2026 Volume 69 Issue 3 Pages 139-146
The toluene/methylcyclohexane (TOL/MCH) liquid organic hydrogen carrier (LOHC) system is a promising option for safe, high-density hydrogen storage and transport using existing liquid-fuel infrastructure. However, supported Pt catalysts for TOL hydrogenation and MCH dehydrogenation still face key barriers to practical deployment, including high Pt usage, deactivation by poisoning and coke deposition, and a trade-off between reaction rate and durability. This review summarizes recent progress in supported Pt catalysts for both reactions and extracts design principles from the viewpoints of activity, selectivity, stability, and Pt utilization efficiency. Particular emphasis is placed on single-atom alloys (SAAs), in which isolated Pt atoms are anchored on base-metal surfaces to achieve high performance at ultralow Pt loadings. Key concepts highlighted include (i) improved Pt utilization by surface-confined isolated Pt sites, (ii) functional separation where aromatic adsorption occurs on base-metal ensembles while H2 activation proceeds on Pt sites, and (iii) mitigation of coking and product poisoning through sub-nanometric base-metal reaction fields. Recent advances in active-site identification enabled by complementary spectroscopy (e.g., FTIR using CO as a probe molecule, Raman, X-ray absorption fine structure), and density functional theory are also summarized. Finally, opportunities and remaining challenges for “single-atom–base-metal ensemble” design are discussed toward durable, Pt-efficient catalysts for the TOL/MCH cycle.
