Influence of the phosphorus source on iron phosphide nanoparticle synthesis for hydrogen evolution reaction catalysis

Iron phosphide (FeP) is in the spotlight as a hydrogen evolution reaction (HER) catalyst due to its cost efficiency, good catalytic activity, and stability within a wide pH range. However, there is still a need to synthesize FeP nanoparticles (NPs) with systematic analysis to improve their catalytic activity. Herein, we report FeP NPs synthesized with various phosphorus sources (TOP, trioctylphosphine; TPP, triphenylphosphite; TEAP, tris(diethylamino)phosphine; and TBP, tri-n-butylphosphine) via phosphorization reaction. We clearly demonstrate that the HER activity of the catalyst based on the FeP phase is dependent on the choice of phosphorus source used in the colloidal NP synthesis. Among the samples, FeP NPs synthesized with TPP achieved the highest HER activity with an overpotential of 76 mV at 10 mA cm⁻² in 0.5 M H₂SO₄. Our results reveal a critical aspect of colloidal synthesis to achieve enhanced catalytic activity in the synthesis of transition metal phosphide NPs.     

Interface enhancement of carbon nanotube/mesocarbon microbead isotropic composites

Carbon nanotubes (CNTs) are incorporated into mesocarbon microbead (MCMB)-derived isotropic graphite to improve their mechanical properties. CNTs are homogenously distributed on the MCMB surface by acid-treatment and mechanical mixing. The composites are prepared by cold isostatic pressing, carbonization, and graphitization. The mechanical properties and isotropy ratios of the CNT/MCMB composites are determined by four-point bend tests and thermal expansion measurements, respectively. The addition of CNTs improves the flexural strength by ca. 20%, while keeps a low isotropy ratio. CNTs dispersed on particle interfaces improve the interfacial strength, this reinforcing mechanism is confirmed by a fracture mode analysis with scanning electron microscope.     

钻井工程数据库的扩展与深化

目前的钻井工程数据库标准历经15年,依旧发挥着积极作用,同时新技术和新需求的出现,也催化标准与时俱进。在此背景下提出扩展与深化钻井数据库标准的设计原则,进而探讨了对若干数据库技术细节的处理方法,最后指出了推进这一标准化工作的要点。从统观的角度思考新的钻井信息化建设,为行业的标准化提供参考。     

Preparation and optical properties of iron-modified titanium dioxide obtained by sol–gel method

In this paper twelve TiO₂:Fe powders prepared by sol–gel method were analyzed being into consideration the kind of iron compound applied. As a precursor titanium (IV) isopropoxide (TIPO) was used, while as source of iron Fe(NO₃)₃ or FeCl₃ were tested. Fe doped TiO₂ was obtained using two methods of synthesis, where different amount of iron was added (1, 5 or 10% w/w). The size of obtained TiO₂:Fe particles depends on the iron compound applied and was found in the range 80–300 nm as it was confirmed by SEM technique. TiO₂:Fe particles were additionally investigated by dynamic light scattering (DLS) method. Additionally, for the TiO₂:Fe particles UV–vis absorption and the zeta potential were analyzed. Selected powders were additionally investigated by magnetic force microscopy (MFM) and X-ray diffraction techniques. Photocatalytic ability of Fe doped TiO₂ powders was evaluated by means of cholesteryl hemisuccinate (CHOL) degradation experiment conducted under the 30 min irradiation of simulated solar light.     

Continuous monitoring of concrete E-modulus since casting based on modal identification: A case study for in situ application

An in situ application of a recently developed technique for continuous measurement of concrete E-modulus since casting is addressed in this paper. Such technique is based on the continuous modal identification of a composite beam that contains the material under test. As concrete hardens, the flexural resonant frequency of the beam increases and the computation of E-modulus can be made with recourse to the beam’s equation of motion. Even though recent publications have shown the feasibility of this technique in laboratory environment, no actual in situ application has been tested so far. That is one of the topics of this paper, which also proposes improvements to the originally devised method and compares results with ultra-sound wave velocity measurements. The scope of the work is extended with the modal analysis of a prefabricated beam made of the same concrete under test, allowing insights to be made regarding the E-modulus of concrete.     

Vm/MOx催化剂对柴油碳烟催化燃烧抗硫中毒性能的比较

用柠檬酸络合助溶的等体积浸渍法制备了不同载体(γ-Al2O3 、SiO2 、TiO2、ZrO2和CeO2)负载的系列钒氧化物催化剂,使用红外光谱对催化剂硫中毒老化后的结构进行表征,采用程序升温氧化反应技术评价了硫老化后的催化剂对柴油碳烟催化燃烧的活性.结果表明,负载钒基氧化物催化剂硫老化后,催化剂表面主要以亚硫酸盐物种...     

知识库在地铁车载ATO控制中的应用

针对知识库在地铁车载ATO控制中的使用提出了一种可行的应用方法,以实例的方式详细描述了ATO知识库的设计原理和知识库的获取及更新方法,为实现ATO的人工智能控制奠定了基础.     

活性炭负载型催化剂的制备及其在渣油加氢中的应用

渣油加氢工艺是一项重要的渣油深度转化技术,高性能渣油加氢催化剂的研发是其核心。本文介绍了一种新型渣油加氢催化剂——金属/活性炭负载型催化剂,从催化剂制备方法、反应活性、活性相等多个方面,阐述了其在渣油加氢中的应用研究情况。提出应该从增强催化剂机械强度、改进催化剂成型工艺、提高催化剂稳定性等方面改进催化剂的性能。     

连续碳化硅长丝纤维生产技术现状

连续碳化硅长丝纤维是目前具有最高比强度和最高比模量,以及高热稳定性的人造纤维。其生产技术发展经历了从高含氧量到超低含氧量,从微量元素掺杂到多种元素掺杂复合连续碳化硅长丝纤维几个关键技术阶段。连续碳化硅长丝纤维生产的4个关键技术工艺过程包括：有机硅烷小分子单体经化学或催化聚合形成有机聚硅烷（Polysilanes,PS）的聚合过程;PS的粘溶液或熔浆在惰性气氛中机械纺丝制造PS原丝的工艺过程;PS原丝经过在惰性化学气氛中控温化学转化形成聚碳硅烷（Polycarbosilanes,PCS）纤维及同时发生交联的热化学转化过程;PCS纤维在惰性以及／或者反应性气氛中高温热交联结晶化形成终烧碳化硅纤维的高温热化学转化过程。熟悉并完全掌握每一个工艺过程的技术关键,才能有效选择合适的工艺及生产装备,生产出高强度高模量连续碳化硅长丝纤维,为我国航空航天以及高端制造业提供高品质连续碳化硅长丝纤维材料。     

相同晶貌不同硅铝比ZSM-5的合成及其催化裂化性能研究

ZSM-5分子筛被广泛用于流化催化裂化过程以提高产品性能和选择性,尤其是提升汽油辛烷值和增产低碳烯烃如丙烯等,而系统地探索ZSM-5分子筛属性和产品选择性之间的结构-性能关系的研究尚不够深入。根据现有ZSM-5分子筛广泛运用的特点,针对丙烯选择性尚待提高的现状,通过严格控制化学合成与制备条件,考察ZSM-5分子筛的某些特性对其自身稳定性、水热稳定性、酸性、比表面积和孔道性质等影响,进一步研究对ZSM-5分子筛丙烯选择性的影响,为ZSM-5分子筛对丙烯增产针对性的提升和实际应用提供技术支持。利用晶种法,制备了具有相同晶貌、晶粒大小约2.5 μm、大小高度均一和硅铝物质的量比分别为60、80、120、200和300的系列ZSM-5分子筛,通过XRD、SEM和NH₃-TPD等研究其物化性质,并制备成催化裂化助剂,利用ACE和真实原料对助剂的催化裂化性能进行考察,结果表明,ZSM-5分子筛硅铝物质的量比为80~100时,可以获得较高的丙烯选择性,相对于空白样品丙烯产量约增加2个百分点。