A Self-Sacrificial Templated Route to Fabricate Multimetal Prussian Blue Analogue/Cu(OH) ₂ Nanoarray for Promoted Electrochemical Methanol Upgrading

Electrochemical methanol upgrading (EMU) represents a sustainable and energy-efficient pathway for producing value-added formate, underscoring the urgent demand for EMU electrocatalysts with enhanced activity and stability. In this work, a multimetal Prussian blue analogue (PBA)/copper hydroxide nanoarray catalyst supported on copper foam (5-PBA/CH/CF) was synthesized via an anodization-self-sacrificial template approach. This strategy synergistically optimizes both active site density and intrinsic activity for efficient EMU to formate. The catalyst leverages multimetal synergy and catalytic ensemble effects to tailor electronic structures. The hierarchical PBA architecture not only exposes abundant high-valence active sites but also provides plentiful reactive sites for enhanced preoxidation, thereby enabling further enrichment of active species. This dual effect concurrently boosts catalytic activity and operational stability. Capitalizing on these structural merits, the 5-PBA/CH/CF catalyst delivers exceptional EMU performance, requiring only 1.355 V vs RHE to achieve 50 mA cm–2 current density while maintaining near 100% Faradaic efficiency (FE) across a broad potential window (1.3–1.5 V vs RHE). Moreover, stability testing over 96 h revealed significant current density enhancement coupled with excellent FE retention. This work establishes a new paradigm for designing highly efficient and ultrastable electrocatalysts for methanol valorization, and provides an efficient and durable catalyst for green electrosynthesis of value-added formate.