Organophosphine ligand derived sandwich-structural electrocatalyst for oxygen evolution reaction

The synchronous construction of metal phosphate and phosphorus-doped carbon structures is of great significance to innovate the design, synthesis, and application of catalysts, as these phosphoruscontaining composite materials have shown a remarkable contribution to electrocatalysts. However, their preparation procedure generally involves using large amounts of excess phosphorus sources for phosphorization, which inevitably release poisonous PH3 or dangerous phosphorus vapor. Here, a strategy for in-situ formation of FePO4 embedded in P-doped carbon 2D nano film (FePO4/PdC) is developed using a highly integrated precursor, which is a small molecular organophosphine ligand, 1,10bis (diphenylphosphine) ferrocene (DPPF). The multi-source precursor DPPF that contains Fe, P, and C is molecular-vapor-deposited on the nickel foam (NF) supported ZIF-67 nanosheets to obtain the composite catalyst, namely DPPF-500/ZIF-67/NF. FePO4/PdC encapsulated the ZIF-67 derived Co/N-doped carbon matrix (CoNC) to form a sandwich structure FePO4/PdC@CoNC. The constructed catalyst shows good performance for OER, requiring an overpotential of only 297 mV to deliver 600 mA/cm2 with a Tafel slope of 42.7 mV dec-1. DFT calculations demonstrate that the synergistic effects between the metal active center and P-doped carbon film reduce the energy barriers and improve electron transport. This method of constructing P-containing catalysts overcomes the demand for additional P sources to realize eco-friendly fabrication and yields a unique structure with good catalytic activity.(c) 2022 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

The synchronous construction of metal phosphate and phosphorus-doped carbon structures is significant for catalyst design and synthesis, with the potential to improve catalytic activity while eliminating the need for excess phosphorus sources.