Iron (II) phthalocyanine/N-doped graphene: A highly efficient non-precious metal catalyst for oxygen reduction

Non-precious metal electrocatalysts (NPMCs) are a promising alternative to platinum-based catalysts towards the large-scale commercial application of hydrogen fuel cells and metal-air batteries. However, hazardous chemicals or high-temperature pyrolysis are generally involved in the synthesis of these highly-active NPMCs, leading to environmental and safety issues, particularly in scaling up. Exploration of low-cost and straightforward strategies to fabricate high-performance catalysts for ORR are urgently needed. Herein, we report a simple approach to fabricate a new class of the NPMCs by immobilizing iron phthalocyanine (FePc) into a surface of nitrogen-doped electrochemical exfoliated graphene (N-GP950). We highlight that at optimum content of 33 wt% FePc in the composite (FePc-33/N-GP950), the ORR performance significantly improves, exhibiting high current density at 0.8 V (5.0 mA cm⁻²), which is comparable to 4.0 mA cm⁻² of commercial Pt/C in an alkaline media. The optimized sample also displays excellent long-term durability. The present study offers a low cost and straightforward strategy to fabricate inexpensive and durable ORR catalysts for practical hydrogen fuel cells applications and metal-air batteries.