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Zheng, X.*; 加藤 優*; 上村 洋平*; 松村 大樹; 八木 一三*; 高橋 仁徳*; 野呂 真一郎*; 中村 貴義*
Inorganic Chemistry, 62(3), p.1257 - 1263, 2023/01
被引用回数：1 パーセンタイル：58.61(Chemistry, Inorganic & Nuclear)A glass-crystal composite (g-NCP/PCP), comprising a glassy nonporous coordination polymer (g-NCP) and a crystalline porous coordination polymer (PCP)/metal-organic framework, was synthesized by using a melt-quenched method. Compared to that of the PCP itself, g-NCP/PCP has an enhanced gas adsorption selectivity. The results should stimulate further studies of the chemistry of g-NCP/PCP glass-crystal composites.
林田 健志*; 上村 洋平*; 木村 健太*; 松岡 悟志*; 萩原 雅人; 廣瀬 左京*; 盛岡 仁*; 長谷川 達夫*; 木村 剛*
Physical Review Materials (Internet), 5(12), p.124409_1 - 124409_10, 2021/12
被引用回数：17 パーセンタイル：80.41(Materials Science, Multidisciplinary)The ferroaxial order, which is characterized by a rotational structural distortion in a crystal, has been recently proposed as one of ferroic orders. Though the domain formation is a characteristic feature in ferroic materials, there has been little study done concerning that for the ferroaxial order. Here, we investigate ferroaxial domains that are formed through a ferroaxial transition in two representative ferroaxial materials, NiTiO
and RbFe(MoO
)
. We spatially resolve their domain structures using an optical method based on electric-field- induced optical rotation, that is, electrogyration (EG). In NiTiO, multi-domains are constructed when crystals undergo a ferroaxial transition and the domain size depends on the cooling rate around the transition temperature. Furthermore, the ferroaxial domain structure obtained by the EG measurement is well matched with that by scanning X-ray diffraction (XRD). RbFe(MoO) also exhibits multi-domain states in which domain patterns are different each time a crystal undergoes a ferroaxial transition. In addition, the temperature dependence of the EG signal well obeys that of the order parameter of a first-order phase transition. These results ensure the effectiveness of the EG effect to elucidate the nature of ferroaxial order.
加藤 優*; 中干場 亮太*; 小倉 和也*; 徳田 翔一*; 保田 諭; 東 晃太朗*; 宇留賀 朋哉*; 上村 洋平*; 八木 一三*
ACS Applied Energy Materials (Internet), 3(7), p.6768 - 6774, 2020/07
被引用回数：15 パーセンタイル：62.59(Chemistry, Physical)Ptベースのナノ構造触媒の触媒活性に対する窒素ドープおよびポリマーコーティングされたカーボン担体の電子効果を理解するために、酸素還元反応(ORR)にポリベンゾイミダゾール(PBI)コーティングおよびコーティングされていないカーボンナノチューブ上に担持されたPtNiナノフレーム(NF)を調製した。それらの触媒活性および電子特性を、窒素ドープおよびドープされていないカーボン担体に固定化されたNFの触媒活性および電子特性を評価し比較検証した。PBIコーティングと窒素ドーピングは、共にNFの触媒活性を向上させることが分かったが、
X線光電子分光法と
X線吸収分光法により、窒素ドーピングがNFに電子効果を示すのに対し、PBIコーティングはNFの電子状態にほとんど影響を与えないが、電気化学的条件下でPt(OH)
種を安定化することが分かった。我々の研究は、触媒/担体界面における窒素原子の微視的環境の違いが、Ptベースの電極触媒に対する担体の電子効果に敏感であることを示したものである。
加藤 優*; 武藤 毬佳*; 松原 直啓*; 上村 洋平*; 脇坂 祐輝*; 米内 翼*; 松村 大樹; 石原 知子*; 徳島 高*; 野呂 真一郎*; et al.
ACS Applied Energy Materials (Internet), 1(5), p.2358 - 2364, 2018/05
被引用回数：12 パーセンタイル：43.4(Chemistry, Physical)Multinuclear metal active sites are widely used as catalytic reaction centers in metalloenzymes and generally show high catalytic activity. The oxygen reduction reaction (ORR) is an important reaction not only in oxygenic respiration but also in future energy generation devices such as polymer electrolyte fuel cells and metal-air batteries. Incorporation of multinuclear metal active sites in conductive materials such as carbon will allow us to develop highly active electrocatalysts like metalloenzymes. Herein, we report a copper-based ORR electrocatalyst with multinuclear copper active sites in nitrogen-doped graphene. Electrochemical measurements revealed that the obtained electrocatalyst showed the highest electrocatalytic activity for the ORR in the Cu-based electrocatalysts in neutral aqueous solution. In situ X-ray absorption spectroscopy revealed the incorporation of multinuclear copper sites.
本倉 健*; 福田 拓磨*; 上村 洋平*; 松村 大樹; 池田 まりか*; 南保 雅之*; Chun, W.-J.*
Catalysts, 8(3), p.106_1 - 106_8, 2018/03
被引用回数：4 パーセンタイル：10.01(Chemistry, Physical)In this study, mesoporous and nonporous silica-supported Pd complexes were synthesized and characterized. Variable-temperature XAFS measurements and a curve-fitting analysis showed a slightly larger contribution of 
when the Pd complexes were on a nonporous support in comparison to a mesoporous support. In contrast, the catalytic performance of the attached Pd complex in the Suzuki-Miyaura cross-coupling reaction was not affected by such small differences in the static disorder of the Pd complex.
