Stabilizing agents assisted construction of monometallic self-supporting Palladium NCs with ultrafine nanostructures and rich surface area for highly efficient direct ethanol fuel cell

Abstract

Design and construct nanoparticles to develop highly efficient electrocatalysts for energy-associated fuel cells remains a significant challenge. High cost, slow reaction kinetics, and poor durability of catalysts are also essential challenges toward the commercialization of DEFCs. Hence, the optimizationof highly structuredPalladium nanocatalysts (Pd-NCs) with suitable nanostructure, rich surface area, and excellent electrochemical performance is a hot area to explore. Herein, we have successfully developed monometallic Pd-NCs with different nanostructures (nonporous, nanoshere, cubes, and unspecified shapes) via altering the varieties of stabilizing agents (PVA, PVP, AA, CTAB, and SOA) for direct ethanol fuel cells (DEFCs) in alkaline medium. The morphological characterization findings indicate that the monometallic Pd-NCs have ultrafine morphologies with small particle size and large surface areas, indicating the role of stabilizing agents in regulating structures. The obtained CTAB-Pd NCs exhibited promising electrocatalytic activity (5429 mAmgPd-1) toward ethanol oxidation in alkaline medium, which is outperforms SF-Pd NCs (917 mAmgPd-1), PVA-Pd NCs (3458 mAmgPd-1), PVP-Pd NCs (3678 mAmgPd-1), AA-Pd NCs (5126 mAmgPd-1), and SOA-Pd NCs (2196 mAmgPd-1). More impressively, the as-prepared CTAB-Pd NCs demonstrated greater EOR durability and a strong ability to remove CO poisoning to accelerate the overall DEFC system. Therefore, our prepared catalysts represents outstanding EOR performance than most of resent reported catalysts, due to their distinct structures and huge ECSA. This work provides more insight into the structure-regulated nanocatalysts, which will contribute to the rational development of highly-efficient Pd-based electrocatalysts for practical application of DEFCs.