Evolution of sulfate during the preparation of Pd/Al2O3 catalyst and its effect on the performance of catalytic hydrogenation

During the manufacture of Al 2 O 3 , sulfate would be inevitably introduced when aluminum sulfate is used as raw material, but its effect has received little attention. In this work, Al 2 O 3 supports with different sulfate content were synthesized and used to prepare Pd/Al 2 O 3 catalyst. Sulfates in all samples exist as surface sulfate, and would be partially removed during the preparation process. Sulfate existing in Al 2 O 3 supports had little impact on the electric structure of Pd, but would partially block pores and also consume surface hydroxyl groups. As a result, higher sulfate content in support would lead to lower Pd dispersion in catalysts and slower reaction rate towards the hydrogenation of amyl-anthraquinone.