     

Visible-light deposition of CrOx cocatalyst on TiO2:Cr valence regulation for superior photocatalytic CO2reduction to CH4

Photodeposition is widely adopted for implanting metal/metal oxide cocatalysts on semiconductors.However,it is prerequisite that the photon energy should be sufficient to excite the host semiconductor.Here,we report a lower-energy irradiation powered deposition strategy for implanting CrO_x cocatalyst on TiO₂.Excitingly,CrO_x-400 implanted under visible-light irradiation significantly promotes the CH4 evolution rate on TiO₂to 8.4μmolg·^-1h^-1 with selectivity of98%from photocatalytic CO₂reduction,which is 15 times of that on CrO_x-200 implanted under UV-visible-light irradiation.Moreover,CrO_x-400 is identified to be composed of higher valence Cr species compared to CrO_x-200.This valence states regulation of Cr species is indicated to provide more active sites for CO₂ adsorption/activation and to modulate the reaction mechanism from single Cr site to Cr-Cr dual sites,thus endowing the superior CH₄production.This work demonstrates an alternative strategy for constructing efficient metal oxides cocatalysts on wide bandgap semiconductor.     

Ir/CeO2催化剂的表征和CO氧化性能

采用浸渍法制备了Ir/CeO2催化剂,考察了催化剂的CO氧化活性。随着Ir负载量的增加,Ir/CeO2催化剂的CO氧化活性先上升后下降,当Ir的负载量为1%时,催化剂的活性最高。Ir/CeO2催化剂中Ir以IrO2的形式存在,当低负载量(≤1%)时以高分散形式存在;高负载量(>1%)时以晶相IrO2的形式存在。随着Ir负载量增加,Ir粒子逐渐变大,反应比速率和反应转换频率(TOF)逐渐下降,表明小粒子上具有更高的CO反应活性。同时也发现金属态Ir催化剂的CO氧化活性高于氧化态IrOx催化剂。