The rising global energy demand and the imperative to mitigate climate change have accelerated the search for alternative

energy carriers. Liquid organic hydrogen carriers (LOHCs) off er a promising solution for hydrogen storage and transport

due to their high stability and compatibility with existing infrastructure. However, conventional LOHC-based hydrogen fuel

cells rely on high-temperature catalytic dehydrogenation for hydrogen release, adding complexity and limiting their practicality.

A direct LOHC fuel cell, which utilizes LOHCs as fuels without requiring separate hydrogen extraction, presents an

alternative approach by simplifying system architecture and enhancing safety. Among potential LOHC candidates, phenolbased

compounds have garnered interest due to their electrochemical reversibility, enabling direct oxidation at the anode.

However, the electrochemical oxidation of dihydroxybenzenes (DHBs), a subclass of phenols, generates phenoxy radicals that

undergo electropolymerization, leading to electrode deactivation. To address this challenge, we systematically investigate the

oxidation behavior of three DHB isomers—catechol, resorcinol, and hydroquinone—at high concentrations and develop an

electrodeposited PtRu alloy catalyst tailored to mitigate polymerization. Our results reveal distinct electrochemical behaviors

among the isomers, with signifi cant variations in polymeric fi lm formation on the electrode surface. Notably, Ru incorporation

into Pt eff ectively suppresses polymer formation while enhancing catalytic activity and durability. The optimized PtRu

catalyst exhibits improved electrochemical performance and stability, demonstrating its viability as an anode material for

direct LOHC fuel cells. These fi ndings underscore the critical role of Ru in enhancing catalytic effi ciency and durability,

providing valuable insights for the rational design of electrocatalysts for direct LOHC fuel cells.