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In lateral ray polydactyly, the reconstructed toe often tends to become thicker, but no standard evaluation criteria for this thickness are available. 57 patients (68 toes) with Hirai-Togashi classification type II, III, or IV whom we were able to follow-up for more than 6 months after the operation were underwent measurement of the "Reconstructed toe width to Third toe width ratio." In addition, 16 patients who could be followed up for 3 years through the mid-term course were evaluated for mid-term progress. At 6 months after surgery, the mean R/T ratio was 1.246. In patients who could be followed up for 3 years after surgery, the mean R/T ratios at 6 months after surgery and at 3 years were significantly decreased. This result suggests that the thickness of the reconstructed toe may become relatively thin in the long term.

Summary Purpose Central polydactyly of the foot is rare, with few reports on surgical methods and treatment indications. In this study, based on the experience of central polydactyly in our department, we will consider morphological classification and describe our treatment plan. Method In this retrospective study, 11 patients (11 digits) with central polydactyly were identified among 136 patients of polydactyly of the foot (2009–2018). They were classified according to morphologic characteristics: type I, the duplicated digits are independent of each other; type II, digits of the same size are duplicated; and type III, digits of different sizes are duplicated. Results In morphologic classification, there were 4 cases of type II and 7 cases of type III, but there was no case of type I. For type II, surgery was performed using the Bilhaut-Cloquet (BC) procedure in 2 patients, bone-removing flap (flap) method in 1 patient, and simple ablation in 1 patient. For type III, surgery was performed using the BC procedure in 1 patient, flap method in 3 patients, simple ablation in 2 patients, and ligation in 1 patient with floating type. Conclusion In order to obtain good cosmetic results in digits of morphologic classifications type II and III, it is necessary to select the surgical approach with careful consideration of every feature.

Summary One of the most severe complications of auricular reconstruction for microtia is exposure of the cartilage framework. Recently, negative pressure wound therapy (NPWT) has become popular for a variety of complex wounds but reports on methods for microtia reconstruction are scarce. Thus, we aimed to detail the use of NPWT for cartilage exposure in microtia reconstruction. We retrospectively analyzed 7 cartilage exposure wounds in 6 patients treated by NPWT after auricular reconstruction for microtia. All wounds appeared from postoperative days 3 to 30 with 3 on the antihelix, 2 on the helix, 1 on the triangular fossa and 1 on the scaphoid fossa. Skin defect sizes ranged from 1 to 24 mm2 and 2 cartilage frames were infected at onset. Our NPWT system was the KCI Negative Pressure Wound Therapy with V.A.C.Ⓡ GranuFoam Black™ or Silver™ and continuous suction was applied in a range of 25–125 mmHg. All wounds healed within 8 to 39 days with NPWT antecedent cases taking longer than surgery ones. All cartilage frames survived but partial cartilage atrophies remained in 4 cases. Although a secondary infection occurred in an NPWT antecedent case it was still useful as a continuous external drainage system to remove dead space exudate and stimulate granulated tissue formation. In addition to vigilance against secondary infection, surgeons should consider an additional surgical intervention if the wound fails to improve within 7 days.

Internal jugular vein thrombosis (IJVT) is a complication of neck dissection. After head and neck reconstruction, flap congestion due to IJVT may lead to flap necrosis, and early diagnosis and treatment should be considered. We experienced a case of disappearance of IJVT in which edoxaban was administered after free-flap reconstruction, and the entire flap survived. Edoxaban has few bleeding complications and was useful as a single drug approach for IJVT after head and neck reconstruction.

BACKGROUND Oral modiolus reconstruction is important in unilateral oral commissure removal including the modiolus. However, the proper procedure is not yet established. We performed free-flap reconstruction for full-thickness oral defects involving the oral commissure combined with oral modiolus reconstruction using a fascial sling. PATIENTS AND METHODS From 2008 to 2018, six oral carcinoma patients, aged 65 to 86 years, underwent free-flap modiolus reconstruction after tumor resection. The resulting lip defects of 10% to 80% were labial (two patients), buccal (two patients), and mixed (two patients). RESULTS Five anterolateral thigh flaps including one perforator and one radial forearm flap were performed. The oral defects were covered with folded flaps (size, 11 × 6-18 × 7.5 cm2 ). The orbicularis oris stumps were connected to the masseter with a fascia lata or palmaris longus tendon (length, 15-20 cm), arranged in a Y-shape in four patients and a V-shape in two patients. All the flaps survived without complications. Almost all the patients achieved good oral static effects (lip deviation and drooping) and dynamic effects (mouth opening, oral commissure narrowing, and diet) in the 6 to 65 months' follow-up. CONCLUSION Free-flap reconstruction combined with oral modiolus reconstruction using a fascial sling achieves good oral static and dynamic effects for full-thickness oral reconstruction involving the oral commissure.

We report a serious case of right ventricular wall damage during mediastinitis treatment, which was successfully treated with negative-pressure wound therapy with continuous instillation (NPWT-CI).

In digital replantation, Kirschner wire (K-wire) fixation has commonly been used for osteosynthesis. On the other hand, K-wires are often obtrusive because of protrusion from the replanted digit. We describe a case series treated using hydroxyapatite/poly-L-lactide (HPLLA) threaded pins, which are not only bioabsorbable, but also osteoconductive, for osteosynthesis in crushed amputation or comminuted fracture, including distal phalanx amputation. Using an HPLLA threaded pin, 10 digital replantations were performed between July 2016 and April 2018. The precisely cut pin is manually pushed into the fracture site as an intramedullary nail. The pin is first pushed into the distal site, and then into the proximal site, after drilling with a K-wire of the same diameter as the pin. All amputations were crush type, and levels of amputations were Tamai zone I in three cases, zone II in two and zone III in five. Eight of the 10 digits survived. The two digits that did not survive showed venous insufficiency. Bone union of the eight digits was successfully obtained after 9-19 weeks (median 12 weeks). No adverse events occurred such as distortion of the pin, infection or foreign body reaction. The HPLLA threaded pin may be an adequate device to fix fractures in digital replantation.

While there are no reports regarding dressing-associated iatrogenic skin ulcer as an adverse event of maggot debridement therapy (MDT), MDT is clinically used on patients with critical limb ischaemia with dermal fragility. Herein we report causes and counter measures for a case of iatrogenic skin ulcer induced by MDT dressing.

Ischaemic skin ulcer occurred on the foot of a 73-year-old man who had a history of fulminant myocarditis with severe cardiac dysfunction. We attempted wound bed preparation by maggot debridement therapy and salvaged his limb. It can be one of the adjuvant treatment strategies for critical limb ischaemia.

More than a half-century has passed since Maiman’s first success with ruby laser treatment. Since then, laser devices have been developed for use in diagnosis and treatment across several fields of medical practice..

Background The purpose of this study was to clarify the appropriate use of unfractionated heparin as an anticoagulation agent after digital replantation. Methods This study was a prospective, randomized, single-blind, blinded-endpoint method, three-arm, parallel-group, controlled clinical trial conducted at a single institution. A total of 88 patients (101 fingers) following digital amputation and subsequent repair by anastomosis of both arteries and veins were randomly allocated into three groups: (1) control group (no heparin dose), (2) low-dose heparin group (10,000 IU/day), and (3) high-dose heparin group (start at 15,000 IU/day, then adjust the dose to achieve an activated partial thromboplastin time of 1.5 to 2.5 times the baseline). The outcomes were assessed regarding the proportion of success at 2 weeks after replantation of amputated digits, total or partial necrosis, and occurrence of complications. Results No significant differences were found among the three groups, except for complications of congestion. The odds ratio of the heparin group compared with the control group for a success proportion was 5.40 (95 percent CI, 0.85 to 34.20; p = 0.027) in subjects aged 50 years or older. Significant elevations of activated partial thromboplastin time, aspartate transaminase, and alanine aminotransferase occurred in high-dose heparin groups on day 7. Conclusion Unfractionated heparin administration is considered effective for patients aged 50 years or older, although the routine use of unfractionated heparin is not necessary after digital replantation. Clinical question/level of evidence Therapeutic, II.

In cases of auricular surgery, postoperative dressings are thought to be important for keeping auricular contour and in helping to prevent from dressing failures due to edema or subcutaneous hematoma, which may result in fibrous or cartilaginous proliferation. However, it is often difficult to achieve success with standard dressings because of the complicated shape of the auricle. We used 2-octyl-cyanoacrylate skin adhesive to dress the auricle after different types of auricular procedures (five cases of cryptotia, two of prominent ear, two of severe auricular laceration, two of skin grafting and one of flap repair of the partial auricle defect). The 2-octyl-cyanoacrlaate skin adhesive was applied to the suture line and the operated and peripheral areas for wider coverage. No dressing materials were placed over the surface. In all cases, the desired outcome was achieved, without subcutaneous hematoma, wound dehiscence, and wound infection. Contact dermatitis caused by the skin adhesive was not observed in any of the cases. Dressing and splinting after auricular surgery can be simply and successfully achieved using 2-octyl-cyanoacrylate skin adhesive. There is no need for more complicated dressings and post-surgical dressing changes, resulting in higher patient satisfaction.

Most microsurgeons believe that smoking and severity of injury adversely affect the outcome of digital replantation surgery. As countermeasures, several pharmacologic agents have been used for the perioperative period. The purpose of this retrospective study was to examine whether the rate of necrosis is appreciably different across smokers versus nonsmokers with prostaglandin E1 therapy.The authors' study subjects included 144 patients (184 digits) who underwent replantation or revascularization between August of 2013 and August of 2015.The primary outcome was the incidence of total necrosis after replantation surgery, and the secondary outcomes were the rate of overall necrosis, proportion of total necrosis to overall necrosis, and total success. Intravenous administration of prostaglandin E1 was performed at the rate of 120 μg/day for 7 days after surgery in all patients. These outcomes of each injury type were compared between smoking and nonsmoking groups.Among the 184 injured digits, the incidence of total necrosis in smokers (23 percent) was higher than that in nonsmokers (17 percent), although no significant difference was shown (p = 0.36). The adjusted odds ratio was 1.17 (95 percent CI, 0.51 to 2.69). Similarly, there was no significant difference in the secondary outcomes between the two groups.The authors' retrospective study found no significant difference in the formation or extent of necrosis after replantation or revascularization between smoking and nonsmoking groups when all patients were treated with prostaglandin E1.Risk, II.

The structures of the supported binary sulfide catalysts, such as Ni-Mo/Al2O3 or Ni-W/Al2O3 catalysts, used in hydrotreating were analyzed by the X-ray absorption fine structure method. The catalytically active phase of the “Ni-Mo(W)-S” structure was found to decompose into bulk single sulfides, particularly when the feedstock contained large amounts of nitrogen- or oxygen-containing compounds. The active phase was able to be recovered by careful calcination of the segregated catalyst followed by sulfiding.

Background: The eyelid structure can be divided into an inner layer and an outer layer. Reconstruction of a full-thickness eyelid defect is accomplished by full-thickness composite tissue transfer or combined layered reconstruction. We present a new technique for inner layer reconstruction using ear cartilage and oral mucosa. Methods: The oral mucosa graft is harvested from the inner side of the lower lip to fit the defect size and shape. The ear cartilage graft is harvested as a rectangular strip. The harvested mucosa is sutured to the defect margin and the cartilage strip graft is interposed to the defect. Finally, the outer layer of the defect is covered with skin flaps. Consequently, the ear cartilage graft is sandwiched between the mucosa graft and the skin flap. Results: We used this technique for the reconstruction of 13 full-thickness eyelid defects of various locations, sizes, and shapes. Ten cases involved the lower eyelid, 2 cases involved the lower eyelid including the medial canthus, and 1 case involved the upper eyelid. The oral mucosa graft survived in all patients. The reconstructions were successful and there were no postoperative reports of conjunctival or corneal irritation. Conclusions: The present technique using a combination of an ear cartilage strip graft and oral mucosa graft is an easy and versatile technique for reconstruction of inner layer eyelid defects. We believe that the beneficial effects of tears, which are richly oxygenated, improved survival of the grafted mucosa.

We report a 21-year-old female patient who suddenly died of circulatory failure due to pressure from megacolon allied with pseudo-Hirschsprung’s disease. Since 3 years before her death, she had exhibited the feeling of abdominal distention, which was diagnosed as constipation. However, her constipation did not respond well to the prescribed oral administration of laxatives and enemas. She was found dead at home in the morning, lying on her back. An autopsy revealed a decreased number of ganglion cells in the rectum, suggesting hypoganglionosis. In cases of intractable chronic constipation, careful investigation of the cause of such symptoms is important.

Hydrocracking reactions of diphenylmethane and tetralin were carried out over three kinds of zeolites with or without NiW sulfide to discuss the roles of catalytic bifunctionality in two types of hydrocracking reactions. It was found that strong acid sites were not needed for the hydrocracking of diphenylmethane, while the conversion of tetralin required relatively strong acid sites. Ultra-stable Y zeolite with strong acidity exhibited high hydrocracking activity for both reactions. In contrast, mordenite catalysts did not show high activity for either hydrocracking, though isomerization of tetralin and excess hydrocracking to gaseous products proceeded. The superior performances of ultra-stable Y zeolite in the tetralin hydrocracking were suggested to be related to the hydrogen transfer ability. In most cases, the loading of NiW sulfide enhanced catalytic activity. In the diphenylmethane hydrocracking, the role of NiW sulfide was found to supply active hydrogen to the hydrocracking active sites on zeolite and to prevent polymerization of benzyl cations. In the tetralin hydrocracking, the dehydrogenated products from tetralin were re-hydrogenated over NiW sulfide.

The catalytic functionality and structural properties of three kinds of unsupported molybdenum sulfide catalysts were investigated by model test reactions and BET, TEM, XPS and XRD analyses. The results indicated that highly bent multi-layered MoS2 structures were more catalytically active, while a well crystallized MoS2 structure was more favorable for direct S-extrusion during the reactions of dibenzothiophene. It was proposed that the curvature of MoS2 basal planes was catalytically active, though they were less active for hydrodesulfurization than the edge planes.

The effects of the volume and pH of the impregnation solution and of the calcination conditions were examined on the physicochemical and catalytic properties of a 13 wt% MoO3/Al2O3 extrudate catalyst. The Al2O3 support and drying procedures (static conditions without flowing air) were fixed in the preparations. In the present series of catalysts, the amount of crystalline MoO3 was marginally small. It was found that the dispersion of Mo oxide species increased as the volume of the impregnation solution increased, gradually approaching a maximum value. The increase in pH (2–8) of the impregnation solution was found to reduce the dispersion of Mo oxide species. The Mo dispersion increased slightly for the impregnation catalysts as the calcination temperature increased (673–873 K), whereas it decreased for the equilibrium adsorption catalysts. The effects of the calcination atmosphere (with or without flowing air, or with flowing humid air) were very small on the dispersion of Mo oxide species under the present preparation conditions. On the other hand, the methanol oxidation activity of MoO3/Al2O3 was sensitive to the preparation parameters examined here. It was demonstrated by means of EPMA and XPS that a considerable migration of Mo took place during the calcination. In the present study on the preparation of a 13 wt% MoO3/Al2O3 catalyst, an impact index is proposed to measure the magnitude of the effects of the respective parameter(s) on the physicochemical and catalytic properties. With the Mo dispersion, the effects of the preparation parameter decreased in the order, surface area of the support >> drying process > volume of the impregnation solution > pH, calcination temperature and atmosphere. The size of the impact index for the dispersion of Mo sulfide species is 70–75% of that for the Mo oxide species. The HDS activity of the catalyst was less affected by the preparation parameters than the Mo sulfide dispersion. The preparation parameters affected the segregation of Mo on the outer surface of extrudates in a decreasing order: drying process > volume of the impregnation solution > pH, calcination conditions. It was found that the oxidation of methanol was affected most intensely by the drying procedures. The volume of the impregnation solution, calcination conditions and pH of the impregnation solution also strongly affected the oxidation activity. The impact index suggests that the sensitivity to the preparation variables of the physicochemical and catalytic properties of MoO3/Al2O3 decreases in the order, methanol oxidation activity > surface Mo segregation > Mo oxide dispersion > Mo sulfide dispersion > HDS activity.

In the present part of the group study on the preparation of 13 wt% MoO3/Al2O3, the effects of drying processes were investigated on the physicochemical and catalytic properties. Two series of catalysts were prepared by a conventional impregnation technique and by an equilibrium adsorption method using a common extrudate support. XPS and EPMA results demonstrated that the distribution of Mo oxide species in extrudates was strongly affected by drying processes. A rapid drying, in particular at a reduced pressure, was found to induce a strong segregation of Mo oxides on the outer surface of the extrudates, forming a sharp egg shell type distribution of Mo. On the other hand, drying under static conditions produced a moderate egg shell type distribution, suggesting that a slow drying rate is favorable for a homogeneous distribution of Mo. The equilibrium adsorption technique was found to provide considerably flat Mo profiles inside the extrudates except for the utmost surfaces where Mo concentrations increased steeply.

Ten types of 13 wt% MoO3/Al2O3 catalysts were prepared by a conventional impregnation or equilibrium adsorption method using a common extrudate support. These catalysts were subjected to a comprehensive characterization and catalytic reactions to find important preparation parameters in practical preparations. It was demonstrated in the present group study that the formation of crystalline MoO3 was strongly correlated with the Mo segregation on the outer surface of the extrudate. When the amount of the impregnation solution was large (ca. 10 cm3 g-Al2O3−1), a considerably homogeneous distribution and high dispersion of Mo oxide species were attained irrespective of the other preparation parameters. It is suggested that when a pore volume impregnation or incipient wetness technique is employed, drying processes strongly affect the dispersion and distribution of Mo oxide species. Drying at a reduced pressure is suggested to result in a segregation of Mo oxides on the outer surface of the extrudate, and accordingly a formation of crystalline MoO3.

This is the first report of a group study on the preparation of a MoO 3 /Al 2 O 3 catalyst to find predominant preparation parameters for better and reproducible catalyst preparations. Variously prepared MoO 3 /Al 2 O 3 catalysts possessing 13 wt% MoO 3 were subjected to multiprong characterizations and catalytic tests. It was found that the surface area of the support was the most predominant preparation parameter for the dispersion of Mo oxide species; the dispersion increased as the surface area of the support increased. The formation of crystalline MoO 3 was observed at a surface Mo concentration higher than 3.2 Mo nm −2 . With sulfided MoO 3 /Al 2 O 3 , it was established that the dispersion of Mo sulfide species increased with increasing surface area of the support and was in proportion to that of Mo oxide precursor species. The hydrodesulfurization activity of sulfided MoO 3 /Al 2 O 3 was proportional to the NO adsorption capacity. It is suggested that a homogeneous distribution of Mo oxide species is attained by an equilibrium adsorption technique. However, it was revealed that the surface area of the catalyst and Mo distribution were considerably modified by preparation parameters, such as drying processes, other than the surface area.

Surface structure of thin CaO layers formed on the CaF 2 (111) surface was investigated by two types of photoelectron diffraction methods. High angular resolved X-ray photoelectron diffraction (XPED) patterns indicate that two CaO domains. CaO(111) and CaO(-1-1-1), epitaxially grew and the lattice expansion occurred parallel to the surface because of the large mismatch. The change of dominant domain orientation was observed as increasing the thickness of films. We found that 8% lateral expansion and no vertical contraction occurred in 8A˚CaO layers, compared with Ca2p scanned energy photoelectron diffraction patterns and those calculated for model structures.

Excitation energy variable XPS measurements were performed using high-flux soft X-rays from synchrotron radiation. This method enables non-destructive XPS depth profiling by changing the photoelectron attenuation length. In the analysis of a HF cleaned silicon wafer, the present method revealed the presence of a very thin (∼ 1A˚) surface layer of partially oxidized silicon (Siδ+) which would not be detected by conventional Al or Mg Kα X-ray sources.

The non-radiative decay channels following the resonant photoexcitation of B 1s to π∗ of h-BN have been investigated using synchrotron radiation-excited photoelectron spectroscopy. Based on the comparison of the x ray absorption (XAS) spectrum to the constant initial state (CIS) spectrum with the initial state at the upper valence band, we have obtained a value of 0.66±0.08 for the probability for direct recombination of the exciton. This value is much higher than previously reported values for the probability for direct recombination of the Al 2p, Na 2p and Li 1s excitons.

Non-destructive depth profiling analysis with high surface sensitivity was performed by XPS with synchrotron radiation excitation. Comparison of the measured atomic ratios with the simulated ones revealed the presence of a thin Al- and Na-rich overlayer at the external surface of NaY particles. For HY zeolite particles, a gradual decrease in the Al/Si ratio from the external surface to the bulk was observed.

Two series of Ni-Mo catalysts were prepared using Al2O3 and TiO2 supports. Ni/ (Ni+Mo) ratio of the catalysts was varied, while a total metal loading of Ni and Mo was kept constant. Sulfiding conditions were optimized to give superior catalytic activities. After sulfiding, model test reactions were carried out to evaluate hydrogenation (HY), hydrocracking (HC) and hydrodesulfurization (HDS) activities of the sulfide catalysts.The highest HY activities of Al2O3 and TiO2 supported catalysts were obtained when the Ni/ (Ni+Mo) ratios were 0.25 and 0.12, respectively, showing different interaction between support and active metals. XPS measurements revealed that the atomic ratio of active metal sulfide {NiS/ (NiS+MoS2)}, which gave the highest HY activities, was 0.2 on both supports. This indicates that sulfided active metals such as NiS or MoS2 play an important role for the formation of HY active sites.Both catalysts supported on Al2O3 and TiO2 showed the highest HDS activities when the NiS/ (NiS+MoS2) ratio was 0.4. This ratio is different from that obtained in HY measurements. While HC activities of the two series of sulfide catalysts decreased with increasing of Ni loading.These results clealy show that HY, HC and HDS active sites of Ni-Mo sulfide catalysts are different each other and that proper selection of each active metal loading is required for preparing highly selective catalysts.

活性金属を組み合わせたり, 活性金属の担持量を変えることにより, Ni-W硫化物触媒の基本機能である水素化 (HY) 活性と水素化分解 (HC) 活性の制御を試みた。具体的には, 活性金属担持量の異なる一連のWおよびNi-W触媒を含浸法で調製し, 硫化後, 1-メチルナフタリンとジフェニルメタンを用いたモデルテスト反応によりHY活性とHC活性の発現挙動の検討を行った。また, 参照触媒として一連のMoおよびNi-Mo触媒を調製し, W系触媒とMo系触媒の基本活性の違いについて比較検討を行った。Ni-W触媒はW触媒と比べ極めて高いHY活性を示し, 一方, HC活性では低い値を示した。この結果は, タングステンとニッケルを組み合わせたことによりHY活性が発現し, HC活性サイトが消滅したことを示している。Ni-W触媒のHY活性とHC活性は活性金属担持量の増加とともに向上した。しかしながら, Ni-W触媒のHY活性はモノレイヤー担持領域で活性が飽和する傾向が認められた。Ni-W触媒とNi-Mo触媒を比較した場合, Ni-W触媒はNi-Mo触媒より高い反応温度で高いHY活性が得られた。また, Ni-W触媒は活性金属担持量の多い領域で高いHY活性を示した。次に, アルミナ担体の物理的および化学的性状と, タングステンおよびニッケル担持量の最適化を行い, 開発したNi-W触媒を炭化水素油中質留分の改質反応に用いた。W系触媒は原料油中の硫黄濃度の影響を受けやすいことから, 硫黄含有量の少ない石炭液化油を原料油として用いた。その結果, Ni-W触媒はNi-Mo触媒に比較してHY活性および水素化脱窒素 (HDN) 活性とも優れていることが明らかになった。

A series of nickel-containing catalysts was prepared by a sequence of impregnation and calcining steps using a γ-alumina support. The calcined catalysts were reduced in a flow of hydrogen and mixtures of hydrogen with hydrogen sulfide. Both the calcining temperature and nickel loading strongly influenced the hydrogenation activity. The changes in surface species which resulted from some of the preparation steps were identified by spectroscopy. The catalysts containing nickel without molybdenum were quickly poisoned by sulfur, but a certa in sulfur tolerance was achieved by a two-step impregnation and calcining procedure. Improved hydrogenation activity and high hydrogenation vs. hydrocracking selectivity of nickel—molybdenum catalysts were obtained with relatively low loading of molybdenum and high loading of nickel. A three-step impregnation and calcining procedure appeared to produce the most effective catalysts.

The use of catalysts for upgrading volatile matter from hydropyrolysis of Millmerran coal was investigated. The activities of Mo, W, CoMo, NiMo and NiW catalysts, all loaded on Al2O3, together with various zeolites were tested for the hydrocracking of coal volatile matter under high hydrogen pressure. The activities of the metal-loaded catalysts reached maxima at a moderate metal loading. Of all the catalysts, USY-zeolite exhibited the highest activity. The BTX yield reached 14.0 wt% (daf) or 16.7 wt% (carbon basis) at a pyrolysis temperature of 800°C and a post-cracking temperature of 600°C under a hydrogen pressure of 5 MPa.

A Ni W catalyst designed and developed for upgrading coal-derived liquids was used in 500 and 1000 h catalyst performance tests using coal-derived kerosene and gas oil, respectively. The catalyst showed considerable improvement in hydrodenitrogenation (HDN) and hydrogenation (HY) activities and less initial deactivation as compared to commercial catalysts. The catalysts used for the catalyst performance tests were characterized to clarify catalyst deactivation behavior. Precise characterization of the used catalysts by means of X-ray photoelectron spectroscopy, X-ray absorption fine structure (EXAFS and XANES), and transmission electron microscopy revealed that crystal growth of WS 2 -like structures and changes in the sulfided states and in the local structure of tungsten on the catalysts occurred during the upgrading reaction. These findings gave new insights for improving catalytic activity and the life of the newly developed catalyst.

The different structures of NiMo/Al 2 O 3 catalysts used in the secondary hydrogenation of coal-derived liquids were analyzed by the X-ray absorption fine structure (XAFS) method to clarify the catalyst deactivation mechanisms during the hydroprocessing. The XAFS analyses revealed the agglomeration of MoS 2 crystallites, as well as the decomposition of the catalytically active ‘NiMoS’ structure in the sampled catalysts. A greater amount of agglomeration was observed in the catalyst taken from the reactor exit as compared with the catalyst sampled at the inlet. Higher temperatures at the exit of the reactor presumably caused the enhanced agglomeration of the MoS 2 crystallites. On the other hand, the changes observed in the local structure around Mo and Ni due to the decomposition of the NiMoS structure were pronounced in the catalyst sampled at the inlet. Preasphaltenes found in the coal-derived liquids were speculated as the most probable cause of the decomposition.

反応原料中の硫黄化合物が硫化物触媒の核水素化 (HY) 活性と水素化分解 (HC) 活性に与える影響について検討を行った。硫化物触媒のHY活性の序列は, 反応中に硫黄化合物が存在しない場合Ni-W>Ni-Mo≫Co-Moであったが, Ni-WおよびNi-Mo触媒は反応中に硫黄化合物が存在すると, HY活性サイトが大幅に低下することがモデル反応の結果, 明らかとなった。助触媒であるNiとCoを比較した場合, Niは高いHY活性を与えるが硫黄化合物による被毒も大きいことがわかった。一方, HC活性は硫黄化合物が存在するとむしろ向上することが明らかとなり, 新しいHC活性サイトの形成が示唆された。

Thermodynamic analyses were done for better understanding of the structural changes in iron based coal liquefaction catalysts during sulfidation and oxida-tion. Chemical potential diagrams were used to evaluate the stability/reactivity of several iron phases such as Fe, Fe3O4 (magnetite), Fe2O3 (hematite), Fe0.877S (Pyrrhotite), FeS2 (phyrite), FeSO4, and Fe2 (SO4) 3. These analyses indicated that most of the iron starting materials would be converted into thermodynamically stable phase Fe0.877S under typical coal liquefaction conditions, i.e., reaction temperature of 698K under reducing/sulfiding conditions. However, the sulfidation paths were quite different in Fe2O3 and FeSO4 as the starting materials, and were influenced significantly by the sul-fidation conditions, such as temperature, P (H2S) /P (H2) and P (H2O). These analyses suggested that steaming conditions would facilitate the sulfidation, but cause the gas phase transport of hydrated compounds, which might be one of the reasons for catalyst agglomeration.

X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) using synchrotron radiation were applied for the clarification of the surface oxidation behavior of chromium nitride films which were prepared by cathode arc ion plating method. The XPS analysis of the oxidized samples demonstrated that the presence of nitrogen-containing intermediates generated N1s XPS peaks at higher binding energies than that for nitrogen in chromium nitride. In the N K-edge XAS spectra of the oxidized samples, a sharp peak assigned to 1s-π* transition was observed at a higher energy than that for the N2p-Cr3d peak assigned to chromium nitride. The above results indicate that, with replacement of the nitrogen in chromium nitride by oxygen, the released nitrogen occupies the interstitial position in the chromium oxide matrix as molecular or atomic nitrogen. A part of the interstitial nitrogen in the chromium oxide matrix is evolved from the surface with further progress of oxidation. Oxynitride species, described as CrNxOy, are not likely formed during the course of the surface oxidation.

Temperature-programmed oxidation of NiMo, CoMo and NiW hydrotreating catalysts from hydrotreatment of vacuum gas oil and coal-derived oils was carried out in thermogravimetric and fixed-bed reactors. Attempts were made to elucidate the mechanism of oxidative removal of carbon and sulfur from spent catalysts, and to investigate the structural changes of active metals and some solid-phase interactions between active metals and deposited metals during regeneration in order to correlate these resulting properties with the catalytic activities of regenerated catalysts. Changes in chemical states and structure of supported metals were analyzed by EXAFS and XPS. These structural changes were also analyzed by using the thermodynamical phase diagrams. This talk will discuss the differences in the oxidative regeneration severity between Mo and W spent catalysts, structural changes of supported metals during oxidation and following sulfidation, and effectiveness of the thermodynamics to predict a priori the regeneration and following sulfidation behavior.

水素化精製触媒の酸化再生方法最適化についての知見を得るため, 使用済みNi-W/Al2O3触媒を試料として, 再生条件の違いによる触媒活性回復挙動および再生過程における触媒構造の変化について検討した。その結果, 低酸素濃度下での多段階焼成法によって再生触媒の活性はほぼ元の活性に回復し, 大気中の一段酸化再生と比べて著しく高い活性回復が可能であることがわかった。大気中の酸化焼成は触媒上の析出炭素質除去の点では優れていたが, 急激な発熱反応が起こるためニッケル酸化物, タングステン酸化物の凝集を引き起こし, 次工程の硫化中に高活性点である"ニッケル-タングステン-硫黄"構造を生成しにくくしていることが明らかになった。以上, 本触媒の再生では酸化焼成段階の触媒成分の再分散が再生過程における最も重要な因子であると考察された。

CANMETプロセスより得られたコプロセシングオイルの灯•軽油留分についてアップグレーディング反応のあり方, およびその触媒についての検討を行った。灯•軽油留分からガソリン留分への軽質化反応は一段の反応では進行せず, 芳香環の水素化および脱ヘテロからなる第一段アップグレーディング反応と水素化されたナフテン環の開裂を行う第二段アップグレーディング反応の組み合わせが必要なことが明らかになった。アップグレーディング反応に二段階反応, 第一段反応にNi-Mo/Al2O3触媒, 第二段反応にNi-W/USY-Al2O3触媒を用いることによりコプロセシングオイルの灯•軽油留分から効率よくガソリン留分を得ることができた。また, 二段階反応によりトータルの脱ヘテロ効率も大幅に向上した。

モリブデンにニッケルやコバルトを添加したり, 活性金属の担持量を変えることにより, モリブデン系硫化物触媒の基本機能である水素化 (HY) 活性と水素化分解 (HC) 活性および水素化脱硫 (HDS) 活性がどのように変化するかを明らかにした。HY活性はニッケルを添加した場合に著しく向上し, 全ての担持領域で最も高いHY活性を示した。一方, コバルトを添加した場合, 高担持領域で高いHC活性が発現し, HY活性もMo触媒と比べ大幅に向上した。また, Ni-Co-Mo触媒のHY活性は, Ni-Mo触媒より劣るもののCo-Mo触媒より高活性であり, Co-Mo触媒と同等のHC活性を示した。HDS活性においても活性金属を組み合わせることにより, 活性がMo触媒に比べ大幅に向上した。しかし, Ni-Mo, Co-Mo, Ni-Co-Mo触媒の間で活性に大きな違いはあまり認められなかった。つぎにXAFS, TEMなどを用いモリブデン硫化物の構造を詳細に解析した結果, 担体上のMoS2状層状物がNi-Mo触媒では二次元的に, Co-Mo触媒では三次元的に成長することが観測された。これらの結果, 二次元的に成長したMoS2状層状物がHY活性の向上に, 三次元的に成長したMoS2状層状物がHC活性の向上に寄与すると示唆された。

Characterizations of soluble and insoluble products prepared from di-n-propylamine by CVD method were carried out using GC-MS and XPS methods in addition to magnetic measurements. GC-MS analysis of hexane-soluble product showed the presence of a series of aromatics with aromatic nitrile and/or heterocyclic compounds. XPS spectra of insoluble carbon product exhibited little difference in the C1s binding energy between plasma-treated and -untreated samples. However, it is found that the amorphous-like carbon content, calculated from the C1 energy loss spectra, is dependent on the plasma power and attains a maximum at 120 W, in good accordance with a plasma dependence of the apparent saturation magnetization of the carbons.

EXAFS study clarified the structure of vanadium oxide overlayers on MgO, Al2O3 and SiO2. On MgO, vanadium oxides were present as mixed oxides such as Mg3V2O8. Vanadium oxides were in the form of thin films on Al2O3 regardless of the preparation method. On the other hand, three different structures were present on SiO2; isolated species and crystallites by an impregnation method and thin films by chemical vapor deposition (CVD). The thin films on SiO2 were stable even at 773 K in air. Temperature programmed decomposition of ethanol adsorbed revealed that the dehydrogenation activities were strongly affected by the structure of the overlayers; thin films > crystallites ≫ isolated species.

硫化モリブデン触媒の水素化活性の飛躍的な向上を目的として, 助触媒として用いられるCo, NiおよびFeなどの活性金属種を有機金属錯体としてMoO3/Al2O3に担持させ触媒を調製した。モデルテスト反応の結果, 熱的に安定な金属フタロシアニン錯体を担持した場合, 水素化活性の著しい向上が認められた。この原因として活性金属種が触媒表面に高分散されること, および活性金属種が担体と複合酸化物を形成したり, 硫化され水素化活性の低下を引き起こすといった問題点が熱的に安定な有機金属錯体を用いることにより解決したことが考えられる。事実, 金属フタロシアニンの構造が触媒の焼成, 予備硫化後も維持されていることがわかった。一方, 金属フタロシアニンのみをアルミナに担持しても水素化活性が発現しなかったことから, 水素化活性の発現にはMoとCoあるいはNiといった2種類の異なった活性金属の相乗効果が必要であることも明らかとなった。また, この触媒系は高い水素化活性を示すが, 水素化分解活性が相対的に著しく低く, 反応選択性に富んだ触媒であることも併せて明らかになった。

The dispersion of molybdenum sulfide catalysts was characterized based on the lateral dimensions of MoS2 crystallites estimated by EXAFS. A new index ofN(Mo)/N(S), instead ofN(Mo), was used to estimate the average MoS2 size to minimize the contribution of the coexisting oxide or oxisulfide phase in the catalysts. EXAFS showed some advantages over other techniques, such as TEM or XPS.

4種のモリブデン系硫化物触媒 (Mo, Ni-Mo, Co-Mo, Ni-Co-Mo) の調製条件の中で, 含浸担持後の熱処理工程の違いが触媒の基本機能である水素化 (HY) 活性と水素化分解 (HC) 活性および水素化脱硫 (HDS) 活性に与える影響について検討した。その結果, 触媒の熱処理温度 (25～550°C) を変えることにより, 触媒の基本機能に違いを生じることが明らかになった。すなわち, HY活性は各触媒種とも熱処理温度が高くなるに従い増加した。一方, HC活性はHY活性とは逆に熱処理温度が高くなるに従い減少した。また, 熱処理温度は触媒のHYおよびHC活性の発現挙動に影響を与え, その影響は触媒種により異なった。HYおよびHC活性とHDS活性の関連については, Mo触媒ではHC活性とHDS活性に相関が認められ, Ni-Mo, Co-MoおよびNi-Co-Mo触媒はHC活性とHY活性に相関が認められた。反応生成物を分析した結果, Mo触媒では水素化物が相対的に多く生成することがわかった。

The effect of nitrilotriacetic acid (NTA) as a complexing agent on the sulfidation mechanisms of Co-Mo catalysts supported on activated carbon and alumina was examined by the XAFS technique. The XAFS results revealed that NTA interacted with Co atoms and formed the Co-NTA interaction, while it showed almost no influence on the local structures around Mo atoms. The Co-NTA interaction suppressed the aggregation of cobalt atoms and the interaction between cobalt and alumina during sulfiding, and consequently promoted the formation of the Co-Mo-S phase.