On H2 supply through liquid organic hydrides - Effect of functional groups

Liquid organic hydride (LOH) based H-2 supply systems possess an excellent potential to overcome the obstacles of upcoming 'hydrogen economy'. However, their efficiency mainly relies on the choice of organic hydride and the dehydrogenation catalyst. In the present study, we focused on the former to strengthen the understanding of H-2 supply through LOH dehydrogenation. We investigated the role of various functionalities viz., methyl group, N heteroatom, cyclic ring and their combinations in LOH dehydrogenation. Several simple representative LOH's such as methylcyclohexane, piperidine, 4-methylpiperidine and decalin were considered and their dehydrogenation was studied over a 5 wt% Pt/ACC catalyst in a spray pulse reactor at 350 degrees C. The H-2 evolution rates were found to follow the trend: cyclohexane < methylcyclohexane < piperidine < 4-methylpiperidine < decalin. The inductive effects caused by these functional groups and their impact on H-2 evolution were comprehensively described. Finally, the results were compared with the benchmark reaction, cyclohexane dehydrogenation to benzene. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.