Sulfuric acid decomposition on Pt/SiC-coated-alumina catalysts for SI cycle hydrogen production

Abstract

Sulfuric acid decomposition was conducted at atmospheric pressure and a GHSV of 72,000 mL/g(cat) h in the temperature ranges from 650 to 850 degrees C. The Pt-Al (1wt% Pt/Al2O3) and and Pt-SiC-Al (1wt% Pt/SiC-coated-Al2O3) catalysts were prepared by an impregnation method. The Pt-Al catalyst rapidly deactivated at 650 and 700 degrees C, but was stable at 750 and 850 degrees C. The aluminum sulfate was observed on the spent Pt-Al catalyst by an FT-IR, an X-ray spectroscopy and a TGA/DSC analyzer, which was suggested to be a cause of the deactivation at lower reaction temperature. The alumina support was coated with SiC by a CVD method with methyltrichlorosilane (MTS) to get a non-corrosive support (SiC-Al) with high surface areas. The thermal analysis of the spent Pt-SiC-Al showed that the aluminum sulfate formation was suppressed during the sulfuric acid decomposition. The Pt-SiC-Al catalyst was not only active higher than the Pt-Al catalyst, but was also stable at all the tested reaction temperature. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.