Silanol nest engineering in ga-silicalite zeolites for controlled ZnO dispersion and enhanced catalytic performance

Controlled defect construction in zeolites provides an effective approach to modulating metal dispersion and stability. In this work, a series of Zn-loaded Ga-silicalite (GS-1) catalysts were prepared via nitric acid leaching to investigate how Ga extraction–induced silanol nests influence Zn dispersion and catalytic behavior in propane dehydrogenation (PDH). The selective removal of Ga generated increased populations of silanol nests while largely preserving the MFI framework, which was accompanied by improved dispersion and structural stabilization of Zn species, likely through Zn–O–Si interactions. Catalytic evaluation at 550 °C and 0.1 MPa revealed that the acid-treated catalysts exhibited suppressed deactivation behavior under PDH conditions. Among the catalysts studied, 5%Zn/0.6GS-1–12 N catalyst achieved the most balanced performance, with a deactivation constant reduced from 0.0546 to 0.0201 h − 1 . These results highlight the role of Ga extraction–induced defects in regulating metal–support interactions and mitigating catalyst deactivation in PDH.