A new X-ray absorption experimental set-up dedicated to DeNO(x) catalysis

In this paper, we present a complete in situ X-ray absorption reaction cell that simulates DeNO(x) experimental conditions. In this device, the sample is placed at high temperature under the flow of a complex mixture of react ive gases (NO, C3H6, O-2, N-2) Particular attention has been paid to the ma terial and design of the sample holders in order to avoid preferential gas circulation and thus ensure a true diffusion of the reactive gases on the c atalyst. Moreover, precise control of the gas flow is maintained by means o f mass flow controllers, and the safety of the set-up is assured by CO, CO2 and NO detectors directly relayed to an electronic device, which is itself linked to the various mass flow controllers. Finally, the possibilities of this device are illustrated through the in situ XANES study of a Cu-ZSM-5 catalytic system. (C) 1999 Elsevier Science B.V. All rights reserved.