High-purity hydrogen production from dehydrogenation of methylcyclohexane catalyzed by zeolite-encapsulated subnanometer platinum-iron clusters

Liquid organic hydrogen carriers (LOHCs) are considered promising carriers for large-scale H2 storage and transportation, among which the toluene-methylcyclohexane cycle has attracted great attention from industry and academia because of the low cost and its compatibility with the current infrastructure facility for the transportation of chemicals. The large-scale deployment of the H2 storage/transportation plants based on the toluene-methylcyclohexane cycle relies on the use of high-performance catalysts, especially for the H2 release process through the dehydrogenation of methylcyclohexane. In this work, we have developed a highly efficient catalyst for MCH dehydrogenation reaction by incorporating subnanometer PtFe clusters with precisely controlled composition and location within a rigid zeolite matrix. The resultant zeolite-encapsulated PtFe clusters exhibit the up-to-date highest reaction rate for dehydrogenation of methylcyclohexane to toluene, very high chemoselectivity to toluene (enabling the production of H2 with purity >99.9%), remarkably high stability (>2000 h) and regenerability over consecutive reaction-regeneration cycles. The large-scale deployment of H2 storage/transportation plants using the toluene-methylcyclohexane cycle depends on high-performance catalysts. Here, subnanometer bimetallic PtFe clusters confined within MFI zeolite demonstrate remarkable activity and stability for the dehydrogenation of methylcyclohexane, offering great potential for H2 storage systems based on liquid organic hydrogen carriers.