SOFC system with integrated catalytic fuel processing

In recent years, there has been much interest in the development of solid o xide fuel cell technology operating directly on hydrocarbon fuels. The deve lopment of a catalytic fuel processing system, which is integrated with the solid oxide fuel cell (SOFC) power source is outlined here. The catalytic device utilises a novel three-way catalytic system consisting of an in situ pre-reformer catalyst, the fuel cell anode catalyst and a platinum-based c ombustion catalyst. The three individual catalytic stages have been tested in a model catalytic microreactor. Both temperature-programmed and isotherm al reaction techniques have been applied. Results from these experiments we re used to design the demonstration SOFC unit. The apparatus used for catal ytic characterisation can also perform in situ electrochemical measurements as described in previous papers [C.M. Finnerty, R.H. Cunningham, K. Kendal l, R.M. Ormerod, Chem. Commun. (1998) 915-916; C.M. Finnerty, N.J. Coe, R.H . Cunningham, R.M. Ormerod, Catal. Today 46 (1998) 137-145]. This enabled t he performance of the SOFC to be determined at a range of temperatures and reaction conditions, with current output of 290 mA cm(-2) at 0.5 V, being r ecorded. Methane and butane have been evaluated as fuels. Thus, optimisatio n of the in situ partial oxidation pre-reforming catalyst was essential, wi th catalysts producing high H-2/CO ratios at reaction temperatures between 873 K and 1173 K being chosen. These included Ru and Ni/Mo-based catalysts. Hydrocarbon fuels were directly injected into the catalytic SOFC system. M icroreactor measurements revealed the reaction mechanisms as the fuel was t ransported through the three-catalyst device. The demonstration system show ed that the fuel processing could be successfully integrated with the SOFC stack. (C) 2000 Elsevier Science S.A. All rights reserved.