화학공학소재연구정보센터
Industrial & Engineering Chemistry Research, Vol.48, No.1, 430-439, 2009
Comparison of Nanosized Gold-Based and Copper-Based Catalysts for the Low-Temperature Water-Gas Shift Reaction
In this paper the catalytic performances for the low-temperature water-gas shift reaction of Au/TiO2 type A (from World Gold Council), Au/CeO2 (developed at UPV-CSIC), CuO/Al2O3 (from BASF), and CuO/ZnO/ Al2O3 (from REB Research & Consulting) have been compared. The catalysts were characterized by different techniques such as Raman spectroscopy, BET surface area measurements, temperature-programmed reduction, and high-resolution transmission electron microscopy, which gave additional information on the redox properties and textural and morphological structure of the investigated samples. The performances of these catalysts were evaluated in a wide range of operating conditions in a micro packed-bed reactor. It was observed that the presence of reaction products in the feed (CO2 and H-2), as well as CO and H2O feed concentrations, have significant effects on the catalytic performances. With a typical reformate feed the Au/CeO2 catalyst reveals the highest CO conversion at the lowest temperature investigated (150 degrees C). However, while in the long tests performed the CuO/ZnO/Al2O3 catalyst showed a good stability for the entire range of temperatures tested (150-300 degrees C), the Au/CeO2 sample clearly showed two distinct behaviors: a progressive deactivation at lower temperatures and a good stability at higher ones. The selection of the best catalytic system is therefore clearly dependent upon the range of temperatures used.