Title: Ultrathin Pd-Based Perforated Nanosheets for Fuel Cells Electrocatalysis

Abstract: With intriguing physiochemical properties and widespread promising applications, ultrathin nanosheets (NSs) with only atomic thickness have drawn increasing attention. The ultrathin Pd, Pd-based alloy and intermetallic perforated nanosheets (PNSs) have been extensively studied in fuel cells (FCs)-related reactions, including the cathodic oxygen reduction reaction (ORR) and anodic methanol, ethanol, and formic acid oxidation reactions (MOR, EOR, and FAOR). In this review, we briefly summarize the preparation of ultrathin Pd, Pd-based alloy and intermetallic PNSs, as well as their advantages in electrocatalytic applications including ORR, MOR, EOR, and FAOR. Finally, the major challenges and perspectives for future development of ultrathin Pd, Pd-based alloy and intermetallic PNSs electrocatalysts are proposed to accelerate the commercialization of future promising FCs.