Dispersion improvement and activity promotion of Pt catalysts supported on a Ce-based support by pH adjustment

Abstract

Developing advanced catalysts that deliver high metal dispersion and outstanding catalytic activity is crucial for practical demand. In incipient wetness impregnation, the metal precursor–support surface interactions are very weak, which usually results in severe sintering and poor dispersion of the active component. In this work, Pt catalysts supported on a CZLP support are prepared via an impregnation method with pH adjustment of the precursor solutions. This means can enhance the Pt precursor–support interactions, and as a result, the Pt species are highly dispersed on the surface of the support. Meanwhile, the catalysts prepared by pH adjustment possess preferable reducibility, excellent thermostability and a smaller Pt nanoparticle size. Thus, the modified catalysts exert a positive effect on converting all target poisons, regardless of fresh or aged samples. When the pH of the impregnating solution is about 3, the catalyst exhibits the optimal performance. Therefore, this work provides a simple and valid synthesis route for advanced catalysts to purify vehicle exhaust.