Synergistic Effect of Oxygen Vacancy-Rich SnO 2 and AgCl in the Augmentation of Sustained Oxygen Reduction Reaction.

Developing a stable and methanol-tolerant electrocatalyst for a sustained oxygen reduction reaction (ORR) is of great importance for advancing direct methanol fuel cell applications. The silver-based electrocatalysts are particularly interesting among the promising non-Pt-based electrocatalysts for ORR. Herein, we report a single-step synthesis of a composite of AgCl and SnO 2 with oxygen vacancy (AgCl-SnO 2 (V O )), which exhibits sustained and selective catalytic activity for the ORR along with excellent durability. Hydrothermal synthesis generates oxygen vacancies within the material and facilitates a strong interaction between AgCl and SnO 2 (V O ), which effectively augments the ORR activity and the long-term stability of the composite. The composite exhibits remarkable methanol tolerance, as evidenced by a meager shift of only 0.002 V in the half-wave potential. Furthermore, the composite demonstrates excellent durability, with no noticeable changes in onset and half-wave potential even after 2500 cycles. The cost-effectiveness, durability, and ORR selectivity of this composite hold great promise toward contributing to the advancement of clean energy technology.