名古屋大学 · 材料科学
Mizuki Tada教授の研究室は、酸化物表面に担持された金属錯体を用いた新規触媒の設計とその反応機構解明を柱としています。特に、燃料電池の白金カソードにおける動的表面反応や、不斉酸化的カップリング反応のための高選択性触媒開発が顕著です。XAFSを用いた非破壊な4次元イメージング技術の開発により、触媒の化学状態と三次元分布を同時に可視化する画期的な手法を確立しています。
Figures are computed from collected data and may differ slightly.
On the Pt/C cathode in a fuel cell, dynamic surface events were investigated by novel X-ray absorption techniques (see Fourier transform for the oxidation process, 0.4→1.0 V). Evidence for Pt dissolution at the cathode was found, and the reaction kinetics of the electron-transfer processes, as well as redox structural changes and a significant time lag between the events, were observed for the first time under operando conditions. Supporting information for this article is available on the WWW u
This review covers several recent topics of novel catalyst design with supported metal complexes on oxide surfaces for selective catalysis such as chiral self-dimerization to create asymmetric oxidative coupling catalysis, surface functionalization with achiral reagents to promote asymmetric catalysis, and molecular imprinting to design shape-selective catalysis. The new concepts and designs find wide applications to a variety of selective catalysts.
Four-dimensional visualization of Pt/C cathode catalyst layers in membrane electrode assemblies (MEAs) were successfully performed by a newly developed method, namely laminography–XAFS (X-ray absorption fine structure). The method not only enables imaging of the 3D distribution of Pt nanoparticle cathode catalysts, but also the chemical states of the Pt catalysts in fresh and degraded MEAs in a nondestructive manner.
The self-dimerized chiral assembly of vanadium-Schiff-base complexes was found to occur on a SiO2 surface and to be the first heterogeneous catalyst for the asymmetric oxidative coupling of 2-naphthol with 100% selectivity and 90% enantioselectivity.
We have prepared a novel Ru-mononer complex supported on a SiO(2) surface by using a Ru-monomer complex precursor with a p-cymene ligand, which was found to be highly active for the selective oxidation of aldehydes and the epoxidation of alkenes using O(2). The structure of the supported Ru catalyst was characterized by means of FT-IR, solid-state NMR, diffuse-reflectance UV/vis, XPS, Ru K-edge EXAFS, and DFT calculations, which demonstrated the formation of isolatedly located, unsaturated Ru ce
A new molecular-imprinted Rh−amine complex with a template-shaped cavity acting as a shape-selective reaction space was prepared by metal-complex attaching and molecular imprinting techniques on a SiO2 surface. Rh(η3-C3H5)3 reacted with SiO2, and the precursor was attached on the surface to form a bidentate structure Rh(C3H5)(OSi)2. α-Methylbenzylamine with a shape similar to that of a half-hydrogenated alkyl intermediate of α-methylstyrene coordinated to the attached Rh as a template ligand. Th
Abstract Oxygen storage and release with oxygen diffusion in the bulk of the cerium–zirconium solid solution oxide Ce 2 Zr 2 O x ( x = 7–8), which possesses an atomically ordered arrangement of cerium and zirconium atoms, is the key to three-way exhaust catalysis. Oxygen storage proceeds via heterogeneous oxygen diffusion into the vacant sites of Ce 2 Zr 2 O 7 particles, but the heterogeneous oxygen diffusion track is erased after oxygen storage in the Ce 2 Zr 2 O x bulk. Here we show three-dime
This paper reports the catalytically active structure, its structural transformation and dynamics, and the reaction mechanism for direct phenol synthesis from benzene and molecular oxygen on a novel N-interstitial Re10-cluster/HZSM-5 catalyst, which exhibited remarkable phenol selectivities of 91.6−93.9% at 1.7−9.9% conversions in pulse reactions and 82.4−87.7% at 0.8−5.8% conversions in steady-state reactions. The active N-interstitial Re10 cluster for the direct phenol synthesis with O2 as an
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