Synthesis of manganese-doped N-C bifunctional electrocatalyst for low-temperature PEM fuel cell

Abstract

PEM fuel cell plays a vital role in ensuring a sustainable future in the energy domain. Electrochemical activities of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) electrocatalysts induce a strong impact on the performance of PEM fuel cells. Bifunctional catalysts capable of facilitating both ORR and OER are crucial for enhancing the overall efficiency and durability of these electrochemical devices. Commercially, Pt/C and RuO₂/C are the available options for PEM fuel cells, which makes the device very costly. Herein, we have prepared a Mn-doped N-C electrocatalyst that shows comparable bifunctional performance as commercial catalysts. The use of naturally occurring sources such as picolinic acid for the synthesis of catalysts over the expensive raw material helps in bringing down the cost. Synthesized electrocatalyst contains mixed oxidation states of Mn (Mn, Mn²⁺, Mn³⁺, Mn⁴⁺), follows 4e⁻ path during the ORR, and for OER, the measured Tafel slope was 19.8 mv/dec with E_oer-10 of 1.617 V and ΔE of 1.004 V, showing promising potential for use in PEM fuel cells.