High Pressure Science Research Articles

Restructuring of Hydrogenation Metal Catalysts Under the Influence of CO and H2

CO and H2 structure and reactivity on single-crystal transition metal surfaces (platinum, rhodium, and palladium) were examined by surface-sensitive techniques including scanning tunneling microscopy (STM) and sum frequency generation (SFG) in high-pressure surface science studies. The studies indicated that ordered CO structures not observed in ultrahigh vacuum (UHV) can form at high pressure (10-6–103 torr). In addition, CO and H2 induce metal atom mobility and restructure the surface. On platinum, CO dissociates at high temperature (≥ 500 K), and a platinum carbonyl precursor is implicated. Concerning catalytic reactions, structure sensitive CO dissociation plays an important role in the ignition of CO oxidation, whereas CO poisons olefin hydrogenation, which becomes CO desorption limited. Lastly, solid-state hydrogen atoms are more active for hydrogenation than surface hydrogen atoms. These results suggest that spatially and temporally resolved techniques would permit molecular studies of reaction intermediates of CO and H2 in the future.

Dynamic solvent effects on the thermal cyclization of a hexadienone formed from a diphenylnaphthopyran: An example of a system with distinctly separate medium and chemical contributions to the overall reaction coordinatePreliminary results were presented at the 18th International Conference on High Pressure Science and Technology, July 23–27, 2001, Beijing, China and published as a conference paper.1

Pressure effects on the rate of thermal fading of a colored hexadienone formed from 3,3-diphenyl-3H-naphtho[2,1-b]pyran were measured at various temperatures in three highly viscous solvents, i.e., 2,4-dicylohexyl-2-methylpentane, glycerol triacetate, and 2-methylpentane-2,4-diol, as well as in their chemically similar nonviscous counterparts, such as methylcyclohexane, methyl acetate, and ethanol. Both experimental data and quantum-mechanical calculations are in agreement with formation of a cyclic activated complex. In the viscous solvents, high viscosities resulted in retardations of solvent thermal fluctuations which, in turn, slowed down the cyclization. The analysis of experimental results unequivocally demonstrated that the dynamic solvent effects in the present systems have to be described by a two-dimensional model that includes separately defined chemical and medium coordinates. Predictions of an alternative one-dimensional model with a diffusion-controlled reaction coordinate are not supported by the experimental data.

Harry George Drickamer (1918–2002): Electronic Phenomena in Condensed Matter at High Pressure

Harry George Drickamer (1918–2002): Electronic Phenomena in Condensed Matter at High Pressure

高圧力の可能性に挑む 高圧力下におけるタンパク質の結晶化

In this article, recent advances in the fundamental research in the protein crystallization under high pressure were reviewed. Pressure is expected to be an important parameter to control protein crystallization, since hydrostatic pressure affects the whole system uniformly and can be changed very rapidly. So far, a lot of studies of protein crystallization under high pressure have been done, some less systematic than others. We have particularly focused on fundamental aspects (the solubility and the crystal growth kinetics) of protein crystallization under high pressure. The studies reviewed contribute significantly to high-pressure crystallography and high-pressure protein science.

New Materials from High‐Pressure Experiments

AbstractFor Abstract see ChemInform Abstract in Full Text.

High-pressure science with a multi-anvil apparatus at SPring-8

Since first opening its doors to public research in 1997, SPring-8 has seen theaccomplishment of many important studies in a wide variety of fields through itsstable operation and cutting edge technology. High-pressure experiments havebeen carried out on a number of beamlines using a diamond anvil cell or amulti-anvil press. Here, we review the multi-anvil presses installed on theSPring-8 beamlines and a few research projects currently utilizing thistechnology. The significant difference in post-spinel boundary betweenmulti-anvil experiments and diamond anvil studies will also be discussed.

Application of synchrotron radiation and Kawai-type apparatus to various studies in high-pressure mineral physics

AbstractA combination of Kawai-type multianvil apparatus and highly brilliant X-rays at the third generation synchrotron radiation facility (SPring-8) in Japan has been successfully applied to various studies in high-pressure mineral sciences such as determinations of phase transition boundaries, P–V–T relations of high-pressure phases, kinetics of phase transitions, structure and viscosity of melts. These studies are now comfortably made at pressures of ˜25 GPa and at temperatures to 2300°C, using the intense X-ray beam and the large capacity of the high-pressure apparatus at SPring-8. Moreover, efforts have been made to further extend the pressure limit using large sintered diamond anvils. Thus in situ X-ray observations are now possible at pressures to 50 GPa with the Kawai-type apparatus, which may be doubled in the near future when the potential of sintered diamond anvils is fully utilized. On the other hand, some problems, such as those related to pressure and temperature measurement, have been manifested in these studies. These should be overcome for further quantitative studies of the mineralogy of the Earth's deep interior based on these techniques.

Harry George Drickamer

Harry George Drickamer

Equation of state of gold and its application to the phase boundaries near 660 km depth in Earth’s mantle

The pressure–volume–temperature equation of state (EOS) of gold is fundamental to high-pressure science because of its widespread use as an internal pressure standard. In particular, the EOS of gold has been used in recent in situ multi-anvil press studies for determination of phase boundaries related to the 660-km seismic discontinuity. These studies show that the boundaries are lower by 2 GPa than expected from the depth of the 660-km discontinuity. Here we report a new P–V–T EOS of gold based on the inversion of quasi-hydrostatic compression and shock wave data using the Mie–Grüneisen relation and the Birch–Murnaghan–Debye equation. The previously poorly constrained pressure derivative of isothermal bulk modulus and the volume dependence of Grüneisen parameter ( q=d ln γ/d ln V) are determined by including both phonon and electron effects implicitly: K′ 0 T =5.0±0.2 and q=1.0±0.1. This combined with other accurately measured parameters enables us to calculate pressure at a given volume and temperature. At 660-km depth conditions, this new EOS yields 1.0±0.2 GPa higher pressure than Anderson et al.’s EOS which has been used in the multi-anvil experiments. However, after the correction, there still exists a 1.5-GPa discrepancy between the post-spinel boundary measured by multi-anvil studies and the 660-km discontinuity. Other potential error sources, such as thermocouple emf dependence on pressure or systematic errors in spectroradiometry, should be investigated. Theoretical and experimental studies to better understand electronic and anharmonic effects in gold at high P–T are also needed.

New materials from high-pressure experiments

High-pressure synthesis on an industrial scale is applied to obtain synthetic diamonds and cubic boron nitride (c-BN), which are the superhard abrasives of choice for cutting and shaping hard metals and ceramics. Recently, high-pressure science has undergone a renaissance, with novel techniques and instrumentation permitting entirely new classes of high-pressure experiments. For example, superconducting behaviour was previously known for only a few elements and compounds. Under high-pressure conditions, the 'superconducting periodic table' now extends to all classes of the elements, including condensed rare gases, and ionic compounds such as CsI. Another surprising result is the newly discovered solid-state chemistry of light-element 'gas' molecules such as CO2, N2 and N2O. These react to give polymerized covalently bonded or ionic mineral structures under conditions of high pressure and temperature: the new solids are potentially recoverable to ambient conditions. Here we examine innovations in high-pressure research that might be harnessed to develop new materials for technological applications.

International Association for the Advancement of High Pressure Science and Technology (AIRAPT)

International Association for the Advancement of High Pressure Science and Technology (AIRAPT)

Research and development at rist

The Research Institute for Solvothermal Technology (RIST) opened in September, 1997 to carry out research related to high-temperature and high-pressure fluid technology. The RIST is unique institute specialized high pressure science and technology in Japan, and probably in the world. According to government, the institute is defined as the core facility of a West-Japan creative economic development base zone. Nowadays, RIST has developed new technologies using supercritical fluids, especially carbon dioxide and water, in areas related to the environment, such as the treatment of organic waste, the production of new materials, such as “new-carbon” substances, materials for batteries and electromagnetic wave absorption, and in the area of energy and resources, such as the conversion or the recycling of industrial plastic waste. A review will be given on the research and development activities at RIST. It is focused on several essential results obtained in recent investigations. Progressive joint research projects with the cooperation of enterprises, universities and government will be described.

A simple model for assessing the high pressure melting of metals: nickel, aluminum and platinum

High-pressure melting has been of general interest for our understanding of solid–liquid phase transition due to the importance in high-pressure physics and material science, and here a simple model was developed to address the high-pressure melting of metals. For this simple model, a critical volume representative for the melting point is determined compared to the reference volume. Then employing the relation of thermal pressure and temperature, the melting temperature for solids at high-pressure conditions can be easily obtained. The calculated results for nickel and aluminum and platinum indicate that this model can well reproduce the high-pressure melting of above metals, in excellent agreement with the existing experimental data. A comparison between experimental data and our calculated curves reveals that the melting under extreme compression can be better obtained by this simple model than that by previous empirical melting equations.

The Laboratory Founded by Van der Waals

During the past century, the Van der Waals Laboratory at the University of Amsterdam has been the principal provider of reliable fluid property data over large ranges of pressure and temperature. This paper describes the history of the laboratory, starting in 1898 when funding for it was obtained. In the early period, under Van der Waals and Kohnstamm, the high-pressure direction was chosen, and the first PVT and phase equilibria data were published. The main focus of this paper is the Michels period, from 1921 to 1960. In this period, the laboratory acquired its own building and assumed a unique position in the world because of its highly accurate thermodynamic, transport, and other property measurements in fluids at high pressures. In the 1950s, a second laboratory was built by Michels at the University of Maryland, per request of the U.S. Navy. Under Trappeniers, 1961–1987, the laboratory incorporated new techniques, such as NMR, undertook a major expansion of the pressure range, and extended its interest to phase transitions in molecular solids. The position of the Van der Waals Laboratory in the world of high-pressure science is highlighted.

High pressure chemistry of molecular systems: Recent experimental results and developments

It is widely recognized that relevant new chemistry is being discovered by applying high pressures. The study of the equation of state, pressure-induced phase transitions, reactivity, etc., of molecular systems are topics of increasing interest in high pressure science. This paper compiles recent studies performed by the author on molecular systems at high pressures. This includes, on the theoretical side, a reference to a universal model of EOS for both liquids and solids at high pressure. Several experiments performed by the author are also discussed; among others, a high pressure polymerization of carbon monoxide, the design of an anvil cell system developed in our laboratory, introducing an alternative Raman pressure scale when sapphires are mounted as anvils (SAC configuration) and, finally, several actual SAC experiments are presented, including examples of phase transitions and reactivity at high pressure on double and triple bonded molecular systems.

Ten Years of the Japan Society of High Pressure Science and Technology

Ten Years of the Japan Society of High Pressure Science and Technology

High-Pressure Single-Crystal Techniques

The development of apparatus to maintain materials at high hydrostatic pressure has been an active area of research for many years. From the pioneering work of Bridgman, during the early part of this century (Bridgman 1971), until the late 1960s, massive hydraulicly driven Bridgman-anvil and piston-cylinder devices dominated high-pressure science. Although there were later improvements in design, such as multi-anvil devices, it was not until the advent of the gasketed diamond-anvil cell, in the mid 1960s, that high-pressure studies were possible in non-specialized laboratories. Diamond has remarkable properties; not only is it the hardest known material it is also highly transparent to many ranges of electromagnetic radiation. Indeed incorporating these attributes, the gasketed diamond-anvil cell has become the standard tool for the generation of high pressures over the last three decades and has been applied in a wide range of experimental studies such as Brillouin scattering (Whitfield et al. 1976), Raman spectroscopy (Sharma 1977, Sherman 1984), NMR measurements (Lee et al. 1987) and, of course X-ray diffraction. It is this utility across a large range of science through physics, earth science and lately the life sciences that makes the development of the diamond-anvil cell as significant a revolution for measurement under non-ambient conditions in the physical sciences as that of the invention of the transistor to the whole sphere of electronics and computation. Figure 1. Assembly of the gasketed diamond-anvil cell: principle of pressure generation. As with all successful designs, the principles upon which the gasketed diamond-anvil cell (Van Valkenburg 1964) operates are elegantly simple (Fig. 1). The sample is placed in a pressure chamber created between the flat parallel faces (culets) of two opposed diamond anvils and the hole penetrating a hardened metal foil (= the gasket). A pressure calibrant is placed beside the sample and the free volume within …

99/01073 Coliquefaction of coal and waste plastics under milder hydrogen pressures : Yamaguchi, H. et al. Koatsuryoku no Kagaku to Gijutsu, 1998 7, (Proceedings of International Conference — AIRAPT-16 and HPCJ-38 — on High Pressure Science and Technology, 1997), 1233–1235

This chapter discusses the synergistic effects of coprocessing originated from interactions between coal and heavy oil. In a study described in the chapter, mixtures of Japanese Taiheiyo coal and Athabasca oil sand bitumen (AOB) with different coal concentrations were used as feeds. The results of the coprocessing reactions of mixtures with different coal concentration are shown. Although the original AOB contained no benzene insoluble fraction (BI), BI was produced with 5 wt% yield after the reaction of pure AOB. A mixture containing 2 wt% coals produced larger amount of HS and smaller amount of BI than the reaction of pure AOB. The addition of a small amount of Taiheiyo coal to AOB resulted in synergistic oil production by suppressing retrogressive reactions, similarly to a mixture of Forestburg Subbituminous C coal and Cold lake vacuum bottoms. With an increase in the coal concentration, the hexane soluble yield decreased, accompanied by an increase in the BI yield. Degree of hydrogen consumption for mixtures containing less than 25 wt% coal was relatively small while a serious increase was observed for mixtures containing more than 30 wt% coal.

SPring-8 Beamlines for High Pressure Science with Multi-Anvil Apparatus.

The SPring-8 will open for public use in October, 1997. Three beamlines are now under construction for high pressure research with large volume high pressure apparatus. Two multi-anvil apparatus will be installed on these beamlines. One is a 1500 ton press with a big DIA type guide-block for two stage compression, which is used for the energy dispersive x-ray diffraction study. The other is a 180 ton small DIA press similar to MAX90 at the Photon Factory, which is used for both energy and angle dispersive diffraction as well as an x-ray absorption study.

Application of scanning SQUID petrology to high-pressure materials science

High-pressure synthesis is increasingly being used in the search for new materials. This is particularly the case for superconductors1, but the synthesis products are difficult to analyse because they are small in size (∼50 mg) and often consist of a mixture of unknown phases exhibiting a low superconducting volume fraction. X-ray or electron diffraction cannot identify a superconductor unambiguously if it is a minority constituent. Here we report a methodology—‘scanning SQUID petrology’—that combines the use of a scanning SQUID microscope2 with petrological techniques to image and identify low concentrations of superconducting phases in complex phase assemblages. We demonstrate the power of this methodology by investigating the poorly understood origin of superconductivity in the high-pressure Sr–Cu–O system1. A Sr2CuO3 + KClO3 diffusion couple3 processed at 60 kbar and 950 °C yielded the superconductor Sr3Cu2O5Cl at the ∼3% level adjacent to the oxidizer. In addition to the unexpected participation of chlorine from an ostensibly ‘inert’ oxidizer that is commonly used in high-pressure synthesis work, the sample was highly zoned owing to limited oxygen diffusion kinetics, and contained non-superconducting Sr2CuO3.2. These contamination and diffusion problems probably affected all previous high-pressure copper oxide diffusion-couple experiments. Scanning SQUID petrology has general applicability to heterogeneous samples and is capable of detecting magnetic or superconducting phases at concentrations of less than 1 p.p.m.