Facile synthesis of tin-doped mayenite electride composite as a non-noble metal durable electrocatalyst for oxygen reduction reaction (ORR)

In this study, we synthesized nanosized Sn-doped C12A7:e − (C 12 Al 7− x Sn x :e − , where x = 0.20 to 1) composite with high surface area of 244 m 2 g −1 . An increasing trend in conductivity of Sn-doped C12A7:e − composites was observed at 300 K: 24 S cm −1 , 68 S cm −1 , 190 S cm −1 and 290 S cm −1 , at doping levels of x = 0.20, 0.40, 0.80, and 1, respectively. Sn-doped C12A7:e − , with and without reduced graphene oxide (rGO), acts as a less expensive and highly active and durable electrocatalyst in the oxygen reduction reaction (ORR) for fuel cells. In the case of C 12 A 7− x Sn x :e − (where x = 1), calculated onset potential and current density were comparable to the commercially available 20% Pt/C electrode. Moreover, significant improvement was observed for Sn-doped C12A7:e − (doping level x = 1) with rGO composite. The ORR current density was about 5.9 mA cm −2 , which was higher than that of Pt/C (5.2 mA cm −2 ). Our investigation of the effect of cation doping on structural and electrical properties of Sn-doped C12A7:e − composites shows that these results manifested the feasibility of this sol-gel method for different element doping. Furthermore, the as-prepared promising non-noble metal catalysts (NNMCs), viz ., Sn-doped C12A7:e − composite materials, possess intrinsic long-time stability and excellent methanol resistance toward ORR in alkaline media and may serve as a promising alternative to Pt/C materials for ORR in its widespread implementation in fuel cells. In this study, we synthesized nanosized Sn-doped C12A7:e − (C 12 Al 7− x Sn x :e − , where x = 0.20 to 1) composite with high surface area of 244 m 2 g −1 .