Shinya Kokuryo 교수

This study evaluates the effect of loading various mono and divalent metals in Beta zeolite on low-density polyethylene (LDPE) cracking. We revealed that Tl and Ba ions enhanced Lewis acidity, leading to higher catalytic activity on LDPE cracking.

Nowadays, the increase in plastic waste is causing serious environmental problems. Catalytic cracking has been considered a promising candidate to solve these problems. Catalytic cracking has emerged as an attractive process that can produce valuable products from plastic wastes. Solid acid catalysts such as zeolites decompose the plastic waste at a lower temperature. The lower decomposition temperature may be desirable for practical use. Herein, we synthesized both Zr- and Al-incorporated Beta

The utilization of zeolites in the catalytic cracking of plastics has garnered attention as a promising recycling method. Zeolitic micropores are uniform and exhibit shape selectivity, but their sizes are very small compared to those of polymer molecules. Consequently, the reactions occurring on the external surfaces and near the pore mouths of zeolites are crucial for polymer cracking. However, the role of zeolitic surfaces in polymer cracking has not been clarified. In this study, we controlle

This study is one of the few to develop a strategy that inhibits coke deposition by loading Cr on zeolite defects. We revealed that Cr 6+ species, which interacted with hydroxyl groups in the zeolite framework inhibited coke deposition.

Lewis acidic Sn-Beta zeolites can produce light olefins selectively during LDPE catalytic cracking. The produced light olefins were protected from being converted to other hydrocarbons by the absence of Brønsted acid sites.

Zr-doped SAPO-34 has enhanced Lewis acidity, leading to high catalytic activity for LDPE cracking.

Abstract Zeolite deactivation induced by coke deposition is a critical problem in the industrialization of the chemical recycling (CR) of plastics. We previously demonstrated that Cr 6+ species bonded to silanol groups in the zeolite framework inhibit coke deposition in low‐density polyethylene (LDPE) cracking. In this study, the role of Cr 6+ species and the mechanism of coke reduction were determined experimentally. During LDPE cracking, hydrogen was generated from the alkane products at the C

Abstract Catalysts for the selective recovery of light olefins from polyolefins should be developed to save limited fossil resources. It is previously revealed that Brønsted acid‐free Sn‐Beta zeolites selectively produced light olefins from polyolefin cracking. Brønsted acid sites ionize olefins by protonation and the generated carbenium ions are converted into other hydrocarbons via various reactions, thereby the elimination of their effects led to the improvement of light olefin production abi

Abstract In the long history of zeolite research, further enhancement of their acid strength has looked difficult. In this study, we achieved the enhancement by incorporating Ge into the zeolite framework. We synthesised the zeolites by a dry gel conversion method and characterised them in terms of morphology, crystal structure, and composition. We determined the acid strength of these zeolites by calculating the change in the enthalpy of desorption in the temperature‐programmed desorption of am

Reusable Catalysts In article number 2400625, Shinya Kokuryo, Koji Miyake, and co-workers show that Cr6+ loaded Lewis acidic Sn-Beta zeolites are hardly deactivated and produce light olefins selectively and repeatedly from LDPE cracking without oxidative regeneration.

Oxygen Reduction Reaction In article 2300165, Shinya Kokuryo, Koji Miyake and co-workers shows the utilization of deposited coke on zeolites during the catalytic cracking of nitrogen-containing polymer for the oxygen reduction reaction (ORR). N-doped carbon is obtained by removing the zeolite framework from zeolite/coke composites. The experiments reveal that Zn2+ in zeolites increases the porosity and the number of active Valley-N sites of catalysts resulted in high ORR activity.

The Front Cover shows the effect of Cr6+ species on zeolites for coking resistance during the catalytic cracking of low-density polyethylene. The Cr6+ species can be stabilized by the silanol groups in zeolites and exhibit the dehydrogenation activity of light alkanes, which are produced a lot during the catalytic cracking of polyolefin. Moreover, aromatics, which is a coke precursor can be decomposed via hydrogenation at the zeolitic acid sites. In their Research Article, S. Kokuryo, K. Miyake

Abstract This work focuses on the development of a new method to utilize deposited coke on zeolite catalysts, formed during the plastic waste cracking. Nitrogen‐doped carbon catalysts are prepared using nylon‐66 and Zn 2+ ion‐exchanged ZSM‐5 zeolites. After the cracking reaction, nitrogen‐doped carbon materials are obtained by removing zeolites from zeolite/coke composites using base and acid treatment. The synthesized N‐doped carbon using Zn 2+ type ZSM‐5 zeolites exhibits higher catalytic perf