Effect of chloride on the sinterization of Au/CeO2 catalysts

• Type: Article in International Scientific Journal
• Date: 2010

Authors

S. A. C. Carabineiro (Author) FEUP; A. M. T. Silva (Author) FEUP; G. Dra¸ić (Author) Other; P. B. Tavares (Author) Other; J. L. Figueiredo (Author) FEUP

Journal

Title: Catalysis Today

Vol. 154

Pages: 293-302

ISSN: 0920-5861

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 36 Citations

ISI Web of Science

Scopus - 47 Citations

COMPENDEX

Scientific classification

FOS: Engineering and technology > Other engineering and technologies

CORDIS: Physical sciences > Chemistry > Heterogeneous catalysis

Other information

Authenticus ID: P-003-2V1

DOI: 10.1016/j.cattod.2009.12.017

Abstract (EN): Gold was loaded on commercial CeO2 and on ceria prepared by the solvothermal method (at pK(a) = 8.5 at T = 120, 150 and 220 degrees C, and pK(a) = 26.5 at T = 150 degrees C) by a traditional impregnation method (IMP) and by liquid-phase reductive deposition (LPRD). Activities for CO oxidation were compared and results discussed. Ceria samples prepared by IMP showed up to 1.1 wt.%. chloride present and much lower activity than those prepared by LPRD, which had no residual chloride. Full CO conversion was obtained at similar to 200 degrees C for most LPRD samples, while at that same temperature, for the IMP samples, the conversion varied from 2% (commercial ceria) to 16% (solvothermal ceria prepared at pK(a) = 8.5 and T = 120 degrees C). Sintering of gold was quite evident in all IMP materials, possibly due to the presence of chloride. The commercial CeO2 was the most sensitive to chloride, only achieving full CO conversion at similar to 700 degrees C, thus behaving similarly to the support. This was likely due to the large Au nanoparticle size (up to 400 nm), when compared with the solvothermal ceria (up to 200 nm). LPRD samples had lower particle sizes (ranging from 3 to 50 nm) and contain gold in the oxidic form, while IMP samples showed gold in the reduced form.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10