Effect of Microwave Drying, Calcination and Aging of Pt/Al2O3 on Platinum Dispersion

Abstract

The effect of heating method employed for drying and calcination during the synthesis of 1 wt% Pt/Al2O3 catalyst was investigated. Conventional heating (CH) in resistive oven and microwave heating (MW) in single mode were applied, and the Pt dispersion and Brunauer-Emmett-Teller (BET) surface area were measured to characterize the samples. It was evidenced that the fast and homogeneous heating offered by the microwave heating led to higher Pt dispersion. However, this benefit was only achieved when the subsequent calcination was performed in a conventional oven. The aging in microwave oven of conventionally prepared—as well as MW-prepared—catalysts demonstrated the great ability of microwave irradiation to accelerate platinum sintering. After 1 h at 800 °C under microwave, catalysts showed a dispersion of 5%. Therefore, microwave treatment should be considered for accelerated catalyst aging but should be avoided as a calcination technique for the synthesis of highly dispersed Pt/Al2O3.

Editorial: Special Issue Catalysis by Precious Metals, Past and Future

“…The Pd catalyst in this case was taken over by Pt and Rh catalysts due to their higher stability upon sintering and their ability to maintain the active site unaltered during the treatment prior reaction and therefore. X. Auvray and A. Thuault [7] chose the Pt/Al 2 O 3 catalyst to study the effect of microwave pretreatment over precious metal dispersion. The microwave heating was compared to the conventional method of drying and calcination.…”

Characterization of niobium photocatalyst precursor obtained by spray drying

“…This drying method can generate particles presenting different shapes and spatial structure, at wide-size range [2]. Some studies have been using vacuum microwave [8] and spray dryers [9,10] at the drying dispersion step; some authors have reported that spray drying use to obtain catalysts is an interesting method, since it improves particle morphology and is an efficient catalytic activity [9,10].…”