Hydrogen Generation from Organic Hydrides under Continuous‐Flow Conditions Using Polymethylphenylsilane‐Aluminum Immobilized Platinum Catalyst

Abstract

Hydrogen is an important resource for realizing the goal of a hydrogen‐based society as well as for synthetic organic chemistry. Catalytic dehydrogenation of organic hydrides such as methyl cyclohexane is attractive for hydrogen storage and transportation in terms of reversibility and selectivity of catalytic reactions and hydrogen storage density. We developed a highly active polymethylphenylsilane‐aluminum immobilized platinum catalyst (Pt/MPPSi‐Al2O3) for dehydrogenation of organic hydrides. Organic hydrides were fully converted into the corresponding aromatic compounds under reactive distillation conditions at 200 °C or under circulation‐flow conditions using the Pt/MPPSi‐Al2O3 catalyst packed in a column at 260 °C. The dehydrogenation reaction reached a maximum conversion at equilibrium (ca. 60%) under continuous‐flow conditions at 260 °C. This catalytic continuous‐flow dehydrogenation was applied to a formal hydrogen transfer from organic hydrides to unsaturated organic substrates under sequential and continuous‐flow conditions for practical flow hydrogenation reactions by connecting two different heterogeneous catalysts packed in columns.

Pt/CB-Catalyzed Chemoselective Hydrogenation Using in situ-Generated Hydrogen by Microwave Mediated Dehydrogenation of Methylcyclohexane under Continuous-Flow Conditions

“…Therefore, significant efforts have been devoted to the development of hydrogen extraction and utilization methods using MCH as a promising material for hydrogen storage applications [29][30][31][32][33][34][35][36]. Kobayashi et al reported the continuous-flow hydrogenation reaction of olefins using H₂ gas extracted from MCH under a parallel catalyst cartridge system, which continuously generated H₂ gas from a heterogeneous Pt catalyst-packed cartridge, and a solution of a substrate possessing an olefin moiety flowed into another heterogeneous Pd catalyst-packed cartridge [37].…”

Pt/CB-Catalyzed Chemoselective Hydrogenation Using In Situ-Generated Hydrogen by Microwave-Mediated Dehydrogenation of Methylcyclohexane under Continuous-Flow Conditions

“…Therefore, significant efforts have been devoted to the development of hydrogen extraction and utilization methods using MCH as a promising material for hydrogen storage applications [29][30][31][32][33][34][35][36]. Kobayashi et al reported the continuous-flow hydrogenation reaction of olefins using H 2 gas extracted from MCH under a parallel catalyst cartridge system, which continuously generated H 2 gas from a heterogeneous Pt catalyst-packed cartridge, with a solution of a substrate possessing an olefin moiety flowing into another heterogeneous Pd catalyst-packed cartridge [37].…”