Development of structure-controlled early transition metal binary oxide based acid-base catalysts and the activity controlling factor

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K05150
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 27030:Catalyst and resource chemical process-related
• Research Institution: The University of Tokushima
• Principal Investigator: YAMAMOTO Takashi 徳島大学, 大学院社会産業理工学研究部(理工学域), 准教授 (70361756)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 酸化ジルコニウム / 第四周期元素 / 複合酸化物 / 酸塩基 / アルキル化 / エタノール転換反応

Outline of Final Research Achievements

Various kinds of Y, Sc and In metal-ion doped zirconia supported tungsten oxides were prepared. As for the catalytic performance for Friedel-Crafts alkylation, optimal ranges of the doping amounts of Sc and In were wider than those for Y.
Group 2, 3, and 13 element-doped zirconium oxide catalysts were prepared by impregnation of each metal salt aqueous solution on amorphous zirconium hydroxide, followed by calcination. ZrO2 doped with other period-4 elements, including all 3d transition metals, were also prepared. As for Ga, doped ions mainly existed inside the bulk of zirconia by forming solid solution up to 5 mol%. Empirical approach for catalysis of Ga2O3-ZrO2 solid solution revealed that acetaldehyde formed by ethanol dehydrogenation was converted to acetone, mainly via acetate species. Coexistence of ZrO2, doped elements with dehydrogenation capability, surface acid-base property, and H2O vapor was important for ethanol to acetone / isobutene reaction.

Free Research Field

触媒化学

Academic Significance and Societal Importance of the Research Achievements

一般に二元系酸化物固溶体は均質な前駆体を焼成することで調製されることが多いが，本研究では金属塩を非晶質水酸化ジルコニウムに含浸担持―焼成する簡単な操作でも固溶体が形成することがあること，簡便な実験的手法で固溶体組成を求められる事が明らかとなった．カーボンニュートラルの観点でバイオマス資源を原料とした化成品原料合成技術の開発が求められており，近年注目されていたジルコニア系複合酸化物触媒によるエタノール転換反応における反応機構，添加金属種，および基質とともに供給される水分子の役割が明らかになった．