Constructing 3D crosslinked CeO2 nanosheet/graphene architectures anchored with Pd nanoparticles for boosted formic acid and methanol oxidation performance

Abstract

In recent years, there has been growing interest in direct formic acid fuel cells and direct methanol fuel cells due to the diminishing energy resources and escalating environmental concerns, which stimulates the rapid development of advanced anode catalysts towards formic acid and methanol oxidation reactions. This study outlines an efficient bottom-up approach for the controllable fabrication of three-dimensional (3D) crosslinked CeO₂ nanosheet/graphene architectures anchored with Pd nanoparticles (Pd/CeO₂–G) via a solvothermal co-building process. The existence of 3D graphene skeletons introduces numerous pore channels for the fast transportation of reactants and electrons, while the incorporation of CeO₂ nanosheets provides abundant oxygen vacancies to stabilize Pd species as well as reduce CO adsorption on active surfaces. As a result, the as-synthesized Pd/CeO₂–G architectures exhibit impressive electrocatalytic formic acid and methanol oxidation properties including mass activities of 681.0 and 2143.5 mA mg⁻¹ and ECSA values of 107.9 and 115.8 m² g⁻¹ in acidic and alkaline electrolytes, respectively. This makes them more competitive than traditional Pd catalysts supported by carbon black, carbon nanotubes, and graphene matrices.