里川 重夫

For the development of small-scale desulfurization processes such as fuel cell systems, catalytic decomposition of dimethyl sulfide (DMS) to H2S without H2 addition was investigated using a Co/H-Beta zeolitic catalyst, with its acidity controlled via post-synthesis modification. The protonated zeolite (H-Beta) exhibited little catalytic activity at 400 °C, but Co modification significantly promoted DMS decomposition, with a high H2S yield of 50% observed. The optimum Co amount was equivalent to half of the ion-exchange capacity of the original H-Beta zeolite. While the Co/SiO2 did not display catalytic activity, and thus, the coexistence of acid and Co ion sites is necessary in DMS decomposition. The Co species were introduced at the cation sites of the zeolite, suppressing Co sulfurization, which contributed to the high catalytic activity.

This study focused on evaluating the catalytic properties for the reverse water gas shift reaction (RWGS: CO2 + H-2 -> CO + H2O Delta H-0 = 42.1 kJ mol(-1)) in the presence of hydrogen sulfide (H2S) over a Fe/CeO2 catalyst, commercial Cu-Zn catalyst for the WGS reaction (MDC-7), and Co-Mo catalyst for hydrocarbon desulfurization. The Fe/CeO2 catalyst exhibited a relatively high catalytic activity to RWGS, compared to the commercial MDC-7 and Co-Mo catalysts. In addition, the Fe/CeO2 catalyst showed stable performance in the RWGS environment that contained high concentrations of H2S. The role of cofeeding H2S was investigated over the Fe/CeO2 catalyst by the temperature programmed reaction (TPR) of CO2 and H-2 in the presence of H2S. The result of TPR indicated that the co-feeding H2S might enhance RWGS performance due to H2S acting as the hydrogen source to reduce CO2.

A supported ruthenium catalyst (Ru/Cs+/CeO2) for ammonia synthesis is described which incorporates a large amount of a Cs+ promoter in a porous CeO2 support to enhance the electron donation effect of the alkali promoter on the ruthenium catalyst. Optimization of the Ru and Cs+ promoter contents improves the ammonia synthesis rate to more than 4 times that of the benchmark catalyst (Cs+/Ru/MgO) at 350 degrees C and 0.1 MPa, and the ammonia synthesis rate is stable for 100 h. Introduction of the Cs+ promoter into the support before the Ru impregnation increases the particle size of the Ru catalyst. Despite a decrease in the number of active sites, the TOF of the catalyst is more than 50 times that of Ru (2 wt%)/CeO2. CO adsorption measurements suggest an electron donating effect by the Cs+ promoter to ruthenium metal. Reaction order analysis indicates this is due to a mitigation of hydrogen poisoning. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Three-way catalytic converters are widely used to regulate emissions from gasoline-powered vehicles. Although significant effort over the past 40 years has resulted in the discovery of several metal additives that improve the thermal stability of three-way catalysts (TWCs), their effects on the actual catalytic process have not been studied systematically. The present work examines the roles of the typical basic metal additives La, Ba, and Sr in Pd-based TWC systems, using various spectroscopic and kinetic studies. Metallic Pd-0 species on Sr/Al2O3 and Ba/Al2O3 supports were found to be more electron-rich than those on pristine Al2O3, whereas those on La/Al2O3 were more electron-deficient. Consequently, Pd/La/Al2O3 showed a lessened CO poisoning effect during NO reduction reactions. Evaluations were performed using powdered catalysts as well as monolithic honeycomb catalysts under conditions simulating actual use. Pd/La/Al2O3 was observed to promote the catalytic reduction of NO most efficiently, while Pd/Ba/Al2O3 exhibited the highest activity for the oxidations of CO and C3H6. The present data suggest that the optimal metal additive for a Pd-based TWC will be determined by the specific application. The selection of such metals should take into account not only the stability but also the promotional effect during the exhaust purification process. (C) 2021 Elsevier Inc. All rights reserved.

<p>Pt/MoO_x/TiO₂ shows excellent catalytic performance for the reverse water-gas shift reaction at 250 °C <italic>via</italic> reverse Mars–van Krevelen mechanism.</p>

© 2019 Elsevier Ltd Carbon fiber reinforced plastics (CFRP) are desirable owing to their high specific strength and rigidity. Traditional recycling methods for these products such as thermal decomposition cause considerable damage to the carbon fibers. In search for better recycling methods, we explored the use of electrical treatment for the separation of resin. Herein, we investigated the effects of annealing on the separation of resin from a CFRP cross-ply laminate molded from unidirectional prepreg (carbon fiber/epoxy) using electrical treatment. The annealing of the CFRP cross-ply laminate [0°/90°]2s was performed at temperatures ranging from 60 °C to 450 °C, followed by the electrical treatment. Experimental results demonstrated that the separation of resin, without the carbon fiber damage, could be achieved by annealing at temperatures close to the epoxy decomposition temperature. For the non-annealed CFRP specimens, the separation of resin was achieved with considerable damage to the carbon fibers.

© 2019 Elsevier B.V. Removal of epoxy resin from a unidirectional carbon fiber reinforced plastic (CFRP) laminate was achieved with an electrical treatment. The treatment was carried out using a two-electrode cell with the CFRP laminate as the anode, and the effect of applying a high voltage was investigated to reduce the treatment time. The results showed that a high voltage in the electrical treatment leads to high weight loss of the unidirectional CFRP laminate. In the digital microscope images of the residue obtained from the electrolyte after the treatment, fragments assumed to be resin were observed. The removal mechanism involved an electrochemical reaction; however, no decomposition product related to the resin was detected in the electrolyte after the treatment. The results supposed that the removal mechanism of the electrical treatment involved peeling off the resin by gas generated by water electrolysis.

Vol. C pyright 52 No. ©52019 2019The Society of Chemical Engineers, Japan The development of a base metal catalyst which shows high performance for the ammonia (NH3) decomposition have been conducted. For the Ni and Co based catalysts using α-Al2O3 as a support, the performance of the single metal catalysts was lower than that of the γ-Al2O3 supported catalysts. However, its performance was greatly improved by using a binary metal catalyst system. Based on the XRD analysis, it was found that Ni and Co supported on α-Al2O3 were alloyed. TEM observation confirmed that the metal particle size in the α-Al2O3 supported Ni–Co catalyst is smaller than that of the single metal catalysts (Ni/α-Al2O3 or Co/α-Al2O3). Furthermore, in-situ XRD and H2-TPR measurements revealed that the Ni–Co alloy forms during the reduction process. The optimum mixing ratio of Ni and Co components was 1: 1, and the optimum pre-reduction temperature before the performance test was 600°C. Studies on the differences of support oxides proved that the improvement effect by alloying can be similarly obtained with the SiO2 supported catalyst, indicating that the catalyst using the support with less interaction between the active metal and the support is more likely to obtain the performance improvement effect by alloying.

We investigated the durability of Ni/TiO2 catalyst in CO selective methanation reaction. In the reaction test up to 72 h, trace amounts of chlorine component contained in the catalyst gradually decreased. As a result, the progress of the methanation of CO2 increased, leading to a decrease in the reaction selectivity of the methanation of CO in the title reaction. By contrast, in the early stage of the reaction in which the elimination of chlorine component was small, it was confirmed that the number of active sites of metallic Ni increased, and the CO methanation activity was improved. Furthermore, it was found that the chlorine component in the catalyst was more remarkably removed by exothermic reaction heat under the methanation reaction atmosphere as compared with the case of heat treatment under other atmosphere. Catalyst durability under the conditions simulating a daily start-up and shut-down operation that repeated a cycle of cooling and heating the temperature of the catalyst layer to room temperature was also evaluated. As a result, we revealed that a trace amount of chlorine component was removed by exposure to condensed water, leading to a decrease in the reaction selectivity of the catalyst.

Accelerated deterioration tests for selective CO methanation over Ni/TiO2 catalysts were conducted to study the catalyst degradation factors. The accelerated deterioration test treated the catalyst in the reaction gas flow at the specified temperature (200°C, 250°C, or 300°C) for 24 hr. After the accelerated deterioration test, the Ni/TiO2 selectivity in CO methanation was reduced due to the enhancement of an undesirable reverse water-gas shift reaction. Powder X-ray diffraction revealed unchanged TiO2 structure between the fresh and spent catalysts. In-situ X-ray absorption spectroscopy indicated that the H2-reduced Ni species were present as metallic Ni and remained unchanged in the fresh and spent catalysts. The number of surface Cl species for the spent catalyst was much smaller than that for the fresh catalyst. Thereby, disappearance of surface Cl components during the accelerated deterioration test caused the degradation of Ni/TiO2 catalysts for selective CO methanation.

CO2 methanation over sponge Ni was investigated. When CO2 methanation was carried out using sponge Ni without any pretreatment, the sponge Ni exhibited a CO2 conversion of 83% at 250 degrees C under a high space velocity (0.11 mol(CO2) g(cat)(-1) h(-1)). We think that the sponge Ni is a promising new catalyst for CO2 methanation because it showed the high activity even under the high GHSV, and we can design a small plug flow reactor compared to a conventional reactor, resulting in a low manufacturing cost for the reactor. The high activity can be derived from the great number of crystal defects of fcc-Ni in the sponge Ni. On the other hand, with high-temperature pretreatment, the sponge Ni lost its activity in CO2 methanation as well as the surface defect sites. Thus, the activity loss can be explained by the disappearance of the surface defect sites by the high-temperature pretreatment. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

The effect of adding Ag to CuO-ZrO2 catalysts for the hydrogenation of CO2 to methanol was investigated using CuO-ZrO2, Ag/CuO-ZrO2, and Ag/ZrO2. The addition of Ag to CuO-ZrO2 catalysts decreased the specific surface area and also broke its mesostructure. Thus, Ag played a significant role as a sintering aid in the preparation of Ag/CuO-ZrO2 catalysts. We note that the as-prepared Ag/CuO-ZrO2 catalysts contained Ag+ and Zrq+ (q &lt; 4) sites and that the Zrq+ content increased with increasing Ag+ content. Furthermore, the presence of CuO in the Ag/CuO-ZrO2 catalyst appeared to stabilize Ag+ and Zrq+ species under air. Based on H-2 chemisorption and powder X-ray diffraction patterns, formation of a Ag-Cu alloy was observed on completely reduced and spent Ag/CuO-ZrO2 catalysts. Completely reduced Ag/CuO-ZrO2 catalysts exhibited a higher methanol production rate (7.5 mL h(-1) g(cat)(1)) compared to completely reduced CuO-ZrO2 (6.9 mL h(-1) g(cat)(1)) and Ag/ZrO2 catalysts (2.2 mL h(-1) g(cat)(1)) under the following reaction conditions: CO2/H-2/N-2 = 1/3/1, catalyst loading = 500 mg, W/F-total = 1000 mg(cat) s mL(-1), reaction temperature = 230 degrees C, pressure = 10 bar. (C) 2017 Elsevier Inc. All rights reserved.

Sulfur tolerances of alpha-Al2O3 supported noble metal (Rh, Pt, Ir, and Ru) catalysts for steam methane reforming (SMR) at 700 degrees C were examined. Methane conversions over all catalysts decreased in the presence of dimethyl sulfide (DMS) as a sulfur contaminant in the SMR feed. Higher DMS concentration in the SMR feed accelerated the degradation rate of all catalysts. In general, sulfur poisoning is one of major reasons for catalyst degradation. The catalysts showed different degradation behaviors depending on the DMS concentration and the active metal species. Rh and Ru catalysts were deactivated completely within the first few hours of SMR with DMS. Methane conversions over Pt and Ir catalysts also decreased to some extent within hours, but subsequently remained unchanged. Pt and Ir catalysts poisoned by sulfur were fully regenerated after stopping the DMS feed, and Rh catalyst poisoned by sulfur recovered to some extent, whereas Ru catalyst poisoned by sulfur was little regenerated.

Reversible oxygen sensing abilities based on blue and orange photoluminescence in the solid state are achieved by using newly synthesized copper(I) complexes bearing diimine and dodecafluorinated di-phosphine ligands. We found that the blue emission of [Cu(dmp)(dfppe)]PF6 (dmp = 2,9-dimethyl-1,10-phenanthroline, dfppe = 1,2-bis[bis(pentafluorophenyl) phosphino] ethane) in the solid state is very strong under argon, while it is nearly invisible under air. Single crystal X-ray structural analysis reveals that the complex has significant columnar void spaces. [Cu(dmp)(dfppe)] PF6 shows an extremely long lifetime of the emission in the solid state under an argon atmosphere (tau(1) = 160 mu s (88%), tau(2) = 22 mu s (12%)), which is one of the largest values for all copper(I) complexes bearing diimine ligands, and it is drastically decreased under air (tau(1) = 2.4 mu s (85%), tau(2) = 0.5 mu s (15%)). The employment of the dfppe ligand markedly increases the contribution of ligand centred transition, leading to the long-lived excited state. The orange oxygen responsive emission of [Cu(47dmp)(dfppe)]PF6 (47dmp = 4,7-dimethyl-1,10-phenanthroline) is also examined with the help of an investigation of the photophysics of five new compounds of the copper(I) complexes.

Electrochemical synthesis of ammonia (NH3) using a proton conducting solid electrolyte and nickel (Ni) cermet electrodes has been studied. As an electrolyte, BaCe0.9Y0.1O3-delta (BCY) perovskite-type oxide was prepared by a co-precipitation method and its electrolyte pellet was synthesized by the sintering method with small amount of nickel oxide (NiO) as a sintering aid. The Ni-BCY cermet was employed as electrodes of anode and cathode. To evaluate the performance of this cell, electrochemical synthesis of NH3 from dry nitrogen (N-2) and wet hydrogen (H-2) was conducted at 500 degrees C. As a result, the maximum formation rate of NH3 was 3.36 x 10(-10) mol s(-1) cm(-2) at the applied voltage of -0.2V against open circuit voltage using the Ni-BCY vertical bar BCY(NiO)vertical bar Ni-BCY cell, and the Faradic efficiency was 0.63%. Durability test of NH3 electrochemical synthesis from dry N-2 and wet H-2 revealed that current density of cell was relatively stable for 15 h but NH3 formation rate was decreased slightly. In addition, using Ni-BCY based cell, NH3 was successfully synthesized from dry N-2 and steam diluted argon with the applied voltage of -1.8V at a rate of 2.79 x 10(-10) mols(-1) cm(-2) and the Faradic efficiency was 0.15%. And this fabricated cell kept the high NH3 formation rate during the long-term test at -2.0V for 15 h. (C) 2017 The Ceramic Society of Japan. All rights reserved.

<p>大規模植林は，地球温暖化対策として最も有効な方法である．高吸水材は，半乾燥地及び乾燥地で植林された樹木の生存と生育に効果的とされている．水吸収を目的とした吸水材は化学的合成法で製造されているが，安定で分解され難い特徴がある．</p><p> 著者らは，大規模植林のための生物分解性を備えた高吸水性保水材の合成を目的とした．本研究では反応開始試薬Cerium ammonium nitrate（CAN）と架橋結合試薬N-methylenebisacrylamide（MBA）を用い，Chitosanの分子構造へAcrylic acid monomerを接合した．著者らは，Chitosanを新生物分解性保水材合成の基礎物質として使用した．合成した物質の特性は，赤外分光光度計（FTIR），¹³C核磁気共鳴装置（NMR）， 走査型電子顕微鏡（SEM），示差走査熱量測定（DSC）で検討した．また，合成した物質の保水能は乾湿計（Psychrometer）で評価し，熱安定性については示差走査熱量測定（DSC）で評価した．</p>

The synthesis of zirconia with large specific surface area by the hard template method has been conducted using KIT-6 mesoporous silica. Composite materials of tetragonal zirconia and silica were successfully synthesized by the decomposition of zirconia sources in the mesoporous space of KIT-6, while zirconia in the monoclinic and tetragonal phases was synthesized by the conventional pyrolysis method from the same zirconium sources. The formation behavior of tetragonal zirconia depends on the zirconium source, the pore size of mesoporous silica, the amount of the introduced zirconia source, and the calcination temperature. We conclude that the crystallization of zirconia in the mesoporous space results in the formation of fine zirconia particles (crystallite size effect), leading to the formation of a pure tetragonal zirconia crystal. Furthermore, the nanosized tetragonal zirconia possessing large BET specific surface area was synthesized by removing the silica component in the zirconia-silica composite with alkaline treatment. Additionally, we have evaluated the catalytic performance of tetragonal zirconia materials for methanol oxidative decomposition. Among the zirconia samples synthesized in the present study, the sample prepared by the hard template method and calcined at 800 degrees C exhibited the highest activity for methanol oxidation. We deduce that crystallinity of zirconia and high BET specific surface area are necessary to achieve high catalytic activity.

Ammonia by-production for steam methane reforming over alpha alumina (alpha-Al2O3) supported noble metal catalysts was investigated using the methane containing nitrogen feedstock for residential fuel cell. Ammonia is poisonous substance for carbon monooxide preferential oxidation (CO-PROX) catalyst, Pt elctrode, and proton exchange membrane (PEM) in the polymer electrolyte fuel cell system. The ammonia concentrations in the reformed gases at 700 degrees C under SV = 10,000 h(-1) condition over commertial Ni and Ru catalysts were 20 ppm and 81 ppm, respectively. In the case of the Ru catalyst, ammonia concentration almost reached the chemical equilibrium value at 700 degrees C. Ammonia formation performance over 0.5 wt% metal (Rh, Pt, Ir, and Ru) supported on alpha-Al2O3 catalyst prepared by the impregnation method was compared at 700 degrees C under SV = 2,500 h(-1) condition; the ammonia concentrations in the reformed gases over the Rh, Pt, and Ir catalysts were below 0.1 ppm. The order of ammonia formed amount over the catalysts was as follows: Ru &gt; &gt; Rh, Pt, Ir. The ammonia formation can be substantially suppressed during steam reforming of methane containing nitrogen over the Rh, Pt, and Ir catalysts. (C) 2016 Elsevier B.V. All rights reserved.

アルカリ処理を施したFER型ゼオライトとCu/ZnO/Al₂O₃を混合した二元機能触媒のジメチルエーテル水蒸気改質反応における活性及び耐久性の評価を行った。その結果、適切なアルカリ処理を行うことでゼオライト構造が階層化し、Cu系触媒と混合した際、両触媒の活性サイトがより近接することで高活性かつ高耐久性を有するゼオライト混合Cu系触媒が得られた。

燃料電池システムへの搭載を考えた既存の水素化脱硫法に代わる天然ガスの簡易脱硫法として、水素添加を必要としない触媒を用いた直接分解脱硫法の検討を行っている。本研究では、天然ガスに付臭剤として含まれるジメチルスルフィドを分解対象物として、アルミナ担持ニッケル触媒を硫化処理し、300℃から400℃の温度で水素を添加せずに硫化水素に分解する反応について調べた。

Ni-alpha-Al2O3, Ni-SiO2, Ni-gamma-Al2O3, Ni-TiO2, and Ni-ZrO2 were prepared by physical mixing of metal oxides with sponge Ni, and the effect of physical contact of the metal oxides with sponge Ni on selective CO methanation was examined. The prepared Ni-TiO2 catalyst removed CO more deeply and suppressed CO2 methanation better relative to the other catalysts. The metal oxide nature of the prepared Ni catalysts affected the CO2 methanation activity, as well as the reverse water gas shift activity. Moreover, the catalytic performance for the five catalysts was not related to contact time. These results predicted the appearance of new active sites between sponge Ni and the metal oxides.

To develop a new catalyst for catalytic decomposition of volatile organic compounds (VOCs), the activity of various oxide supported silver (Ag) based catalysts for methanol (MeOH) oxidation reaction have been evaluated. Based on the activity evaluation, zirconia (ZrO2) is considered to be a substitute to ceria (CeO2) as a support material. The ZrO2 supported catalyst loading Ag component can oxidize MeOH to CO2 completely, while the main product is CO for MeOH oxidation over pure ZrO2. In the present work, 2.0 wt.% Ag/ZrO2 exhibits excellent activity comparable to Ag/CeO2. Furthermore, according to in situ FT-IR analysis over Ag/ZrO2 and pure ZrO2, it is considered that the methoxy, formate, and bicarbonate species adsorbed on the ZrO2 surface are intermediate species. We thus deduce that Ag component significantly enhances the oxidation step of methoxy species to CO2 via formate species, leading to the complete oxidation of MeOH to CO2 over Ag/ZrO2 catalyst. (C) 2015 Elsevier B.V. All rights reserved.

Catalytic performance of titania supported nickel catalyst (Ni/TiO2) with pre-treatments for the selective methanation of CO (CO-SMET) in reformate gas has been studied to elucidate the role of chlorine component in the methanation activity and CO/CO2 reaction selectivity in CO-SMET. Raw commercial TiO2, used as the support material, contains a certain amount of chlorine component, and the chlorine component can be removed by the heat treatment in air and water washing treatment. The Ni/TiO2 catalyst prepared from the TiO2 containing chlorine component exhibited high CO/CO2 reaction selectivity, that is, low CO2 methanation activity due to its low reverse water gas shift (r-WGS) activity, while the catalysts containing no chlorine component displayed quite low selectivity. The evaluation of the activity of the Ni/TiO2 catalysts prepared from the starting Ni salts with different mixing molar ratios of Ni chloride and Ni nitrate indicates that a trace amount of chlorine led to the improved CO/CO2 reaction selectivity in CO-SMET. The chlorine component in the Ni/TiO2 catalysts is considered to be located on the interface of the Ni particles and the TiO2 support, giving rise to the suppression of CO2 methanation via the r-WGS step. (C) 2015 Elsevier B.V. All rights reserved.

Catalytic direct decomposition of t-butanethiol (TBT) into hydrogen sulfide over zeolites without hydrogen addition was examined as a new desulfurization process for fuel cell systems. TBT is a widely used odorant in pipeline natural gas, and was easily decomposed into hydrogen sulfide and isobutene over H-Y and H-beta at low temperatures of 25-150 degrees C. However, catalyst deactivation of H-beta was observed at 60 degrees C and oligomerized products of isobutene were observed on the catalyst surface after long reaction times. The deactivation rate of TBT decomposition over H-beta increased with higher acid amounts of H-beta. The amount of oligomerized products deposited on the catalyst increased with lower TBT conversion in the initial stage of reaction. The deposition of oligomerized products and catalyst deactivation decreased after several hours. The amount of the oligomerized products deposited on the catalyst reached approximately 6 wt% after 8 h and remained constant after 125 h over H-beta (Si/Al= 92.5) at 150 degrees C. The initial TBT conversion was constant during 125 h.

Pd-supported tungsten oxide ( Pd/WO3) was prepared by photodeposition by using black light. X-ray diffraction and X-ray photoelectron spectroscopy analyses of Pd/WO3 confirmed the presence of Pd(0). Pd(0) was uniformly dispersed on the surface of WO3. The optimum Pd amount for the degradation of aqueous methylene blue (MB) was 0.5 wt%, and the photocatalytic activity in this case was 27 times higher than that of pure WO3. The optimum Pd amount for the decomposition of gaseous acetaldehyde was 0.1 wt%, and the photocatalytic activity using this amount of Pd was 5.9 times greater than that for pure WO3. Pd as a support improved the charge separation efficiency. Further, hydrogen peroxide was produced on the Pd(0) side of the photocatalyst because of the movement of photoexcited electrons, and it contributed significantly to MB degradation. Moreover, electrons produced with MB moved to the Pd side, and contributed to hydrogen peroxide production. Only photocatalytic degradation contributed to acetaldehyde decomposition, while both photocatalytic and self-sensitized degradation contributed to MB degradation. The Pd/WO3 sample containing the optimal amount of Pd acted as an effective photocatalyst, despite the difference between the optimal Pd amount required for acetaldehyde decomposition and that for MB degradation. (C) 2014 Elsevier B.V. All rights reserved.

As a new desulfurization process for fuel cell systems, catalytic direct decomposition of methanethiol into hydrogen sulfide on various metal oxides without hydrogen addition has been examined. Methanethiol was decomposed into hydrogen sulfide over several metal oxide catalysts at 300 degrees C. Major metal oxide catalysts used in this study decomposed methanethiol completely at 500 degrees C. However they would be sulfurized immediately by the decomposed products. Among them, titania (TiO2) catalyst exhibited a remarkable methanethiol decomposition activity and it was hardly sulfurized. The methanethiol conversion of TiO2 catalyst depended on the specific surface area. Hydrogen sulfide and dimethyl sulfide were produced with the same amount at below 250 degrees C. The methanethiol seems to be decomposed by the following equation at low temperature range: 2CH(3)SH -&gt; H2S + (CH3)(2)S. In contrast, hydrogen sulfide and methane were produced as gas phase products and carbon species were also formed on TiO2 surface above 400 degrees C. The methanethiol seems to be decomposed by the following equation at high temperature range: 2CH(3)SH -&gt; 2H(2)S + CH4 + C. We conclude that the direct decomposition of methanethiol on TiO2 surface proceeds via different reaction pathways depending on the reaction temperatures. (C) 2014 Elsevier B.V. All rights reserved.

発電所で発生する余剰電力を用いて水を電気分解することで得られる水素をCO₂と反応させてメタン化することによりCO₂を再利用できるとともにメタンを水素エネルギーキャリアとして利用することができる。さらにメタン燃料は既存のガスラインを利用できる利点からもエネルギーキャリアとして有用である。そこで本研究では、CO₂メタン化活性の高い触媒とされるNi/CeO₂触媒に替わる新規触媒としてスポンジNi触媒に着目し、その触媒特性の評価を行った。

様々な用途で需要のあるアンモニアは水素キャリアとしても注目されている。余剰電力を利用し、窒素と水からアンモニアを合成する電解合成法は、ハーバー・ボッシュ法に代わる合成法として近年期待されている。本研究では、プロトン伝導体であるBaZr_0.9Y_0.1O_3-&delta;(BZY)にRuを担持し、触媒的アンモニア合成反応特性を評価した。特に反応次数やBZYの最適組成比の検討を行い、より高性能な電極触媒の開発を行った。