Efficient Methylcyclohexane Dehydrogenation Catalysis by Al2O3-Supported Pt-Fe Alloy Cluster Catalysts

Abstract

Abstract Methylcyclohexane (MCH) has emerged as one of the most promising liquid organic hydrogen carriers. The conventional Pt/Al2O3 catalyst for MCH dehydrogenation faces issues of deactivation and low selectivity due to the suboptimal characteristics of Pt. To address these challenges, we developed a Pt-Fe alloy catalyst by modifying Al2O3-supported subnanometer Pt clusters with a sodium ferric ethylenediaminetetraacetate precursor. Spectroscopic and microscopic data reveal that the atomically dispersed Fe dilutes Pt ensemble and modulates its electronic properties through the formation of subnanometer raft-like Pt-Fe alloy, leading to enhanced catalytic stability. Furthermore, Na species suppress the formation of five-membered ring side products, thereby improving the overall selectivity. Remarkably, the Pt-Fe1.2-Na0.6/Al2O3 catalyst demonstrates exceptional performance, including high selectivity and stability, and a high hydrogen evolution rate of 2729 mmol·gPt− 1·min− 1. This superior performance can be attributed to the profound modulation of electronic and geometric properties of Pt within the bimetallic structure, which mitigates coke formation.