Hydrogen-Mediated Synthesis of 3D Hierarchical Porous Zinc Catalyst for CO₂ Electroreduction with High Current Density

Zn-based catalyst is promising for electrochemical CO₂ reduction (CO₂RR) because of the abundant reserves and good activity. However, a major challenge still remains in simultaneously achieving both large current density and high Faradaic efficiency. Herein, we report a three-dimensional porous Zn catalyst (HP-Zn) for CO₂RR via a simple hydrogen-mediated method, where hydrogen gas bubbles have been utilized as soft templates to generate a series of hierarchical pores in the sample. Benefiting from the high specific surface area (97.2 m² g^–1) and rich mesoporous structure, the as-prepared HP-Zn catalyst displays excellent catalytic activity with a maximum CO Faradaic efficiency of 91.3%, corresponding to a current density of −10.0 mA cm^–2, as well as long-term stability, demonstrating a promising potential for the practical application of CO₂RR.