Development of a catalytic reaction process for low-temperature synthesis of valuable chemicals from difficult-reactivity lower alkanes.

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K18845
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 27:Chemical engineering and related fields
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Tago Teruoki 東京工業大学, 物質理工学院, 教授 (20304743)
• Project Period (FY): 2021-07-09 – 2023-03-31
• Keywords: ゼオライト内包貴金属触媒 / ゼオライト / 貴金属 / 内包構造 / 脱水素反応 / クラッキング反応 / 低級オレフィン / ナフサ低温接触分解

Outline of Final Research Achievements

Propylene and other lower olefins are important raw materials for chemical products. In industrial processes, naphtha is thermally decomposed under steam at temperatures of 800 °C or higher, but this method is energy-intensive. In this study, we developed a zeolite-encapsulated catalyst consisting of noble metal particles, enabling low-temperature catalytic cracking of naphtha. This catalyst allows simultaneous dehydrogenation on the noble metal and cracking reactions on the acid sites within the same catalyst. We used n-hexane and n-pentane as model reactants to investigate the effects of supported metal species, metal loading, solid acid amount, and reaction conditions on product yield. Dehydrogenation on the metal was identified as the rate-limiting step in this reaction. Remarkably, we achieved yields of lower olefins exceeding 20 C-mol% under low-temperature conditions of 450 °C.

Free Research Field

化学工学

Academic Significance and Societal Importance of the Research Achievements

貴金属ナノ粒子をゼオライト粒子内に固定化させた内包構造触媒の開発，および同触媒の調製法を開発した．ここでは，ゼオライトの酸量，および金属の担持量に依存せず，３～４nm程度の単分散金属ナノ粒子をゼオライト内へ固定化することに成功している．同触媒は，貴金属とゼオライトに由来する触媒活性を有している．そのため， C5～C6ナフサ成分の分解反応に対し，貴金属上でのアルカン脱水素反応によるアルケン生成，および酸点上での生成アルケンのクラッキングによるC2～C4オレフィン（低級アルケン）合成を，同一触媒内で逐次的に進行させることが可能となり，さらに反応温度を450℃程度まで低温化させることに成功した．