%0 Journal Article
%T Novel Catalytic Systems for Hydrogen Production via the Water-Gas Shift Reaction
%A Klito C. Petallidou
%A Kyriaki Polychronopoulou
%A Angelos M. Efstathiou
%J Conference Papers in Science
%D 2013
%R 10.1155/2013/426980
%X The present work reports on the development of new catalysts for the production of hydrogen via the water-gas shift (WGS) reaction. In particular, the effect of Ce/La atom ratio on the catalytic performance of 0.5ˋwt% Pt supported on ( ) mixed metal oxides for the WGS reaction was investigated. It was found that the addition of 20ˋat.% La3+ in CeO2 lattice increased significantly the catalytic activity and stability of 0.5ˋwt% solid. More precisely, a lower amount of ※carbon§ was accumulated on the catalyst surface, whereas surface acidity and basicity studies showed that had the highest concentration of labile oxygen and acid sites, and the lowest concentration of basic sites compared to the other mixed metal oxide supports ( ). 1. Introduction The heterogeneously catalyzed water-gas shift reaction is an important part of the reaction network for hydrogen production through steam reforming of hydrocarbons, sugars, alcohols, and biooil [1每5]. The reaction is reversible, moderately exothermic, and equilibrium limited: The WGS reaction can be used to produce H2 and reduce the level of CO in a hydrogen product stream to less than 10ˋppm for fuel cell applications, since CO is deleterious for the fuel cell＊s electrodes [6]. In the last two decades, the interest of the scientific community for low-temperature WGS (LT-WGS) reaction has grown significantly as a result of the advancements made in fuel cell technologies for electricity production [7]. The conventional WGS catalysts which are used in the industry for more than 70 years are Fe3O4/Cr2O3 for operation at the high-temperature range of 350每450∼C, and Cu/ZnO/Al2O3 at the low-temperature range of 180每250∼C. These industrial catalysts require long-time period for activation and are pyrophoric, features that make them inappropriate for fuel cells applications [8]. Thus, it is necessary to develop new catalysts, highly preferable to improve the existing WGS catalytic technology, especially at temperatures lower than 250∼C. Typical characteristics of novel WGS catalysts should include high stability and activity, no need for activation prior to use, and no pyrophoricity. In recent years, supported Pt catalysts (0.1每0.5ˋwt% Pt) using CeO2 and CeO2-based supports have been widely studied [9每16]. Jeong et al. [12] have found that Pt/Ce0.8Zr0.2O2 exhibits higher CO conversions than Pt/Ce0.2Zr0.8O2 due to the higher Pt dispersion achieved, easier reducibility of support, lower activation energy, and higher oxygen storage capacity (OSC), properties which were induced by the cubic structure and composition of
%U http://www.hindawi.com/journals/cpis/2013/426980/