The preparation of Pd/CeO2–ZrO2–Al2O3 catalyst with superior structural stability: effect of zirconia incorporation method

Abstract

A series of CeO2–ZrO2–Al2O3 (CZA) supports were prepared by coprecipitation method with different mixed modes of precursors, and the corresponding Pd-only catalysts were acquired with incipient impregnation technique. Interestingly, the CZA3 prepared by mixing of Ce(NO3)3·6H2O–ZrO(CO3)2 mixed solution and ZrO(CO3)2–Al(NO3)3·9H2O mixed solution showed better structural stability; meanwhile, the relevant Pd/CZA3 presented better catalytic activity and the operation window. The characterization results displayed that Zr was introduced into Ce and Al, respectively, could enhance the moderate interaction between Pd and support and increase oxygen vacancies as well as inhibit particle growth, agglomeration and phase separation. Moreover, the Pd–O–Ce bond could be weakened for Pd/CZA3 with appropriate Zr content, which was helpful for enhancing redox activity. Combining the results of characterizations and catalytic performance, it is revealed that the Pd/CZA3 possessed the greatest application potential for (three-way catalysts) TWCs.