Construction of prediction method for acid strength based on orbital interactions toward zeolitic catalyst design

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K17720
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Functional solid state chemistry; Catalyst/Resource chemical process
• Research Institution: The Institute of Statistical Mathematics (2019); Tokyo Institute of Technology (2017-2018)
• Principal Investigator: Hayashi Yoshihiro 統計数理研究所, ものづくりデータ科学研究センター, 特任助教 (80739029)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 量子化学計算 / ゼオライト / 軌道相互作用

Outline of Final Research Achievements

The aim of this study is to develop a method for predicting the acidity of zeolite catalysts. This study investigated influence of the acid site structure in zeolites (Si-(OH)-Al group) on the deprotonation energy (DPE), which is one of the index of the acid strength. The results show that the lone pair orbitals on the oxygen of the Si-(OH)-Al group interact the anti-bonded orbitals on adjacent Si-O and Al-O bonds (n-σ* interactions). The n-σ* interactions contribute to the reduction of DPE. In addition, the relationship between the local structure of Si-(OH)-Al groups in various zeolite frameworks and DPE was found, and the relationship can be explained by the orbital overlap of the n-σ* interactions.

Free Research Field

計算化学

Academic Significance and Societal Importance of the Research Achievements

ゼオライトの構造と酸強度との間の相関を、軌道相互作用に基づき理論的に説明した。これにより、従来は複雑な構造パラメータを用いて記述されていた構造と酸強度の関係性を、軌道の重なりを用いて単純かつ直観的な取り扱いを可能とした。この成果は、ゼオライト系触媒のスクリーニングや、近年着目されている機械学習を用いた触媒開発手法である、触媒インフォマティクスの分野にも適用できると考えられる。