Ge-Substituted Hierarchical Ferrierite for n-Pentane Cracking to Light Olefins: Mechanistic Investigations via In-situ DRIFTS Studies and DFT Calculations

The development of heterogeneous catalysts for light olefin production via a catalytic cracking has been crucially important due to the high demand of related products in industrial applications. Herein, we report the structural analysis of a germanium-substituted hierarchical ferrierite zeolite obtained by one-pot synthesis. This is the first report on an investigation of the synergistic effect of hierarchical structures and the one-pot Ge-substitution in a ferrierite framework on the catalytic cracking mechanism. Our findings exhibit that the existence of germanium in a hierarchical ferrierite framework can indeed reduce the Bronsted acid strength, facilitating a catalytic reaction with high light olefin selectivity (63 %) due to the elimination of side reactions, such as dimerization and aromatization, confirmed by in-situ DRIFTS and DFT studies. This opens up the perspective of the development of metal substitution in an interconnected 8- and 10-pore framework with hierarchical structures on the catalytic behaviors of light olefin production.