Catalyst deactivation in on-board H2 production by fuel dehydrogenation

Abstract

The production of H2 for on-board application is a very interesting challenge for industrial and academic researchers. The aim is the application of on-board hydrogen production on the airplanes using kerosene as H2 source. In this work an in depth study into the partial dehydrogenation (PDH) of two hydrocarbons blends and desulfurized JetA1 fuel has been performed by using 1 wt.%Pt–1 wt.%Sn/γ-Al2O3 and 1 wt.%Pt–1 wt.%Sn–0.5%K/γ-Al2O3 to find a way to produce H2 “on-board” for the feeding of the fuel-cell apparatus. The mechanism of deactivation by coke was studied in depth combining Raman spectroscopy and Temperature-programmed oxidation (TPO) analyses. Microstructure analysis of metallic particles in fresh and deactivated catalysts was investigated by HRTEM. Relatively high H2 partial pressure increases catalyst life by controlling full dehydrogenation coke-forming reaction. By feeding model organic molecules, it was possible to identify the contribution of each class of compounds to the H2 production as well as the amount and type of coke formed. A relatively complex reaction pathway, which is able to evidence the role of different sites and reactions involved in PDH processes, was proposed.