Publications by authors named "Tomohiro Yabe"

Polyoxometalates (POMs), representing anionic metal-oxo clusters, display diverse properties depending on their structures, constituent elements, and countercations. These characteristics position them as promising catalysts or catalyst precursors for electrochemical carbon dioxide reduction reaction (CORR). This study synthesized various salts-TBA (tetra--butylammonium), Cs, Sr, and Ba-of a dipalladium-incorporated POM (Pd2, [γ-HSiWOPd(OAc)]) immobilized on a carbon support (Pd2/C).

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C-S bond metathesis of thioethers has gained attention as a new approach to the late-stage diversification of already existing useful thioethers with molecular frameworks intact. However, direct or indirect thioether metathesis is scarcely reported, and heterogeneously catalyzed systems have not been explored. Here, we develop heterogeneously catalyzed direct thioether metathesis using a supported Au-Pd alloy nanoparticle catalyst with a high Au/Pd ratio.

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Although supported anionic gold nanoparticle catalysts have been theoretically investigated for their efficacy in activating O in aerobic oxidation reactions, limited studies have been reported due to the difficulty of designing these catalysts. Herein, we developed a feasible method for preparing supported anionic gold nanoparticle catalysts using multivacant lacunary polyoxometalates with high negative charges. We confirmed the strong and robust electronic interaction between gold nanoparticles and multivacant lacunary polyoxometalates, and the electronic states of the supported gold nanoparticle catalysts can be sequentially modulated.

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We focused on identifying a catalytic active site structure at the atomic level and elucidating the mechanism at the elementary reaction level of liquid-phase organic reactions with a heterogeneous catalyst. In this study, we experimentally and computationally investigated efficient C-H bond activation for the selective aerobic α,β-dehydrogenation of saturated ketones by using a Pd-Au bimetallic nanoparticle catalyst supported on CeO (Pd/Au/CeO) as a case study. Detailed characterization of the catalyst with various observation methods revealed that bimetallic nanoparticles formed on the CeO support with an average size of about 2.

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This study rationally designed a heterogeneously catalyzed system (i.e., using Ni-Pd alloy nanoparticles supported on hydroxyapatite (Ni-Pd/HAP) under an H atmosphere) achieving an efficient base-free formal C-S bond metathesis of various thiols via suppression of the Ni catalysis deactivation.

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CePO4 nanorods with uniform surface Ce sites could work as a durable catalyst and showed the highest C2 yield of 18% in an electric field without the need for external heating, which was comparable to that reported for high-performance catalysts at high temperature (>900 K).

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We examined oxidative coupling of methane (OCM) over various Ce-W-O catalysts at 423 K in an electric field. Ce2(WO4)3/CeO2 catalyst showed high OCM activity. In a periodic operation test over Ce2(WO4)3/CeO2 catalyst, C2 selectivity exceeded 60% during three redox cycles.

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