화학공학소재연구정보센터
Catalysis Today, Vol.259, 165-176, 2016
Development of an active, selective and durable water-gas shift catalyst for use in membrane reactors
Rh(0.6%)/La2O3 and Rh(0.6%)/La2O3(27 wt%) SiO2 were assayed for the WGS reaction at 673K and 1 atm. They were both more active than industrial Cr-Fe based catalysts. Rh(0.6%)/La2O3 was the most active but it progressively deactivated. To investigate its deactivation and the stability of the Rh(0.6%)/La2O3(27 wt%) SiO2, the WGS reaction was carried out in a DRIFTS cell in operando mode. The deactivation of the former was due to the strong adsorption of intermediate oxygenates. Another disadvantage of the Rh formulations was their methanation activity. Therefore, a series of formulations containing 0.1 wt% through 1.2 wt% Pt supported on La2O3(27 wt%) SiO2 were synthesized and catalytically evaluated in a fixed-bed reactor. The activity, methane formation and stability were carefully checked. 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 negligible methanation occurred. It maintained the activity and selectivity after 155 h on stream. This catalyst was tested in a Pd-Ag membrane reactor to produce ultrapure H-2 (<10 ppm of CO) that can be used to feed a low temperature PEM fuel cell. Comparing our results with those already published, it is concluded that our system is one of the best ones reported so far. (C) 2015 Elsevier B.V. All rights reserved.