Dehydrogenation of homocyclic liquid organic hydrogen carriers (LOHCs) over Pt supported on an ordered pore structure of 3-D cubic mesoporous KIT-6 silica
Chang‐Il Ahn, Yeonsu Kwak, Ahreum Kim, Munjeong Jang, Arash Badakhsh, Junyoung Cha, Yongmin Kim, Young Suk Jo, Hyangsoo Jeong, Sun Hee Choi, Suk Woo Nam, Chang Won Yoon, Hyuntae Sohn
Abstract
Pt supported on ordered mesoporous silica (KIT-6) catalyst was examined for the dehydrogenation of homocyclic liquid organic hydrogen carriers (LOHCs, 1: MCH, 2: hydrogenated biphenyl-based eutectic mixture (H-BPDM)) conditions. The longer pore-residence time of the MCH molecules in the 3D bicontinuous pore structure of the Pt/KIT-6 catalyst strongly affected the catalytic activity because a higher MCH concentration was achieved in the vicinity of the Pt active sites. Pt/KIT-6 catalyst exhibited a higher surface area, pore volume, and Pt dispersion with narrower particle size distribution (average Pt particle size: ~1.3 nm). Therefore, higher LOHC conversion with faster hydrogen production occurred, with a higher hydrogen selectivity over Pt/KIT-6 compared with Pt/SiO2 and Pt/Al2O3. Long-term experiment results indicated that the Pt/KIT-6 catalytic activity was stable over the reaction time than that of the other catalysts. No significant structural collapse occurred in KIT-6 during the dehydrogenation. Carbon coking was observed for all three samples.