X-ray diffraction and X-ray photoelectron spectroscopy studies of Ni-P deposited onto carbon fiber surfaces: impact properties of a carbon-fiber-reinforced matrix

In this work, the Ni-P coating on carbon fiber surfaces was carried out in order to improve the impact resistance of carbon fibers-reinforced epoxy matrix composites. The fiber surfaces and the fracture behaviors of composites were measured in terms of X-ray diffraction spectrometry (XRD), X-ray photoelectron spectrometry (XPS), scanning electron microscopy (SEM), and falling weight impact testing. From the XRD and XPS measurements, it was observed that Ni-P coating of carbon fibers led to an increase in two phases, i.e., microcrystalline and amorphous, mainly due to the increase of NiP(2), Ni(3)P, and Ni metal. Energy adsorbed by composites through the various fracture mechanisms was seen to be the characteristic distinguishing between nontreated and treated fiber-reinforced composite systems. The Ni-P alloy technique to improve the impact resistance of the composites was shown to be the modification of fiber-epoxy resin interfaces.     

CeO2-TiO2复合氧化物的制备、表征及其对CO氧化的催化性能

采用溶胶-凝胶法制备了一系列不同n(Ce)/n(Ti)的CeO2-TiO2复合氧化物,对复合氧化物的物相结构、形貌特征、比表面积和氧化还原性质进行了表征,并考察了复合氧化物对CO氧化反应的催化性能.结果表明,n(Ce)/n(Ti)>0.10时,复合氧化物为无定形结构;n(Ce)/n(Ti)=0.10~0.30时,复合氧化物失去CeO2和TiO2各自的特征,形成CeO2-TiO2固溶体,具有较大的比表面积.CeO2-TiO2复合氧化物本身对CO氧化反应的催化活性不如TiO2或CeO2的高,但Pd/CeO2-TiO2比Pd/TiO2或Pd/CeO2具有更高的催化活性.     

Effect of 3-Amino-5-mercapto-1,2,4-triazole on Electroless Nickel Deposition

The effects of organic additive, 3-amino-5-mercapto-1,2,4-triazole （AMTA） on bath stability, deposition rate, reaction activation energy, and Ni-P coating composition in acidic electroless nickel plating were investigated. Polarization curve method and infrared reflection spectroscopy were used to analyze the mechanism of the effect of AMTA on electroless nickel deposition. It was observed that AMTA improved bath stability, decreased the deposition rate, and increased the reaction activation energy. It was also revealed that AMTA decreased the phosphorus content and increased the sulfur content in Ni-P coating. In addition, AMTA inhibited the anodic oxidation of hypophosphite and accelerated the cathodic reduction of Ni^2＋. Infrared reflection spectroscopy result indicates that AMTA was adsorbed on the surface of Ni-P and interacted with Ni^2＋ to form an AMTA-Ni^2＋ compound. On the basis of the results of this study, the mechanism of the effect of AMTA on electroless nickel deposition was deduced.     

超细非晶镍合金的化学制备及类金属元素对性质的影响

常温下分别使用KBH4和NaH2PO2在水溶液中还原Ni^2^+制得了Ni65B35和Ni89P11超细非晶合金(UFAAP), 同时使用KBH4和NaH2PO2还原Ni^2^+制得了Ni73P13B14UFAAP. Ni-P的粒径较大, 约为110nm, Ni-B的粒径较小, 约为20nm,Ni-P-B的粒径居其之间, 约为40nm。XPS表明, Ni-P间的相互作用强于Ni-B间的相互作用, Ni-P-B中P的电子状态与Ni-P中的相似。Ni-P-B比Ni-P的比表面积高得多,Ni-P-B比Ni-B和Ni-P具有更好的非晶态稳定性, 在573K热处理, 它的非晶态保持完好。晶化结果也表明Ni-P-B中Ni-P间的相互作用比Ni-B间的强。     

On the formation of the interlayer between Ni-P coating and AZ33 magnesium alloy substrate by means of in situ SEM observation

Pre-treatment process is the key step for electroless plating. Once a suitable pre-treatment film is in place, the desired metals can be plated. In this paper, Ni-P coating was successfully prepared on AZ33 magnesium alloy with Mg（OH）2 pre-treatment film by electroless plating. To investigate the role of MgF2 in Ni-P coating, the deposition procedures between Mg（OH）2 pre-treatment film and Mg（OH）2-MgF2 pre-treatment film （a traditional process） were compared. The surface morphology variations of coatings were observed with scanning electron microscopy and the compositions were analyzed by energy dispersive spectrometry. The results showed that during the plating, both MgF2 and Ni-P deposited at the initial stage, and MgF2 distributed in the bottom of the coating, forming a transitional interlayer with Ni- P. According to the heat quench test, a poor adhesion of the coating mainly occurred between the MgF2 and Ni-P coating.     

CeO2和Pd在Ni/γ-Al2O3催化剂中的助剂作用

采用脉冲微反技术研究了添加n型半导体氧化物CeO2及贵金属Pd对Ni/γ Al2O3催化剂上CH4积炭/CO2消炭反应性能的影响,并运用BET、TPR、CO2 TPSR及氢吸附等技术对催化剂进行了表征.结果表明, n型半导体氧化物CeO2的添加可以降低Ni/γ Al2O3催化剂上CH4裂解积炭活性,提高CO2消炭活性,添加少量贵金属Pd可以进一步改变载体Al2O3、助剂CeO2和活性组分Ni之间的相互作用,从而改善Ni/γ Al2O3催化剂的抗积炭性能.通过Ni Ce Pd/γ Al2O3催化剂上CH4积炭/CO2消炭模型对上述作用机制作出了新的解释.     

Quantum Chemical Study on Geometry and Property of Cluster Ni_4P

1INTRODUCTION Amorphous alloys attractive to scientists have worked in the field of materials and catalysts since they have many excellent physical and chemical pro-perties,such as high magnetic susceptibility,high specific heat,high strength,ductile in compression,low coefficient of friction,high corrosion resistance,super plasticity within the range,ferromagnetism and super conductivity[1~5].Especially,amorphous alloys as catalytic materials have shown either hig-her activity or selectiv…     

Controlled synthesis, characterization, and crystallization of Ni-P nanospheres

The size- and composition-controlled synthesis of Ni-P nanospheres from nickel chloride and sodium hypophosphite has been systematically investigated by changing the conditions, such as the ratio of the starting materials, pH value, and reduction temperature. It was found that when the starting ratio of H2PO2(-)/Ni2+ was changed the size and chemical composition of the nanoparticles changed simultaneously. Within a suitable pH range, the phosphorus content was altered without affecting the particle size. Increasing the reduction temperature resulted in smaller Ni-P nanospheres but invariable phosphorus content. The Ni-P nanospheres were amorphous when the phosphorus content was higher than 10.0 mol %, while lower phosphorus content led to a composite of amorphous Ni-P and face-centered cubic (fcc) Ni. During postsynthesis calcinations, amorphous Ni-P nanospheres with a low phosphorus content directly crystallized to Ni3P and fcc Ni. However, the specimens with high phosphorus content crystallized via some intermediate phases such as Ni5P2 and Ni12P5. In the latter, an amorphous P-rich shell was developed simultaneously. A preliminary catalytic test of growth of carbon nanofibers on the Ni-P nanospheres has been carried out.     

Characterization and Catalytic Properties of a Rapidly Quenched Ni-RE-P-AL Catalyst

IntroductionAmorphous.alloy has been found to have superior catalytic properties["']. However, asan applied catalyst, its small surface area and low thermal stability during the catalytic processare the encountered problems usually.In the previous study, we found that addition of a small amount of rare earth element effectively stabilized the amorphous phase in a Ni--P alloyL'~'j, and the surface area of the amorphous Ni--RE--P alloy could be greatly enlarged by introducing Al into the Ni-…     

Oxidative carbonylation of phenol with a Pd-O/CeO2-nanotube catalyst

CeO2 nanotubes (CeO2-NT) were synthesized using carbon nanotubes as template by a liquid phase deposition and hydrothermal method. X-ray diffraction, transmission electron microscopy, and N2 adsorption-desorption were used to characterize the CeO2-NT. The wall of CeO2-NT was composed of small interconnected nanocrystallites ranging from 4 to 9 nm in size. The specific surface area of CeO2-NT was 108.8 m2/g with an outer diameter of 25 nm and length > 300 nm. Supported Pd cata-lyst, Pd-O/CeO2-NT, was prepared using CeO2-NT as the support. Temperature-programmed reduc-tion analysis showed that the surface oxygen on Pd-O/CeO2-NT could be reduced at low tempera-ture, therefore it showed high activity in the reaction. Pd-O/CeO2-NT was used as the catalyst for the oxidative carbonylation of phenol. It has better activity and DPC selectivity than Pd-O/CeO2-P, which was prepared by supporting Pd on zero dimensional CeO2particles. Under the optimized conditions, phenol conversion was 67.7% with 93.3% DPC selectivity with Pd-O/CeO2-NT. However, its catalyt-ic activity decreased when the catalyst was used for the second time. This was attributed to the destruction of the tubular structure of Pd-O/CeO2-NT and Pd leaching during the reaction.     

化学镀Ni-P合金在CO2溶液中的腐蚀磨损行为

研究了化学镀Ｎｉ－Ｐ合金在ＣＯ２溶液中的腐蚀磨损行为。结果表明,ＣＯ２浓度增大,载荷增加,滑动速度增加,化学镀Ｎｉ－Ｐ合金的腐蚀磨损速率增大、自腐蚀电位负移;ＣＯ２浓度增大,载荷减小,滑动速度降低,化学镀Ｎｉ－Ｐ合金的摩擦系数增大。同样条件下,化学镀Ｎｉ－Ｐ合金比Ｇ１０５钢具有更高的耐腐蚀磨损性。     

Ni-B/SiO2非晶态催化剂应用于硝基苯液相加氢制苯胺

 考察了Ni－B／SiO2非晶态催化剂在高压液相硝基苯加氢制苯胺反应中的催化活性和选择性．研究表明,该催化剂不仅具有很高的催化活性,而且对苯胺的选择性较高,优于RaneyNi以及其它Ni基催化剂．晶化导致催化剂失活．载体的存在不仅能提高催化剂的分散度,而且能对非晶态结构起稳定化作用;将催化剂保存在乙醇中可保持其活性不变．结合催化剂的表征,讨论了Ni－B／SiO2非晶态催化剂的催化性能与其结构的关系．     

非晶态金属合金作催化材料的研究V. Ni-W-P非晶态合金微粒催化加氢活性研究

首次用化学还原法制备了非晶态Ni-W-P合金微粒。应用X射线衍射(XRD)、差热分析(DSC)、透射电子显微镜(TEM)和X射线光电子能谱(XPS)等方法对该微粒进行了表征。考察了该微粒催化环戊二烯加氢的活性, 并与Ni0P非晶态合金对比, 发现少量的W的加入改变了Ni-P的加氢活性。     

钇和柠檬酸对非负载磷化镍催化剂加氢脱硫性能的影响

采用传统程序升温(TPR)法制备了稀土金属钇(Y)或柠檬酸(CA)改性及Y和CA同时改性的非负载型Ni2P催化剂;采用X射线衍射(XRD)分析、N2吸附比表面积(BET)测定、CO化学吸附分析、X射线光电子能谱(XPS)和透射电子显微镜(TEM)对催化剂的结构和性质进行了表征;并考察了Y和CA对催化剂上进行的二苯并噻吩(DBT)加氢脱硫(HDS)反应性能的影响.结果表明,Y和CA均可促使非晶相NixPyOz向磷化镍活性相的转化,抑制Ni_5P_4杂晶相的形成,从而促进Ni2P活性相的生成;同时能够丰富催化剂的孔道,抑制催化剂表面磷的富集,得到更好的孔结构、更高的活性相分散度.Y或CA以及两者同时改性后的催化剂DBT转化率均明显高于Ni-P催化剂.各催化剂的HDS活性大小顺序为Y-Ni-P-CANi-P-CAY-Ni-PNi-P.在340℃,3.0 MPa,氢油体积比700,质量空速(WHSV)1.5 h-1的条件下,Y-Ni-P-CA催化剂的DBT转化率为97%,比Ni-P催化剂提高了约35%.     

氮气气氛下焙烧的CeO_2载体负载Ni基催化剂的顺酐加氢性能研究

在氮气气氛中合成了具有较高氧缺陷浓度的CeO_2载体,采用浸渍法制备了Ni含量为10%的Ni/CeO_2-N催化剂,考察了其顺酐液相加氢性能,并与氧气气氛中制得的CeO_2载体负载Ni催化剂作了对比.N_2低温物理吸脱附,X-射线衍射,拉曼光谱,H_2程序升温还原等表征手段表明,在氮气气氛中合成的CeO_2具有较高浓度的氧缺陷位,在催化剂还原过程中可促进NiO物种的还原,同时在催化剂表面生成更多的氧缺陷位.该氧缺陷位可与活性金属Ni物种协同作用,显著提高催化剂的C=C及C=O加氢活性.     

PROMOTING EFFECT OF RARE EARTH OXIDES ON Ni/Re_xO_y-Al_2O_3 CATALYST FOR PARTIAL OXIDATION OF METHANE TO SYNTHESIS GAS

IntroductionSynthesisgas(HZ CO)isproducedfrommethanemoshybysteamrefonningwhichsuffersfromlimitationssuchasveryhighenergyrequirements,complicatedequipmentandinstallations,highHZ/COproductratioandpoorselectivityforcarbonmonoxide.Recently,manyresearchershave…     

加速剂对化学镀镍层组成与结构的影响

加速剂对化学镀镍层组成与结构的影响方景礼，武勇，韩克平，张敏（南京大学应用化学研究所配位化学国家重点实验室南京２１００９３）关键词化学镀镍，Ｎｉ０Ｐ合金，加速剂，硫脲化学镀镍磷合金具有耐蚀性、可焊性、厚度均匀和硬度高等优点，已得到广泛应用。为提高生产...     

Electrochemical characteristics and interfacial contact resistance of Ni-P/TiN/PTFE coatings on Ti bipolar plates

The Ni-P/TiN/PTFE (poly tetra fluoroethylene) composite coatings were prepared by electroless plating method on Ti plate, which was used as bipolar plates of proton exchange membrane fuel cells (PEMFCs). The morphology, crystallographic texture, electrochemical corrosion, contact resistance, and hydrophobic property of the Ti bipolar plates with coatings were investigated. The results revealed that Ni-P/TiN/PTFE coating had a dense surface morphology, uniform distribution of composite particles. Ti with coating showed 0.48 μA cm² of corrosion current in the simulated solution of PEMFCs and 6 mΩ cm² of interfacial contact resistance (ICR). The hydrophobicity test showed that the coating interface was flat and the wetting angle was 112.4°. In conclusion, The Ni-P/TiN/PTFE composite coatings exhibit superior improvement in corrosion resistance, interface hydrophobicity, and conductivity to Ni-P, Ni-P/TiN, and Ni-P/PTFE coatings. The Ni-P/TiN/PTFE coating was suited for bipolar plate surface modification of bipolar plates.     

液体和非晶态NiAl3合金结构的从头算分子动力学模拟

应用从头算分子动力学方法模拟了液体以及淬冷形成的NiAl₃合金体系,得到了它们的对相关函数、结构因子、键对分析信息.结果分析表明,在淬冷条件下得到的体系呈现非晶态性质,且非晶态结构类似于液态NiAl₃合金的结构,可以用液体结构近似描述非晶态性质.还进行了电子结构分析,得到液体NiAl₃合金的电子态密度和电荷分布.在液体镍铝合金中,镍为电子受体,部分电子由铝向镍转移,支持了Candy等人的XPS实验结果.镍铝间强烈作用,形成带有弱共价键性质的金属键.镍在合金中相当分散,这能部分解释由淬冷形成的NiAl₃合金制得的骨架镍催化剂活性增强的原因.     

非晶态Ni-W/ZrO2复合镀层的制备、热处理及腐蚀行为

在镍钨合金电解液中, 通过搅拌使二氧化锆固体微粒悬浮, 电沉积制备Ni-W/ZrO2复合镀层. 研究结果表明, 二氧化锆粒子影响复合镀层的电沉积、表面形貌、结构、热处理过程和抗腐蚀性能; 与Ni-W合金的电沉积过程相比, 复合镀层中的W含量和电流效率均降低; 在400 ℃处理1 h后, 嵌入Ni-W本体中的ZrO2粒子脱落, W向镀层表面富集. 扫描电子显微镜(SEM)结果显示, 复合镀层呈现团粒状形态, 无裂纹. 差示扫描量热(DSC)分析结合X射线(XRD)衍射实验指出, Ni-W/ZrO2复合镀层为非晶态结构. 复合镀层的显微硬度较纳米晶Ni-W合金的高; 热处理后, 复合镀层的显微硬度和在3%氯化钠溶液中的抗腐蚀行为显著增强.