CATALYTIC ACTIVITY AND STABILITY OF CERIA-SUPPORTED NOBLE METALS (Pt, Rh) CATALYSTS IN THE STEAM REFORMING OF SIMULATED MARINE DIESEL

Diesel is the most plausible feedstock for hydrogen and carbon monoxide generation onboard of a vehicle because of its availability and cost [1]. The ability to process diesel into syngas mixture is very desirable for catalytic emission control, avoiding the heavy pollution related to the use of petroleum derived fuels [2]. The major technological challenge is the development of durable reforming catalysts, overcoming the chemical and mechanical degrade mainly due to the deposition of deleterious carbon species [3]. In this study, the catalytic activity and stability of Pt/CeO2 and Rh/CeO2 catalyst (0.5 wt.% of metal loading) has been comparatively probed towards the steam reforming (SR) of n-dodecane (n-C12H26), as model compound of marine diesel. Catalysts were prepared by combustion synthesis and characterized by XRD, TPR, TEM and CO-Chemisorption analysis. Catalytic tests (TSET=800°C, S/C=1.5-2.5, GHSV=16000-32000 h-1) were conducted employing a temperature-controlled catalytic bed configuration (450?800°C) in order to avoid the carbon formation due to the n-C12H26 cracking phenomena. Both catalysts ensure a total n-dodecane conversion and the production of a syngas with a high H2/CO (4-5) ratio principally due to the contribute of Water Gas Shift reaction (WGS). Pt-based system shows a degradation of catalytic performance due to the deposition of various types of carbon species, as evidenced from the TPO and TEM characterization of spent catalyst. On the other hand, Rh-based catalyst shows stable catalytic activity after 200h of time-on-stream (Fig. 1).