Acidic property of YNU-5 zeolite influenced by its unique micropore system

Naonobu Katada (1) , Kana Yamamoto (1) , Moeri Fukui (1) , Kai Asanuma , Satoshi Inagaki (2) , Kazuki Nakajima (1) , Satoshi Suganuma (1) , Etsushi Tsuji (1) , Ana Palcic (3) , Valentin Valtchev (3) , Petko St. Petkov , Kristina Simeonova (4) , Georgi Vayssilov (4) , Yoshihiro Kubota (2)

1 Tottori University
2 Yokohama National University
3 LCS - Laboratoire catalyse et spectrochimie
4 Софийски университет = Sofia University

The Brønsted acid strength of YNU-5 zeolite (YFI-type framework) was analyzed by means of the ammonia IRMS-TPD (infrared/mass spectroscopy temperature-programmed desorption) method. In addition, the accessibility of Brønsted acid sites was evaluated by IR spectroscopy using pyridine as a probe molecule. Most of the YNU-5 Brønsted acidic OH groups reacted with pyridine vapor at 343 K to form pyridinium cations, indicating that the Brønsted acid sites are highly accessible through the large 12-member ring (12-ring) channel. The number of Brønsted acid sites was close to the aluminum content in the H-form of YNU-5 zeolite. Enthalpy of ammonia desorption from the Brønsted acid site was in the following order as an indicator of acid strength: FAU < MOR (12-ring) < *BEA < MFI < MWW ≈ YFI < MOR (8-ring). These data will serve to develop new catalytic materials based on YNI-5 zeolite.

Mots clés: YNU-5 zeolite; YFI; Brønsted acid strength; ammonia IRMS-TPD; DFT; accessibility

Domaines: Matériaux

Naonobu Katada, Kana Yamamoto, Moeri Fukui, Kai Asanuma, Satoshi Inagaki, et al.. Acidic property of YNU-5 zeolite influenced by its unique micropore system. Microporous and Mesoporous Materials, 2022, 330, pp.111592. ⟨10.1016/j.micromeso.2021.111592⟩. ⟨hal-03603131⟩