Zeolite Y is one of the most important solid acids in the field of heterogeneous catalysis in the past

present and even for a long time in the future. The ultra-stable Y zeolites are the most important form for practical applications. The present review briefly summarized the structure changes of Y zeolite framework under steaming environment

including the removal of framework aluminum

the repair of framework vacancies by migrating silicon insertion

the generation of extra-framework aluminum and the formation of mesopores in the volume of zeolite grains. The emphasis of the present review was on the recent experimental and theoretical progresses about steaming dealumination. The necessity to continue conducting in-depth study on the post-synthesis modification of zeolite Y was stressed.