Amorphous CrO x Nano‐Glue Enhancing Hydrogen Evolution Reaction

Reducing catalyst dimensions to the nanoscale is effective to obtain high activity, but raises challenges to integrate them into effective and stable catalysts for macroscopic applications. Herein, we report an amorphous CrO x “nano‐glue” to bind CoP nanoparticles into a stable and efficient monolithic structure for hydrogen evolution reaction (HER). With the interfacial interaction and charge transfer, the CrO x nano‐glue not only consolidates the nanoparticles to ensure structural stability but also actively promotes the water dissociation, as observed by in situ X‐ray absorption spectroscopy and Raman experiments. Consequently, this nano‐glue‐integrated catalyst delivers an outstanding performance in HER, showing a low overpotential of 190 mV (133 mV at 60°C) to achieve the industrial level current density of 1000 mA cm −2 , and can continuously work at this current for over 2000 h. Moreover, it can stably operate in the alkaline seawater at 1000 mA cm −2 for over 1000 h (overpotential of 201 mV). When integrated into a noble‐metal‐free anion exchange membrane cell as the cathode, it can also acquire 1 A cm −2 at 1.63 V (at 80°C) and stably work for over 500 h.