Work

Nitrogen incorporation in SAPO-34: How urea etching improves catalyst lifetime and selectivity

Year: 2025

Type: article

Abstract: Urea etching of SAPO-34 offers an effective route to enhance its catalytic performance in the methanol-to-olefins (MTO) process. This work examines the effects of nitrogen doping and mesoporosity enhancement on SAPO-34's physicochemical and catalytic properties through combined experimental and theoretical methods, including XRD, FTIR, HR-XPS, NH 3 -TPD, molecular dynamics (MD) simulations, and performance testing. HR-XPS confirms successful nitrogen incorporation, showing increased C N and N C species with reduced C Si and N Si bonds. XRD and FE-SEM reveal decreased crystallinity and particle size, contributing to higher surface area and mesoporosity. NH 3 -TPD indicates moderated strong acid sites and increased weak acid sites, optimizing the acidity profile for improved ethylene selectivity and coke resistance. MD simulations show that nitrogen doping stabilizes methanol conversion steps and suppresses coke precursor formation, prolonging catalyst life. Catalytic tests demonstrate that urea-etched SAPO-34 (SP-UN) surpasses conventional SAPO-34 (SP), achieving higher ethylene selectivity (57.42 %), sustaining high selectivity for over 420 min, and exhibiting slower deactivation. The synergy of framework stabilization, balanced acidity, and enhanced diffusion properties significantly boosts SAPO-34's efficiency and durability in MTO applications.

Source: Fuel Processing Technology

DOI: 10.1016/j.fuproc.2025.108318

Authors: Hossein Mozafari Khalafbadam, Jafar Towfighi Darian, Masoud Safari Yazd

Institution: Tarbiat Modares University

Language: English

Topic: Zeolite Catalysis and Synthesis

Subfield: Inorganic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,180

Funder: Iran National Science Foundation