Development of an active, selective and durable water-gas shift catalyst for use in membrane reactors

E.A. LOMBARDO ; C. CORNAGLIA; J. MÚNERA

CATALYSIS TODAY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2015 vol. 259 p. 165 - 176

0920-5861

tRh(0.6%)/La2O3and Rh(0.6%)/La2O3(27 wt%)·SiO2were assayed for the WGS reaction at 673 K and1 atm. They were both more active than industrial Cr-Fe based catalysts. Rh(0.6%)/La2O3was themost active but it progressively deactivated. To investigate its deactivation and the stability of theRh(0.6%)/La2O3(27 wt%)·SiO2, the WGS reaction was carried out in a DRIFTS cell in operando mode. Thedeactivation of the former was due to the strong adsorption of intermediate oxygenates. Another dis-advantage of the Rh formulations was their methanation activity. Therefore, a series of formulationscontaining 0.1 wt% through 1.2 wt% Pt supported on La2O3(27 wt%)·SiO2were synthesized and cat-alytically evaluated in a fixed-bed reactor. The activity, methane formation and stability were carefullychecked. The fresh and used catalysts were characterized through a battery of techniques including XRD,LRS and XPS. The Pt(0.1 wt%) formulation resulted the most active one per gram of platinum and negligi-ble methanation occurred. It maintained the activity and selectivity after 155 h on stream. This catalystwas tested in a Pd-Ag membrane reactor to produce ultrapure H2(<10 ppm of CO) that can be used tofeed a low temperature PEM fuel cell. Comparing our results with those already published, it is concludedthat our system is one of the best ones reported so far.