Optimizing Metal Sites in Hierarchical USY for Selective Hydrocracking of Naphthalene to BTX

TL;DR

This paper explores how to optimize metal catalysts on a special type of zeolite to efficiently convert naphthalene into valuable aromatic compounds like benzene and xylene.

Contribution

The study introduces a novel catalyst design with optimized metal-acid balance and hierarchical pore structure for selective hydrocracking.

Findings

The Ni1W/HPY catalyst achieved 100% naphthalene conversion with 92.5% BTX yield.

Hierarchical porosity improved mass transport and active site accessibility.

Optimized metal-acid synergy suppressed coke formation and enhanced selectivity.

Abstract

Metal components (CoMo, NiMo, NiW) supported on hierarchical porous USY zeolite (HPY) were systematically optimized for selective naphthalene hydrocracking to BTX (benzene, toluene, xylene). The hierarchical porosity enhanced mass transport and accessibility to active metal sites, improving reaction selectivity and efficiency. Supported metal sulfides served as hydrogenation sites, crucial for aromatic ring activation and coke suppression. By optimizing the synergy between hydrogenation and cracking functions, the optimized Ni1W/HPY catalyst achieved complete naphthalene conversion with a BTX yield of 92.5%. The spatial distribution of WO3 crystallites facilitated functional separation, promoting selective conversion. These findings underscore the importance of metal–acid balance and pore architecture in designing efficient hydrocracking catalysts.

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