“On–off” switch for H₂ and O₂ generation from HCOOH resp. H₂O₂

Abstract In spite of the numerous advances in the development of H₂ and O₂ evolutions upon water splitting, the separation of H₂ from O₂ still remains a severe challenge. Herein, the novel dual‐functional nanocatalysts Pd/carbon nanosphere (CNS), obtained via immobilization of ultrafine Pd nanoparticles onto CNS, are developed and employed for both selective H₂ generation from HCOOH dehydrogenation and O₂ evolution from H₂O₂ decomposition. In these reactions, the highest activities for Pd/CNS‐800 (i.e., calcinated at 800°C) are 2478 h⁻¹ and 993 min⁻¹ for H₂ and O₂ evolution, respectively. The highly efficient and selective “on–off” switch for selective H₂ generation from HCOOH is successfully realized by pH adjustment. This novel and highly efficient nanocatalyst Pd/CNS‐800 not only provides new approaches for the promising application of HCOOH and H₂O₂ as economic and safe H₂ and O₂ carriers, respectively, for fuel cells, but also promotes the development of “on‐off” switch for on‐demand H₂ evolution.